# publications

title: Altered states: psychedelics and anesthetics.
authors: Icaza EE, Mashour GA.
publication_date: 2013-11-30
doi: 10.1097/01.anes.0000435635.42332.ee
pubmed_id: 24061599
source_url: https://doi.org/10.1097/01.anes.0000435635.42332.ee
substance_tags: psilocybin
topic_tags: Brain Imaging,Mechanism of Action,Consciousness,Aging,Review Article
study_type: Review Article
source_name: Europe PMC
publication_status: published
date_added: 2026-07-01 06:54:14
last_checked: 2026-07-01 11:22:06
abstract:
The psychedelic experience has been reported since antiquity, but there is relatively little known about the underlying neural mechanisms. A recent neuroimaging study on psilocybin revealed a pattern of decreased cerebral blood flow and functional disconnections that is surprisingly similar to that caused by various anesthetics. In this article, the authors review historical examples of psychedelic experiences induced by general anesthetics and then contrast the mechanisms by which these two drug classes generate altered states of consciousness.

keywords:
Humans, Consciousness Disorders, GABA Agents, Anesthetics, Hallucinogens, History, Ancient, History, 19th Century, Psilocybin

raw_json:
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authors: Jastrzebski M, Bala A.
publication_date: 2013-10-31
pubmed_id: 25007546
source_url: https://europepmc.org/article/MED/25007546
substance_tags: psilocybin
topic_tags: Brain Imaging,Pharmacology,Aging
study_type: Other
source_name: Europe PMC
publication_status: published
date_added: 2026-07-01 06:54:14
last_checked: 2026-07-01 11:22:05
title:
[The impact of psilocybin on visual perception and spatial orientation--neuropsychological approach].

abstract:
Psilocybin is a substance of natural origin, occurring in hallucinogenic mushrooms (most common in the Psilocybe family). After its synthesis in 1958 research began on its psychoactive properties, particularly strong effects on visual perception and spatial orientation. Due to the very broad spectrum of psilocybin effects research began on the different ranges of its actions--including the effect on physiological processes (such as eye saccada movements). Neuro-imaging and neurophysiological research (positron emission tomography-PET and electroencephalography-EEG), indicate a change in the rate of metabolism of the brain and desync cerebral hemispheres. Experimental studies show the changes in visual perception and distortion from psilocybin in the handwriting style of patients examined. There are widely described subjective experiences reported by the subjects. There are also efforts to apply testing via questionnaire on people under the influence of psilocybin, in the context of the similarity of psilocybin-induced state to the initial stages of schizophrenia, as well as research aimed at creating an 'artificial' model of the disease.

keywords:
Humans, Agaricales, Substance-Related Disorders, Hallucinogens, Space Perception, Visual Perception, Psychomotor Performance, Dose-Response Relationship, Drug, Psilocybin, Discrimination, Psychological

raw_json:
{"europe_pmc_id":"25007546","source":"MED","pub_type":null,"publisher":null,"importer":"Europe PMC"}


title: Serotonergic hallucinogens as translational models relevant to schizophrenia.
authors: Halberstadt AL, Geyer MA.
publication_date: 2013-08-12
doi: 10.1017/s1461145713000722
pubmed_id: 23942028
source_url: https://doi.org/10.1017/s1461145713000722
substance_tags: psilocybin
topic_tags: Mechanism of Action,Receptor Pharmacology,Review Article,Animal Study,Drug Interactions
study_type: Review Article
source_name: Europe PMC
publication_status: published
date_added: 2026-07-01 06:54:14
last_checked: 2026-07-01 11:22:07
abstract:
One of the oldest models of schizophrenia is based on the effects of serotonergic hallucinogens such as mescaline, psilocybin, and (+)-lysergic acid diethylamide (LSD), which act through the serotonin 5-HT(2A) receptor. These compounds produce a 'model psychosis' in normal individuals that resembles at least some of the positive symptoms of schizophrenia. Based on these similarities, and because evidence has emerged that the serotonergic system plays a role in the pathogenesis of schizophrenia in some patients, animal models relevant to schizophrenia have been developed based on hallucinogen effects. Here we review the behavioural effects of hallucinogens in four of those models, the receptor and neurochemical mechanisms for the effects and their translational relevance. Despite the difficulty of modelling hallucinogen effects in nonverbal species, animal models of schizophrenia based on hallucinogens have yielded important insights into the linkage between 5-HT and schizophrenia and have helped to identify receptor targets and interactions that could be exploited in the development of new therapeutic agents.

keywords:
Brain, Animals, Humans, Disease Models, Animal, Serotonin, Serotonin Agents, Antipsychotic Agents, Hallucinogens, Behavior, Animal, Schizophrenia, Schizophrenic Psychology, Translational Research, Biomedical

raw_json:
{"europe_pmc_id":"23942028","source":"MED","pub_type":null,"publisher":null,"importer":"Europe PMC"}


title: Functional connectivity measures after psilocybin inform a novel hypothesis of early psychosis.
publication_date: 2012-10-07
doi: 10.1093/schbul/sbs117
pubmed_id: 23044373
source_url: https://doi.org/10.1093/schbul/sbs117
substance_tags: psilocybin
topic_tags: Brain Imaging,Default Mode Network,Aging,Healthy Volunteers
study_type: Other
source_name: Europe PMC
publication_status: published
date_added: 2026-07-01 06:54:14
last_checked: 2026-07-01 11:22:05
authors:
Carhart-Harris RL, Leech R, Erritzoe D, Williams TM, Stone JM, Evans J, Sharp DJ, Feilding A, Wise RG, Nutt DJ.

abstract:
Psilocybin is a classic psychedelic and a candidate drug model of psychosis. This study measured the effects of psilocybin on resting-state network and thalamocortical functional connectivity (FC) using functional magnetic resonance imaging (fMRI). Fifteen healthy volunteers received intravenous infusions of psilocybin and placebo in 2 task-free resting-state scans. Primary analyses focused on changes in FC between the default-mode- (DMN) and task-positive network (TPN). Spontaneous activity in the DMN is orthogonal to spontaneous activity in the TPN, and it is well known that these networks support very different functions (ie, the DMN supports introspection, whereas the TPN supports externally focused attention). Here, independent components and seed-based FC analyses revealed increased DMN-TPN FC and so decreased DMN-TPN orthogonality after psilocybin. Increased DMN-TPN FC has been found in psychosis and meditatory states, which share some phenomenological similarities with the psychedelic state. Increased DMN-TPN FC has also been observed in sedation, as has decreased thalamocortical FC, but here we found preserved thalamocortical FC after psilocybin. Thus, we propose that thalamocortical FC may be related to arousal, whereas DMN-TPN FC is related to the separateness of internally and externally focused states. We suggest that this orthogonality is compromised in early psychosis, explaining similarities between its phenomenology and that of the psychedelic state and supporting the utility of psilocybin as a model of early psychosis.

keywords:
Thalamus, Cerebral Cortex, Nerve Net, Humans, Psychoses, Substance-Induced, Hallucinogens, Reproducibility of Results, Psychotic Disorders, Adult, Female, Male, Cerebrum, Young Adult, Connectome, Psilocybin

raw_json:
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authors: Brogaard B.
publication_date: 2013-10-20
doi: 10.3389/fnhum.2013.00657
pubmed_id: 24155703
source_url: https://doi.org/10.3389/fnhum.2013.00657
substance_tags: psilocybin
topic_tags: Mechanism of Action,Receptor Pharmacology
study_type: Other
source_name: Europe PMC
publication_status: published
date_added: 2026-07-01 06:54:14
last_checked: 2026-07-01 11:22:07
title:
Serotonergic hyperactivity as a potential factor in developmental, acquired and drug-induced synesthesia.

abstract:
Though synesthesia research has seen a huge growth in recent decades, and tremendous progress has been made in terms of understanding the mechanism and cause of synesthesia, we are still left mostly in the dark when it comes to the mechanistic commonalities (if any) among developmental, acquired and drug-induced synesthesia. We know that many forms of synesthesia involve aberrant structural or functional brain connectivity. Proposed mechanisms include direct projection and disinhibited feedback mechanisms, in which information from two otherwise structurally or functionally separate brain regions mix. We also know that synesthesia sometimes runs in families. However, it is unclear what causes its onset. Studies of psychedelic drugs, such as psilocybin, LSD and mescaline, reveal that exposure to these drugs can induce synesthesia. One neurotransmitter suspected to be central to the perceptual changes is serotonin. Excessive serotonin in the brain may cause many of the characteristics of psychedelic intoxication. Excessive serotonin levels may also play a role in synesthesia acquired after brain injury. In brain injury sudden cell death floods local brain regions with serotonin and glutamate. This neurotransmitter flooding could perhaps result in unusual feature binding. Finally, developmental synesthesia that occurs in individuals with autism may be a result of alterations in the serotonergic system, leading to a blockage of regular gating mechanisms. I conclude on these grounds that one commonality among at least some cases of acquired, developmental and drug-induced synesthesia may be the presence of excessive levels of serotonin, which increases the excitability and connectedness of sensory brain regions.

raw_json:
{"europe_pmc_id":"24155703","source":"MED","pub_type":null,"publisher":null,"importer":"Europe PMC"}


title: Broadband cortical desynchronization underlies the human psychedelic state.
publication_date: 2013-08-31
doi: 10.1523/jneurosci.2063-13.2013
pubmed_id: 24048847
source_url: https://doi.org/10.1523/jneurosci.2063-13.2013
substance_tags: psilocybin,psilocin
topic_tags: Mechanism of Action,Receptor Pharmacology,Consciousness
study_type: Other
source_name: Europe PMC
publication_status: published
date_added: 2026-07-01 06:54:14
last_checked: 2026-07-01 11:22:05
authors:
Muthukumaraswamy SD, Carhart-Harris RL, Moran RJ, Brookes MJ, Williams TM, Errtizoe D, Sessa B, Papadopoulos A, Bolstridge M, Singh KD, Feilding A, Friston KJ, Nutt DJ.

abstract:
Psychedelic drugs produce profound changes in consciousness, but the underlying neurobiological mechanisms for this remain unclear. Spontaneous and induced oscillatory activity was recorded in healthy human participants with magnetoencephalography after intravenous infusion of psilocybin--prodrug of the nonselective serotonin 2A receptor agonist and classic psychedelic psilocin. Psilocybin reduced spontaneous cortical oscillatory power from 1 to 50 Hz in posterior association cortices, and from 8 to 100 Hz in frontal association cortices. Large decreases in oscillatory power were seen in areas of the default-mode network. Independent component analysis was used to identify a number of resting-state networks, and activity in these was similarly decreased after psilocybin. Psilocybin had no effect on low-level visually induced and motor-induced gamma-band oscillations, suggesting that some basic elements of oscillatory brain activity are relatively preserved during the psychedelic experience. Dynamic causal modeling revealed that posterior cingulate cortex desynchronization can be explained by increased excitability of deep-layer pyramidal neurons, which are known to be rich in 5-HT2A receptors. These findings suggest that the subjective effects of psychedelics result from a desynchronization of ongoing oscillatory rhythms in the cortex, likely triggered by 5-HT2A receptor-mediated excitation of deep pyramidal cells.

keywords:
Cerebral Cortex, Neural Pathways, Humans, Hallucinogens, Electrocardiography, Cortical Synchronization, Magnetoencephalography, Analysis of Variance, Photic Stimulation, Nonlinear Dynamics, Models, Neurological, Rest, Adult, Male, Psilocybin

raw_json:
{"europe_pmc_id":"24048847","source":"MED","pub_type":null,"publisher":null,"importer":"Europe PMC"}


title: Experienced drug users assess the relative harms and benefits of drugs: a web-based survey.
authors: Carhart-Harris RL, Nutt DJ.
publication_date: 2013-08-31
doi: 10.1080/02791072.2013.825034
pubmed_id: 24377171
source_url: https://doi.org/10.1080/02791072.2013.825034
substance_tags: psilocybin
topic_tags: Addiction,Observational Study,Adolescents
study_type: Observational Study
source_name: Europe PMC
publication_status: published
date_added: 2026-07-01 06:54:14
last_checked: 2026-07-01 11:22:06
abstract:
A web-based survey was used to consult the opinions of experienced drug users on matters related to drug harms. We identified a rare sample of 93 drug users with personal experience with 11 different illicit drugs that are widely used in the UK. Asked to assess the relative harms of these drugs, they ranked alcohol and tobacco as the most harmful, and three "Class A" drugs (MDMA, LSD, and psilocybin) and one class B (cannabis) were ranked as the four least harmful drugs. When asked to assess the relative potential for benefit of the 11 drugs, MDMA, LSD, psilocybin, and cannabis were ranked in the top four; and when asked why these drugs are beneficial, rather than simply report hedonic properties, they referred to potential therapeutic applications (e.g., as tools to assist psychotherapy). These results provide a useful insight into the opinions of experienced drug users on a subject about which they have a rare and intimate knowledge.

keywords:
Humans, Data Collection, Knowledge, Internet, Adolescent, Adult, Middle Aged, Female, Male, Drug Users, Illicit Drugs

raw_json:
{"europe_pmc_id":"24377171","source":"MED","pub_type":null,"publisher":null,"importer":"Europe PMC"}


title: A proposal to evaluate mechanistic efficacy of hallucinogens in addiction treatment.
authors: Burdick BV, Adinoff B.
publication_date: 2013-08-31
doi: 10.3109/00952990.2013.811513
pubmed_id: 23968172
source_url: https://doi.org/10.3109/00952990.2013.811513
substance_tags: psilocybin
topic_tags: Addiction,Mystical Experience,Clinical Trial,Randomized Controlled Trial,Safety,Toxicity
study_type: Randomized Controlled Trial
source_name: Europe PMC
publication_status: published
date_added: 2026-07-01 06:54:14
last_checked: 2026-07-01 11:22:07
abstract:
Current treatments for addiction are frequently ineffective. Hallucinogenic therapy has been indicated as helpful for a range of substance use disorders, yet this approach remains understudied and publicly unavailable. It is nonetheless a promising treatment, which has significant, long-term beneficial effects with single doses and a profile characterized by general safety, low toxicity, and non-addictiveness. However, pharmacological interventions, such as hallucinogens, should not be offered if the same effects (e.g. psychological insights/mystical experiences) and outcomes (e.g. decreased drug use) could be achieved absent pharmacological intervention. To date, there have been no clinical comparisons of drug-induced altered states with non-drug-induced states for addiction treatment. We propose and then outline a clinical trial to address this gap in knowledge. The proposed design would evaluate abstinence outcomes in a population of prescription opioid abusers after exposure to one of three conditions: a drug-induced altered state using psilocybin, a non-drug-induced altered state via hyperventilation (Holotropic Breathwork), and an active placebo with niacin. The outcomes of such a study would reveal important differences in therapeutic potential by discriminating hallucinogen-dependent effects from those psychological effects resulting from altered states.

keywords:
Humans, Hyperventilation, Substance-Related Disorders, Opioid-Related Disorders, Hallucinogens, Research Design, Randomized Controlled Trials as Topic, Psilocybin

raw_json:
{"europe_pmc_id":"23968172","source":"MED","pub_type":null,"publisher":null,"importer":"Europe PMC"}


authors: Carhart-Harris RL, Brugger S, Nutt DJ, Stone JM.
publication_date: 2013-06-18
doi: 10.1177/0269881113494107
pubmed_id: 23784738
source_url: https://doi.org/10.1177/0269881113494107
substance_tags: psilocybin
topic_tags: Depression
study_type: Other
source_name: Europe PMC
publication_status: published
date_added: 2026-07-01 06:54:14
last_checked: 2026-07-01 11:22:06
title:
Psychiatry's next top model: cause for a re-think on drug models of psychosis and other psychiatric disorders.

abstract:
Despite the widespread application of drug modelling in psychiatric research, the relative value of different models has never been formally compared in the same analysis. Here we compared the effects of five drugs (cannabis, psilocybin, amphetamine, ketamine and alcohol) in relation to psychiatric symptoms in a two-part subjective analysis. In the first part, mental health professionals associated statements referring to specific experiences, for example 'I don't bother to get out of bed', to one or more psychiatric symptom clusters, for example depression and negative psychotic symptoms. This measured the specificity of an experience for a particular disorder. In the second part, individuals with personal experience with each of the above-listed drugs were asked how reliably each drug produced the experiences listed in part 1, both acutely and sub-acutely. Part 1 failed to find any experiences that were specific for negative or cognitive psychotic symptoms over depression. The best model of positive symptoms was psilocybin and the best models overall were the acute alcohol and amphetamine models of mania. These results challenge current assumptions about drug models and motivate further research on this understudied area.

keywords:
Humans, Cannabis, Psychoses, Substance-Induced, Ethanol, Amphetamine, Ketamine, Pilot Projects, Mental Disorders, Psychiatry, Female, Male, Drug Users, Psilocybin

raw_json:
{"europe_pmc_id":"23784738","source":"MED","pub_type":null,"publisher":null,"importer":"Europe PMC"}


title: Psychedelics and mental health: a population study.
authors: Krebs TS, Johansen PØ.
publication_date: 2013-08-18
doi: 10.1371/journal.pone.0063972
pubmed_id: 23976938
source_url: https://doi.org/10.1371/journal.pone.0063972
substance_tags: psilocybin
topic_tags: Depression,Anxiety,PTSD,Observational Study,Adolescents,Safety
study_type: Observational Study
source_name: Europe PMC
publication_status: published
date_added: 2026-07-01 06:54:14
last_checked: 2026-07-01 11:22:06
abstract:
BackgroundThe classical serotonergic psychedelics LSD, psilocybin, mescaline are not known to cause brain damage and are regarded as non-addictive. Clinical studies do not suggest that psychedelics cause long-term mental health problems. Psychedelics have been used in the Americas for thousands of years. Over 30 million people currently living in the US have used LSD, psilocybin, or mescaline.ObjectiveTo evaluate the association between the lifetime use of psychedelics and current mental health in the adult population.MethodData drawn from years 2001 to 2004 of the National Survey on Drug Use and Health consisted of 130,152 respondents, randomly selected to be representative of the adult population in the United States. Standardized screening measures for past year mental health included serious psychological distress (K6 scale), mental health treatment (inpatient, outpatient, medication, needed but did not receive), symptoms of eight psychiatric disorders (panic disorder, major depressive episode, mania, social phobia, general anxiety disorder, agoraphobia, posttraumatic stress disorder, and non-affective psychosis), and seven specific symptoms of non-affective psychosis. We calculated weighted odds ratios by multivariate logistic regression controlling for a range of sociodemographic variables, use of illicit drugs, risk taking behavior, and exposure to traumatic events.Results21,967 respondents (13.4% weighted) reported lifetime psychedelic use. There were no significant associations between lifetime use of any psychedelics, lifetime use of specific psychedelics (LSD, psilocybin, mescaline, peyote), or past year use of LSD and increased rate of any of the mental health outcomes. Rather, in several cases psychedelic use was associated with lower rate of mental health problems.ConclusionWe did not find use of psychedelics to be an independent risk factor for mental health problems.

keywords:
Humans, Mescaline, Lysergic Acid Diethylamide, Hallucinogens, Data Collection, Odds Ratio, Risk Factors, Mental Health, Mental Disorders, Adolescent, Adult, Middle Aged, United States, Female, Male, Psilocybin

raw_json:
{"europe_pmc_id":"23976938","source":"MED","pub_type":null,"publisher":null,"importer":"Europe PMC"}


title: Effects of psilocybin on hippocampal neurogenesis and extinction of trace fear conditioning.
authors: Catlow BJ, Song S, Paredes DA, Kirstein CL, Sanchez-Ramos J.
publication_date: 2013-06-01
doi: 10.1007/s00221-013-3579-0
pubmed_id: 23727882
source_url: https://doi.org/10.1007/s00221-013-3579-0
substance_tags: psilocybin
topic_tags: PTSD,Neuroplasticity,Neurogenesis,Receptor Pharmacology,Biomarkers,Animal Study
study_type: Animal Study
source_name: Europe PMC
publication_status: published
date_added: 2026-07-01 06:54:14
last_checked: 2026-07-01 11:22:06
abstract:
Drugs that modulate serotonin (5-HT) synaptic concentrations impact neurogenesis and hippocampal (HPC)-dependent learning. The primary objective is to determine the extent to which psilocybin (PSOP) modulates neurogenesis and thereby affects acquisition and extinction of HPC-dependent trace fear conditioning. PSOP, the 5-HT2A agonist 25I-NBMeO and the 5-HT2A/C antagonist ketanserin were administered via an acute intraperitoneal injection to mice. Trace fear conditioning was measured as the amount of time spent immobile in the presence of the conditioned stimulus (CS, auditory tone), trace (silent interval) and post-trace interval over 10 trials. Extinction was determined by the number of trials required to resume mobility during CS, trace and post-trace when the shock was not delivered. Neurogenesis was determined by unbiased counts of cells in the dentate gyrus of the HPC birth-dated with BrdU co-expressing a neuronal marker. Mice treated with a range of doses of PSOP acquired a robust conditioned fear response. Mice injected with low doses of PSOP extinguished cued fear conditioning significantly more rapidly than high-dose PSOP or saline-treated mice. Injection of PSOP, 25I-NBMeO or ketanserin resulted in significant dose-dependent decreases in number of newborn neurons in hippocampus. At the low doses of PSOP that enhanced extinction, neurogenesis was not decreased, but rather tended toward an increase. Extinction of "fear conditioning" may be mediated by actions of the drugs at sites other than hippocampus such as the amygdala, which is known to mediate the perception of fear. Another caveat is that PSOP is not purely selective for 5-HT2A receptors. PSOP facilitates extinction of the classically conditioned fear response, and this, and similar agents, should be explored as potential treatments for post-traumatic stress disorder and related conditions.

keywords:
Hippocampus, Animals, Mice, Inbred C57BL, Mice, Hallucinogens, Fear, Male, Extinction, Psychological, Neurogenesis, Psilocybin, Conditioning, Psychological

raw_json:
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authors: Helander A, Beck O, Hägerkvist R, Hultén P.
publication_date: 2013-05-21
doi: 10.3109/00365513.2013.793817
pubmed_id: 23692208
source_url: https://doi.org/10.3109/00365513.2013.793817
substance_tags: psilocybin,psilocin
topic_tags: Receptor Pharmacology,Adolescents,Safety,Toxicity
study_type: Other
source_name: Europe PMC
publication_status: published
date_added: 2026-07-01 06:54:14
last_checked: 2026-07-01 11:22:07
title:
Identification of novel psychoactive drug use in Sweden based on laboratory analysis--initial experiences from the STRIDA project.

abstract:
AimThe study aimed to collect information concerning the increasing use of new psychoactive substances, commonly sold through online shops as 'Internet drugs' or 'legal highs', or in terms of masked products such as 'bath salts' and 'plant food'.MethodsThe Karolinska Institutet and Karolinska University Laboratory and the Swedish Poisons Information Centre have initiated a project called 'STRIDA' aiming to monitor the occurrence and trends of new psychoactive substances in Sweden, and collect information about their clinical symptoms, toxicity and associated health risks. A liquid chromatographic-tandem mass spectrometric (LC-MS/MS) multi-component method has been developed, currently allowing for the determination of > 80 novel psychoactive compounds or metabolites thereof. This study focused mainly on the particular drug substances identified and the population demographics of the initial STRIDA cases.ResultsIn urine and/or blood samples obtained from 103 consecutive cases of admitted or suspected recreational drug intoxications in mostly young subjects (78% were ≤ 25 years, and 81% were males) presenting at emergency departments all over the country, psychoactive substances were detected in 82%. The substances comprised synthetic cannabinoids ('Spice'; JWH analogues), substituted cathinones ('bath salts'; e.g. butylone, MDPV and methylone) and tryptamines (4-HO-MET), plant-based substances (mitragynine and psilocin), as well as conventional drugs-of-abuse. In 44% of the cases, more than one new psychoactive substance, or a mixture of new and/or conventional drugs were detected.ConclusionThe initial results of the STRIDA project have documented use of a broad variety of new psychoactive substances among mainly young people all over Sweden.

keywords:
Humans, Substance-Related Disorders, Tryptamines, Amphetamines, Methamphetamine, Secologanin Tryptamine Alkaloids, Benzodiazepines, Indoles, Psychotropic Drugs, Adolescent, Adult, Middle Aged, Sweden, Female, Male, Young Adult, Cannabinoid Receptor Agonists, Psilocybin, Illicit Drugs

raw_json:
{"europe_pmc_id":"23692208","source":"MED","pub_type":null,"publisher":null,"importer":"Europe PMC"}


authors: Kjellgren A, Jonsson K.
publication_date: 2013-06-30
doi: 10.1080/02791072.2013.803647
pubmed_id: 24175493
source_url: https://doi.org/10.1080/02791072.2013.803647
substance_tags: psilocybin
topic_tags: Anxiety,Addiction,Consciousness,Emotional Processing,Spirituality,Safety
study_type: Qualitative Study
source_name: Europe PMC
publication_status: published
date_added: 2026-07-01 06:54:14
last_checked: 2026-07-01 11:22:07
title:
Methoxetamine (MXE)--a phenomenological study of experiences induced by a "legal high" from the internet.

abstract:
Methoxetamine (MXE), a ketamine analogue, is one of the new "legal highs" sold on the Internet. The aim of this qualitative study was to provide an initial understanding of what characterizes the experiences induced by MXE. Anonymously written reports (33 persons) on the effects of MXE were collected from public Internet forums and analyzed using the Empirical Phenomenological Psychological Method. The analysis generated 10 themes: (1) preparation, motivation and anticipation; (2) initial effects; (3) malfunction of cognitive processes stabilizing normal state; (4) inner personal processes and learning; (5) emotional processes; (6) altered sensory perception; (7) dissolution and transition; (8) spiritual and transcendental experiences; (9) effects and processes after the experience; (10) re-dosing and addiction. MXE induced a heavily altered state of consciousness. The effects were similar to those induced by classic hallucinogens (such as LSD, psilocybin) and the dissociative ketamine. MXE seemed to have quite a high abuse potential. Beside the positive effects described, negative effects like fear and anxiety were also reported. Acceptance was considered the best coping strategy. Dissolution of identity and body often culminated in spiritual and transcendental experiences. More research is needed on safety issues, how to minimize harm, and the motivation for using legal highs.

keywords:
Humans, Substance-Related Disorders, Cyclohexylamines, Cyclohexanones, Hallucinogens, Motivation, Cognition, Internet, Female, Male, Illicit Drugs

raw_json:
{"europe_pmc_id":"24175493","source":"MED","pub_type":null,"publisher":null,"importer":"Europe PMC"}


authors: Kometer M, Schmidt A, Jäncke L, Vollenweider FX.
publication_date: 2013-05-31
doi: 10.1523/jneurosci.3007-12.2013
pubmed_id: 23785166
source_url: https://doi.org/10.1523/jneurosci.3007-12.2013
substance_tags: psilocybin
topic_tags: Receptor Pharmacology,Consciousness,Observational Study
study_type: Observational Study
source_name: Europe PMC
publication_status: published
date_added: 2026-07-01 06:54:14
last_checked: 2026-07-01 11:22:05
title:
Activation of serotonin 2A receptors underlies the psilocybin-induced effects on α oscillations, N170 visual-evoked potentials, and visual hallucinations.

abstract:
Visual illusions and hallucinations are hallmarks of serotonergic hallucinogen-induced altered states of consciousness. Although the serotonergic hallucinogen psilocybin activates multiple serotonin (5-HT) receptors, recent evidence suggests that activation of 5-HT2A receptors may lead to the formation of visual hallucinations by increasing cortical excitability and altering visual-evoked cortical responses. To address this hypothesis, we assessed the effects of psilocybin (215 μg/kg vs placebo) on both α oscillations that regulate cortical excitability and early visual-evoked P1 and N170 potentials in healthy human subjects. To further disentangle the specific contributions of 5-HT2A receptors, subjects were additionally pretreated with the preferential 5-HT2A receptor antagonist ketanserin (50 mg vs placebo). We found that psilocybin strongly decreased prestimulus parieto-occipital α power values, thus precluding a subsequent stimulus-induced α power decrease. Furthermore, psilocybin strongly decreased N170 potentials associated with the appearance of visual perceptual alterations, including visual hallucinations. All of these effects were blocked by pretreatment with the 5-HT2A antagonist ketanserin, indicating that activation of 5-HT2A receptors by psilocybin profoundly modulates the neurophysiological and phenomenological indices of visual processing. Specifically, activation of 5-HT2A receptors may induce a processing mode in which stimulus-driven cortical excitation is overwhelmed by spontaneous neuronal excitation through the modulation of α oscillations. Furthermore, the observed reduction of N170 visual-evoked potentials may be a key mechanism underlying 5-HT2A receptor-mediated visual hallucinations. This change in N170 potentials may be important not only for psilocybin-induced states but also for understanding acute hallucinatory states seen in psychiatric disorders, such as schizophrenia and Parkinson's disease.

keywords:
Humans, Ketanserin, Receptor, Serotonin, 5-HT2A, Serotonin Antagonists, Hallucinogens, Electroencephalography, Alpha Rhythm, Analysis of Variance, Data Interpretation, Statistical, Double-Blind Method, Photic Stimulation, Consciousness, Psychomotor Performance, Reaction Time, Psychometrics, Evoked Potentials, Visual, Adult, Female, Male, Young Adult, Serotonin Receptor Agonists, Surveys and Questionnaires, Psilocybin

raw_json:
{"europe_pmc_id":"23785166","source":"MED","pub_type":null,"publisher":null,"importer":"Europe PMC"}


authors: Hallock RM, Dean A, Knecht ZA, Spencer J, Taverna EC.
publication_date: 2012-12-20
doi: 10.1016/j.drugalcdep.2012.11.010
pubmed_id: 23265089
source_url: https://doi.org/10.1016/j.drugalcdep.2012.11.010
substance_tags: psilocybin
topic_tags: Addiction,Mystical Experience,Observational Study,Adolescents
study_type: Observational Study
source_name: Europe PMC
publication_status: published
date_added: 2026-07-01 06:54:14
last_checked: 2026-07-01 11:22:06
title:
A survey of hallucinogenic mushroom use, factors related to usage, and perceptions of use among college students.

abstract:
BackgroundRecreational usage and attitudes toward psilocybin-containing hallucinogenic mushrooms among college students are seldom explored.MethodsWe surveyed 882 randomly selected undergraduates at Skidmore College in upstate New York and quantified whether participants had ever used psilocybin mushrooms, their attitudes toward the drug, and polydrug use.ResultsThere were 409 responses and 29.5% of the sample reported psilocybin use. Among users, the mean number of times they reported using mushrooms was 3.4 (mode=1). The top factors cited that influenced their decisions to try hallucinogenic mushrooms for the first time were 'curiosity', 'to achieve a mystical experience', and 'introspection'. Users and non-users had significantly different perceptions of mushrooms: non-users were more likely to say that hallucinogenic mushrooms were addictive and had the potential for abuse than users. Users did not believe that psilocybin negatively impacts their academics, mental health, or physical health, while non-users did. Both users and non-users of psilocybin reported high life-time use of alcohol (97% vs 96%, respectively), marijuana (98% vs 73%, respectively) and tobacco (82% vs 54%, respectively). Psilocybin users were significantly more likely to use other drugs such as cocaine, ecstasy, opiates, non-prescribed prescription drugs, opiates, and lysergic acid diethylamide (LSD) than non-users of psilocybin.ConclusionThis study uncovers important insights into hallucinogenic mushroom use by college students.

keywords:
Humans, Agaricales, Substance-Related Disorders, Hallucinogens, Perception, Students, Universities, Adolescent, Adult, Female, Male, Young Adult, Psilocybin, Illicit Drugs

raw_json:
{"europe_pmc_id":"23265089","source":"MED","pub_type":null,"publisher":null,"importer":"Europe PMC"}


title: Evolution of the toxins muscarine and psilocybin in a family of mushroom-forming fungi.
authors: Kosentka P, Sprague SL, Ryberg M, Gartz J, May AL, Campagna SR, Matheny PB.
publication_date: 2013-05-22
doi: 10.1371/journal.pone.0064646
pubmed_id: 23717644
source_url: https://doi.org/10.1371/journal.pone.0064646
substance_tags: psilocybin
topic_tags: Review Article
study_type: Review Article
source_name: Europe PMC
publication_status: published
date_added: 2026-07-01 06:54:14
last_checked: 2026-07-01 11:22:05
abstract:
Mushroom-forming fungi produce a wide array of toxic alkaloids. However, evolutionary analyses aimed at exploring the evolution of muscarine, a toxin that stimulates the parasympathetic nervous system, and psilocybin, a hallucinogen, have never been performed. The known taxonomic distribution of muscarine within the Inocybaceae is limited, based only on assays of species from temperate regions of the northern hemisphere. Here, we present a review of muscarine and psilocybin assays performed on species of Inocybaceae during the last fifty years. To supplement these results, we used liquid chromatography-tandem mass spectrometry (LC-MS/MS) to determine whether muscarine was present in 30 new samples of Inocybaceae, the majority of which have not been previously assayed or that originated from either the tropics or temperate regions of the southern hemisphere. Our main objective is to test the hypothesis that the presence of muscarine is a shared ancestral feature of the Inocybaceae. In addition, we also test whether species of Inocyabceae that produce psilocybin are monophyletic. Our findings suggest otherwise. Muscarine has evolved independently on several occasions, together with several losses. We also detect at least two independent transitions of muscarine-free lineages to psilocybin-producing states. Although not ancestral for the family as a whole, muscarine is a shared derived trait for an inclusive clade containing three of the seven major lineages of Inocybaceae (the Inocybe, Nothocybe, and Pseudosperma clades), the common ancestor of which may have evolved ca. 60 million years ago. Thus, muscarine represents a conserved trait followed by several recent losses. Transitions to psilocybin from muscarine-producing ancestors occurred more recently between 10-20 million years ago after muscarine loss in two separate lineages. Statistical analyses firmly reject a single origin of muscarine-producing taxa.

keywords:
Animals, Humans, Agaricales, Fruiting Bodies, Fungal, Muscarine, Sequence Analysis, DNA, Evolution, Molecular, Phylogeny, Genetic Speciation, Psilocybin

raw_json:
{"europe_pmc_id":"23717644","source":"MED","pub_type":null,"publisher":null,"importer":"Europe PMC"}


title: [Suicide under the influence of "magic mushrooms"].
authors: Müller K, Püschel K, Iwersen-Bergmann S.
publication_date: 2013-04-30
pubmed_id: 23878898
source_url: https://europepmc.org/article/MED/23878898
substance_tags: psilocybin,psilocin
topic_tags: Case Report
study_type: Case Report
source_name: Europe PMC
publication_status: published
date_added: 2026-07-01 06:54:14
last_checked: 2026-07-01 11:22:04
abstract:
Psilocybin/psilocin from so-called psychoactive mushrooms causes hallucinogenic effects. Especially for people with mental or psychiatric disorders ingestion of magic mushrooms may result in horror trips combined with the intention of self-destruction and suicidal thoughts. Automutilation after consumption of hallucinogenic mushrooms has already been described. Our case report demonstrates the suicide of a man by self-inflicted cut and stab injuries. A causal connection between suicidal behaviour and previous ingestion of psychoactive mushrooms is discussed.

keywords:
Humans, Mushroom Poisoning, Wounds, Stab, Hallucinogens, Diagnosis, Differential, Suicide, Homicide, Expert Testimony, Middle Aged, Male, Psilocybe, Exsanguination, Psilocybin

raw_json:
{"europe_pmc_id":"23878898","source":"MED","pub_type":null,"publisher":null,"importer":"Europe PMC"}


title: Peak experiences of psilocybin users and non-users.
authors: Cummins C, Lyke J.
publication_date: 2013-03-31
doi: 10.1080/02791072.2013.785855
pubmed_id: 23909006
source_url: https://doi.org/10.1080/02791072.2013.785855
substance_tags: psilocybin
topic_tags: Consciousness,Wellbeing,Observational Study,Adolescents
study_type: Observational Study
source_name: Europe PMC
publication_status: published
date_added: 2026-07-01 06:54:14
last_checked: 2026-07-01 11:22:05
abstract:
Maslow (1970) defined peak experiences as the most wonderful experiences of a person's life, which may include a sense of awe, well-being, or transcendence. Furthermore, recent research has suggested that psilocybin can produce experiences subjectively rated as uniquely meaningful and significant (Griffiths et al. 2006). It is therefore possible that psilocybin may facilitate or change the nature of peak experiences in users compared to non-users. This study was designed to compare the peak experiences of psilocybin users and non-users, to evaluate the frequency of peak experiences while under the influence of psilocybin, and to assess the perceived degree of alteration of consciousness during these experiences. Participants were recruited through convenience and snowball sampling from undergraduate classes and at a musical event. Participants were divided into three groups, those who reported a peak experience while under the influence of psilocybin (psilocybin peak experience: PPE), participants who had used psilocybin but reported their peak experiences did not occur while they were under the influence of psilocybin (non-psilocybin peak experience: NPPE), and participants who had never used psilocybin (non-user: NU). A total of 101 participants were asked to think about their peak experiences and complete a measure evaluating the degree of alteration of consciousness during that experience. Results indicated that 47% of psilocybin users reported their peak experience occurred while using psilocybin. In addition, there were significant differences among the three groups on all dimensions of alteration of consciousness. Future research is necessary to identify factors that influence the peak experiences of psilocybin users in naturalistic settings and contribute to the different characteristics of peak experiences of psilocybin users and non-users.

keywords:
Humans, Substance-Related Disorders, Hallucinogens, Multivariate Analysis, Case-Control Studies, Consciousness, Time Factors, Adolescent, Adult, Middle Aged, Female, Male, Drug Users, Young Adult, Surveys and Questionnaires, Psilocybin

raw_json:
{"europe_pmc_id":"23909006","source":"MED","pub_type":null,"publisher":null,"importer":"Europe PMC"}


title: Over 30 million psychedelic users in the United States.
authors: Krebs TS, Johansen PØ.
publication_date: 2013-03-27
doi: 10.12688/f1000research.2-98.v1
pubmed_id: 24627778
source_url: https://doi.org/10.12688/f1000research.2-98.v1
substance_tags: psilocybin
topic_tags: Observational Study
study_type: Observational Study
source_name: Europe PMC
publication_status: published
date_added: 2026-07-01 06:54:14
last_checked: 2026-07-01 11:22:06
abstract:
We estimated lifetime prevalence of psychedelic use (lysergic acid diethylamide (LSD), psilocybin (magic mushrooms), mescaline, and peyote) by age category using data from a 2010 US population survey of 57,873 individuals aged 12 years and older. There were approximately 32 million lifetime psychedelic users in the US in 2010; including 17% of people aged 21 to 64 years (22% of males and 12% of females). Rate of lifetime psychedelic use was greatest among people aged 30 to 34 (total 20%, including 26% of males and 15% of females).

raw_json:
{"europe_pmc_id":"24627778","source":"MED","pub_type":null,"publisher":null,"importer":"Europe PMC"}


authors: Bogenschutz MP.
publication_date: 2013-02-28
doi: 10.2174/15733998113099990002
pubmed_id: 23627783
source_url: https://doi.org/10.2174/15733998113099990002
substance_tags: psilocybin
topic_tags: Addiction,Brain Imaging,Aging,Clinical Trial,Review Article
study_type: Clinical Trial
source_name: Europe PMC
publication_status: published
date_added: 2026-07-01 06:54:14
last_checked: 2026-07-01 11:22:06
title:
Studying the effects of classic hallucinogens in the treatment of alcoholism: rationale, methodology, and current research with psilocybin.

abstract:
Recent developments in the study of classic hallucinogens, combined with a re-appraisal of the older literature, have led to a renewal of interest in possible therapeutic applications for these drugs, notably their application in the treatment of addictions. This article will first provide a brief review of the research literature providing direct and indirect support for the possible therapeutic effects of classic hallucinogens such as psilocybin and lysergic acid diethylamide (LSD) in the treatment of addictions. Having provided a rationale for clinical investigation in this area, we discuss design issues in clinical trials using classic hallucinogens, some of which are unique to this class of drug. We then discuss the current status of this field of research and design considerations in future randomized trials.

keywords:
Brain, Animals, Humans, Substance-Related Disorders, Alcoholism, Hallucinogens, Combined Modality Therapy, Psychotherapy, Research Design, Clinical Trials as Topic, Functional Neuroimaging, Psilocybin

raw_json:
{"europe_pmc_id":"23627783","source":"MED","pub_type":null,"publisher":null,"importer":"Europe PMC"}


authors: Moreno JL, Holloway T, Rayannavar V, Sealfon SC, González-Maeso J.
publication_date: 2013-01-15
doi: 10.1016/j.neulet.2012.12.053
pubmed_id: 23333599
source_url: https://doi.org/10.1016/j.neulet.2012.12.053
substance_tags: psilocybin
topic_tags: Receptor Pharmacology,Animal Study
study_type: Animal Study
source_name: Europe PMC
publication_status: published
date_added: 2026-07-01 06:54:14
last_checked: 2026-07-01 11:22:07
title:
Chronic treatment with LY341495 decreases 5-HT(2A) receptor binding and hallucinogenic effects of LSD in mice.

abstract:
Hallucinogenic drugs, such as lysergic acid diethylamide (LSD), mescaline and psilocybin, alter perception and cognitive processes. All hallucinogenic drugs have in common a high affinity for the serotonin 5-HT(2A) receptor. Metabotropic glutamate 2/3 (mGlu2/3) receptor ligands show efficacy in modulating the cellular and behavioral responses induced by hallucinogenic drugs. Here, we explored the effect of chronic treatment with the mGlu2/3 receptor antagonist 2S-2-amino-2-(1S,2S-2-carboxycyclopropan-1-yl)-3-(xanth-9-yl)-propionic acid (LY341495) on the hallucinogenic-like effects induced by LSD (0.24mg/kg). Mice were chronically (21 days) treated with LY341495 (1.5mg/kg), or vehicle, and experiments were carried out one day after the last injection. Chronic treatment with LY341495 down-regulated [(3)H]ketanserin binding in somatosensory cortex of wild-type, but not mGlu2 knockout (KO), mice. Head-twitch behavior, and expression of c-fos, egr-1 and egr-2, which are responses induced by hallucinogenic 5-HT(2A) agonists, were found to be significantly decreased by chronic treatment with LY341495. These findings suggest that repeated blockade of the mGlu2 receptor by LY341495 results in reduced 5-HT(2A) receptor-dependent hallucinogenic effects of LSD.

keywords:
Somatosensory Cortex, Animals, Mice, Knockout, Mice, Lysergic Acid Diethylamide, Xanthenes, Amino Acids, Proto-Oncogene Proteins c-fos, Receptors, Metabotropic Glutamate, Receptor, Serotonin, 5-HT2A, Hallucinogens, Radioligand Assay, Stereotyped Behavior, Drug Antagonism, Male, Early Growth Response Protein 1, Early Growth Response Protein 2

raw_json:
{"europe_pmc_id":"23333599","source":"MED","pub_type":null,"publisher":null,"importer":"Europe PMC"}


authors: Young SN.
publication_date: 2013-02-28
doi: 10.1503/jpn.120128
pubmed_id: 23171696
source_url: https://doi.org/10.1503/jpn.120128
substance_tags: psilocybin
topic_tags: Depression,Anxiety,Mechanism of Action,Clinical Trial,Animal Study
study_type: Clinical Trial
source_name: Europe PMC
publication_status: published
date_added: 2026-07-01 06:54:14
last_checked: 2026-07-01 11:22:06
title:
Single treatments that have lasting effects: some thoughts on the antidepressant effects of ketamine and botulinum toxin and the anxiolytic effect of psilocybin.

abstract:
Recent clinical trials suggest that 3 single biological treatments have effects that persist. Based on research showing that the muscles involved in facial expressions can feed back to influence mood, a single trial diminishing glabella frown lines with botulinum toxin demonstrated a significant antidepressant effect for 16 weeks. Based primarily on research with animal models of depression suggesting that glutamate may be involved in depression, the N-methyl-D-aspartate antagonist ketamine has been tested in several trials. A single dose decreased depression for up to a week. The reported effects of the use of mushrooms containing psilocybin by a number of cultures around the world has stimulated several trials showing beneficial effects of a single dose of psilocybin for over a year in healthy people, and for up to 3 months in patients with anxiety disorders who have advanced cancer. This article discusses these studies, their rationale, their possible mechanisms of action, the future clinical research required to establish these therapies and the basic research required to optimize single treatments that have lasting effects.

keywords:
Animals, Humans, Ketamine, Anti-Dyskinesia Agents, Anesthetics, Dissociative, Anti-Anxiety Agents, Hallucinogens, Botulinum Toxins, Facial Expression, Treatment Outcome, Attitude, Behavior, Affect, Anxiety Disorders, Depressive Disorder, Placebo Effect, Psilocybin

raw_json:
{"europe_pmc_id":"23171696","source":"MED","pub_type":null,"publisher":null,"importer":"Europe PMC"}


title: Magic truffles or Philosopher's stones: a legal way to sell psilocybin?
authors: Pellegrini M, Rotolo MC, Marchei E, Pacifici R, Saggio F, Pichini S.
publication_date: 2012-08-08
doi: 10.1002/dta.1400
pubmed_id: 22887928
source_url: https://doi.org/10.1002/dta.1400
substance_tags: psilocybin,psilocin
topic_tags: General
study_type: Clinical Trial
source_name: Europe PMC
publication_status: published
date_added: 2026-07-01 06:54:14
last_checked: 2026-07-01 11:22:04
abstract:
"Magic mushrooms" is the most common name given to hallucinogenic fungi containing the psychoactive alkaloids psilocybin and psilocin. In recent years, fungis' sclerotia, commonly called "magic truffles" have become a form of supply of psychoactive Psilocybe alkaloids since Psilocybe sclerotia are not specifically included in the laws banning the sale, the purchase and the use of such substances and mushrooms containing them. A liquid chromatography -tandem mass spectrometry (LC-MS/MS) method was developed for the rapid determination of psilocybin and psilocin in Psilocybe sclerotia. Following a simple step extraction with methanol, the alkaloids were separated on a reversed-phase column using a gradient of 0.1% formic acid - acetonitrile s a mobile phase at a flow rate of 0.2 mL/min.. Separated analytes were detected by electrospray ionization tandem mass spectrometry in the positive ion mode using multiple reaction monitoring. The developed method was linear over the calibration range for all two substances under investigation, with a r(2) > 0.99. The detection and quantification limits were 0.3 µg and 1 µg per 100 mg truffles, for both psilocin and psilocybin and the intra- and inter-day coefficients of variation were always better than 15%. Using this method, the presence of only psilocybin was demonstrated in examined Psilocybe sclerotia. The content of psilocybin was found to vary over a concentration range of 59.3 to 167.8 µg per 100 mg of fresh sclerotia.

keywords:
Hallucinogens, Chromatography, High Pressure Liquid, Time Factors, Tandem Mass Spectrometry, Psilocybe, Limit of Detection, Psilocybin

raw_json:
{"europe_pmc_id":"22887928","source":"MED","pub_type":null,"publisher":null,"importer":"Europe PMC"}


title: Animal models of serotonergic psychedelics.
authors: Hanks JB, González-Maeso J.
publication_date: 2012-09-23
doi: 10.1021/cn300138m
pubmed_id: 23336043
source_url: https://doi.org/10.1021/cn300138m
substance_tags: psilocybin
topic_tags: Anxiety,Mechanism of Action,Receptor Pharmacology,Emotional Processing,Review Article,Animal Study
study_type: Review Article
source_name: Europe PMC
publication_status: published
date_added: 2026-07-01 06:54:14
last_checked: 2026-07-01 11:22:07
abstract:
The serotonin 5-HT(2A) receptor is the major target of psychedelic drugs such as lysergic acid diethylamide (LSD), mescaline, and psilocybin. Serotonergic psychedelics induce profound effects on cognition, emotion, and sensory processing that often seem uniquely human. This raises questions about the validity of animal models of psychedelic drug action. Nonetheless, recent findings suggest behavioral abnormalities elicited by psychedelics in rodents that predict such effects in humans. Here we review the behavioral effects induced by psychedelic drugs in rodent models, discuss the translational potential of these findings, and define areas where further research is needed to better understand the molecular mechanisms and neuronal circuits underlying their neuropsychological effects.

keywords:
Animals, Humans, Rodentia, Mice, Receptors, G-Protein-Coupled, Receptor, Serotonin, 5-HT2A, Hallucinogens, Models, Animal, Exploratory Behavior, Impulsive Behavior, Anxiety, Memory, Reinforcement Schedule, Time Perception, Head Movements, Serotonin 5-HT2 Receptor Agonists, Reflex, Startle, Discrimination, Psychological

raw_json:
{"europe_pmc_id":"23336043","source":"MED","pub_type":null,"publisher":null,"importer":"Europe PMC"}


authors: Schmidt A, Kometer M, Bachmann R, Seifritz E, Vollenweider F.
publication_date: 2012-07-26
doi: 10.1007/s00213-012-2811-0
pubmed_id: 22836372
source_url: https://doi.org/10.1007/s00213-012-2811-0
substance_tags: psilocybin
topic_tags: Receptor Pharmacology,Emotional Processing
study_type: Other
source_name: Europe PMC
publication_status: published
date_added: 2026-07-01 06:54:14
last_checked: 2026-07-01 11:22:05
title:
The NMDA antagonist ketamine and the 5-HT agonist psilocybin produce dissociable effects on structural encoding of emotional face expressions.

abstract:
RationaleBoth glutamate and serotonin (5-HT) play a key role in the pathophysiology of emotional biases. Recent studies indicate that the glutamate N-methyl-D-aspartate (NMDA) receptor antagonist ketamine and the 5-HT receptor agonist psilocybin are implicated in emotion processing. However, as yet, no study has systematically compared their contribution to emotional biases.ObjectivesThis study used event-related potentials (ERPs) and signal detection theory to compare the effects of the NMDA (via S-ketamine) and 5-HT (via psilocybin) receptor system on non-conscious or conscious emotional face processing biases.MethodsS-ketamine or psilocybin was administrated to two groups of healthy subjects in a double-blind within-subject placebo-controlled design. We behaviorally assessed objective thresholds for non-conscious discrimination in all drug conditions. Electrophysiological responses to fearful, happy, and neutral faces were subsequently recorded with the face-specific P100 and N170 ERP.ResultsBoth S-ketamine and psilocybin impaired the encoding of fearful faces as expressed by a reduced N170 over parieto-occipital brain regions. In contrast, while S-ketamine also impaired the encoding of happy facial expressions, psilocybin had no effect on the N170 in response to happy faces.ConclusionThis study demonstrates that the NMDA and 5-HT receptor systems differentially contribute to the structural encoding of emotional face expressions as expressed by the N170. These findings suggest that the assessment of early visual evoked responses might allow detecting pharmacologically induced changes in emotional processing biases and thus provides a framework to study the pathophysiology of dysfunctional emotional biases.

keywords:
Humans, Ketamine, Receptors, Serotonin, Receptors, N-Methyl-D-Aspartate, Excitatory Amino Acid Antagonists, Hallucinogens, Facial Expression, Double-Blind Method, Emotions, Evoked Potentials, Visual, Adult, Female, Male, Young Adult, Serotonin Receptor Agonists, Psilocybin

raw_json:
{"europe_pmc_id":"22836372","source":"MED","pub_type":null,"publisher":null,"importer":"Europe PMC"}


title: Substance use initiation: the role of simultaneous polysubstance use.
authors: Olthuis JV, Darredeau C, Barrett SP.
publication_date: 2012-05-20
doi: 10.1111/j.1465-3362.2012.00470.x
pubmed_id: 22612987
source_url: https://doi.org/10.1111/j.1465-3362.2012.00470.x
substance_tags: psilocybin
topic_tags: Addiction,Adolescents,Safety
study_type: Other
source_name: Europe PMC
publication_status: published
date_added: 2026-07-01 06:54:14
last_checked: 2026-07-01 11:22:07
abstract:
Introduction and aimsSimultaneous polysubstance use (SPU) is a common phenomenon, yet little is known about its role in substance use initiation.Design and methodsIn the present study, 226 cannabis users completed structured interviews about their substance use history. For each substance ever used, participants provided details of their age of first use, their use in the preceding 30 days and whether they co-administered any other licit or illicit substances the first time they used the substance.ResultsFor most illicit substances [powder cocaine, crack, amphetamine, methamphetamine, 3,4-methylenedioxymethamphetamine (MDMA; ecstasy), heroin, opium, gamma-hydroxybutyric acid (GHB), ketamine, psilocybin (magic mushrooms), mescaline, phencyclidine (PCP), peyote and inhalants], results showed that a clear majority of participants (≥75%) reported SPU during their first-ever use of the substance. While SPU was less common on occasions of first use of alcohol, tobacco and cannabis, a high proportion of SPU on occasions of first use of 'harder' drugs could be accounted for by the co-use of alcohol, tobacco and/or cannabis.Discussion and conclusionsSuch findings raise the possibility that specific alcohol, tobacco and/or cannabis use episodes might directly contribute to the initiation of new substance use. Understanding the role of SPU on occasions of first use might help better identify risk factors for substance use progression and improve intervention efforts.

keywords:
Humans, Substance-Related Disorders, Marijuana Abuse, Adolescent, Adult, Middle Aged, Nova Scotia, Female, Male, Young Adult, Prescription Drug Misuse, Illicit Drugs

raw_json:
{"europe_pmc_id":"22612987","source":"MED","pub_type":null,"publisher":null,"importer":"Europe PMC"}


authors: Maclean KA, Leoutsakos JM, Johnson MW, Griffiths RR.
publication_date: 2012-11-30
doi: 10.1111/j.1468-5906.2012.01685.x
pubmed_id: 23316089
source_url: https://doi.org/10.1111/j.1468-5906.2012.01685.x
substance_tags: psilocybin
topic_tags: Spirituality,Mystical Experience
study_type: Other
source_name: Europe PMC
publication_status: published
date_added: 2026-07-01 06:54:14
last_checked: 2026-07-01 11:22:05
title:
Factor Analysis of the Mystical Experience Questionnaire: A Study of Experiences Occasioned by the Hallucinogen Psilocybin.

abstract:
A large body of historical evidence describes the use of hallucinogenic compounds, such as psilocybin mushrooms, for religious purposes. But few scientific studies have attempted to measure or characterize hallucinogen-occasioned spiritual experiences. The present study examined the factor structure of the Mystical Experience Questionnaire (MEQ), a self-report measure that has been used to assess the effects of hallucinogens in laboratory studies. Participants (N=1602) completed the 43-item MEQ in reference to a mystical or profound experience they had had after ingesting psilocybin. Exploratory factor analysis of the MEQ retained 30 items and revealed a 4-factor structure covering the dimensions of classic mystical experience: unity, noetic quality, sacredness (F1); positive mood (F2); transcendence of time/space (F3); and ineffability (F4). MEQ factor scores showed good internal reliability and correlated with the Hood Mysticism Scale, indicating convergent validity. Participants who endorsed having had a mystical experience on psilocybin, compared to those who did not, had significantly higher factor scores, indicating construct validity. The 4-factor structure was confirmed in a second sample (N=440) and demonstrated superior fit compared to alternative models. The results provide initial evidence of the validity, reliability, and factor structure of a 30-item scale for measuring single, hallucinogen-occasioned mystical experiences, which may be a useful tool in the scientific study of mysticism.

raw_json:
{"europe_pmc_id":"23316089","source":"MED","pub_type":null,"publisher":null,"importer":"Europe PMC"}


authors: Kometer M, Schmidt A, Bachmann R, Studerus E, Seifritz E, Vollenweider FX.
publication_date: 2012-05-09
doi: 10.1016/j.biopsych.2012.04.005
pubmed_id: 22578254
source_url: https://doi.org/10.1016/j.biopsych.2012.04.005
substance_tags: psilocybin
topic_tags: Depression,Mechanism of Action,Receptor Pharmacology,Emotional Processing
study_type: Clinical Trial
source_name: Europe PMC
publication_status: published
date_added: 2026-07-01 06:54:14
last_checked: 2026-07-01 11:22:05
title:
Psilocybin biases facial recognition, goal-directed behavior, and mood state toward positive relative to negative emotions through different serotonergic subreceptors.

abstract:
BackgroundSerotonin (5-HT) 1A and 2A receptors have been associated with dysfunctional emotional processing biases in mood disorders. These receptors further predominantly mediate the subjective and behavioral effects of psilocybin and might be important for its recently suggested antidepressive effects. However, the effect of psilocybin on emotional processing biases and the specific contribution of 5-HT2A receptors across different emotional domains is unknown.MethodsIn a randomized, double-blind study, 17 healthy human subjects received on 4 separate days placebo, psilocybin (215 μg/kg), the preferential 5-HT2A antagonist ketanserin (50 mg), or psilocybin plus ketanserin. Mood states were assessed by self-report ratings, and behavioral and event-related potential measurements were used to quantify facial emotional recognition and goal-directed behavior toward emotional cues.ResultsPsilocybin enhanced positive mood and attenuated recognition of negative facial expression. Furthermore, psilocybin increased goal-directed behavior toward positive compared with negative cues, facilitated positive but inhibited negative sequential emotional effects, and valence-dependently attenuated the P300 component. Ketanserin alone had no effects but blocked the psilocybin-induced mood enhancement and decreased recognition of negative facial expression.ConclusionsThis study shows that psilocybin shifts the emotional bias across various psychological domains and that activation of 5-HT2A receptors is central in mood regulation and emotional face recognition in healthy subjects. These findings may not only have implications for the pathophysiology of dysfunctional emotional biases but may also provide a framework to delineate the mechanisms underlying psylocybin's putative antidepressant effects.

keywords:
Cerebral Cortex, Humans, Ketanserin, Receptors, Serotonin, Hallucinogens, Electroencephalography, Double-Blind Method, Emotions, Affect, Goals, Neuropsychological Tests, Evoked Potentials, Adult, Female, Male, Serotonin 5-HT2 Receptor Antagonists, Psilocybin, Recognition, Psychology

raw_json:
{"europe_pmc_id":"22578254","source":"MED","pub_type":null,"publisher":null,"importer":"Europe PMC"}


authors: Lyvers M, Meester M.
publication_date: 2012-10-31
doi: 10.1080/02791072.2012.736842
pubmed_id: 23457892
source_url: https://doi.org/10.1080/02791072.2012.736842
substance_tags: psilocybin
study_type: Observational Study
source_name: Europe PMC
publication_status: published
date_added: 2026-07-01 06:54:14
last_checked: 2026-07-01 11:22:05
title:
Illicit use of LSD or psilocybin, but not MDMA or nonpsychedelic drugs, is associated with mystical experiences in a dose-dependent manner.

abstract:
Psychedelic drugs have long been known to be capable of inducing mystical or transcendental experiences. However, given the common "recreational" nature of much present-day psychedelic use, with typical doses tending to be lower than those commonly taken in the 1960s, the extent to which illicit use of psychedelics today is associated with mystical experiences is not known. Furthermore the mild psychedelic MDMA ("Ecstasy") is more popular today than "full" psychedelics such as LSD or psilocybin, and the contribution of illicit MDMA use to mystical experiences is not known. The present study recruited 337 adults from the website and newsletter of the Multidisciplinary Association for Psychedelic Studies (MAPS), most of whom reported use of a variety of drugs both licit and illicit including psychedelics. Although only a quarter of the sample reported "spiritual" motives for using psychedelics, use of LSD and psilocybin was significantly positively related to scores on two well-known indices of mystical experiences in a dose-related manner, whereas use of MDMA, cannabis, cocaine, opiates and alcohol was not. Results suggest that even in today's context of "recreational" drug use, psychedelics such as LSD and psilocybin, when taken at higher doses, continue to induce mystical experiences in many users.

keywords:
Humans, Consciousness Disorders, N-Methyl-3,4-methylenedioxyamphetamine, Lysergic Acid Diethylamide, Hallucinogens, Depression, Emotions, Anxiety, Empathy, Social Values, Demography, Dose-Response Relationship, Drug, Mysticism, Adolescent, Adult, Aged, Aged, 80 and over, Middle Aged, Female, Male, Young Adult, Surveys and Questionnaires, Psilocybin, Illicit Drugs

topic_tags:
Depression,Anxiety,Addiction,Consciousness,Emotional Processing,Spirituality,Mystical Experience,Observational Study,Adolescents

raw_json:
{"europe_pmc_id":"23457892","source":"MED","pub_type":null,"publisher":null,"importer":"Europe PMC"}


title: A validated method for quantitation of psilocin in plasma by LC-MS/MS and study of stability.
authors: Martin R, Schürenkamp J, Pfeiffer H, Köhler H.
publication_date: 2011-12-02
doi: 10.1007/s00414-011-0652-8
pubmed_id: 22138681
source_url: https://doi.org/10.1007/s00414-011-0652-8
substance_tags: psilocybin,psilocin
topic_tags: General
study_type: Clinical Trial
source_name: Europe PMC
publication_status: published
date_added: 2026-07-01 06:54:14
last_checked: 2026-07-01 11:22:05
abstract:
A liquid chromatography-electrospray ionization/tandem mass spectrometry method for the quantitation of psilocin in plasma is presented. Sample workup was performed with mixed-mode solid-phase extraction using ascorbic acid and nitrogen for drying to protect the unstable analyte. Calibration curves were linear from 2 to 100 ng/mL, and no selectivity problems occurred. The limit of detection was 0.1 ng/mL, and the limit of quantitation was 0.34 ng/mL. Recovery was >86% and matrix effects were

keywords:
Humans, Hallucinogens, Blood Specimen Collection, Chromatography, Liquid, Spectrometry, Mass, Electrospray Ionization, Predictive Value of Tests, Substance Abuse Detection, Dose-Response Relationship, Drug, Tandem Mass Spectrometry, Psilocybin

raw_json:
{"europe_pmc_id":"22138681","source":"MED","pub_type":null,"publisher":null,"importer":"Europe PMC"}


authors: Reissig CJ, Carter LP, Johnson MW, Mintzer MZ, Klinedinst MA, Griffiths RR.
publication_date: 2012-04-12
doi: 10.1007/s00213-012-2680-6
pubmed_id: 22526529
source_url: https://doi.org/10.1007/s00213-012-2680-6
substance_tags: psilocybin
topic_tags: Anxiety,Headache / Migraine,Spirituality,Mystical Experience,Observational Study,Healthy Volunteers
study_type: Observational Study
source_name: Europe PMC
publication_status: published
date_added: 2026-07-01 06:54:14
last_checked: 2026-07-01 11:22:07
title:
High doses of dextromethorphan, an NMDA antagonist, produce effects similar to classic hallucinogens.

abstract:
RationaleAlthough reports of dextromethorphan (DXM) abuse have increased recently, few studies have examined the effects of high doses of DXM.ObjectiveThis study in humans evaluated the effects of supratherapeutic doses of DXM and triazolam.MethodsSingle, acute oral doses of DXM (100, 200, 300, 400, 500, 600, 700, and 800 mg/70 kg), triazolam (0.25 and 0.5 mg/70 kg), and placebo were administered to 12 healthy volunteers with histories of hallucinogen use, under double-blind conditions, using an ascending dose run-up design. Subjective, behavioral, and physiological effects were assessed repeatedly after drug administration for 6 h.ResultsTriazolam produced dose-related increases in subject-rated sedation, observer-rated sedation, and behavioral impairment. DXM produced a profile of dose-related physiological and subjective effects differing from triazolam. DXM effects included increases in blood pressure, heart rate, and emesis; increases in observer-rated effects typical of classic hallucinogens (e.g., distance from reality, visual effects with eyes open and closed, joy, anxiety); and participant ratings of stimulation (e.g., jittery, nervous), somatic effects (e.g., tingling, headache), perceptual changes, end-of-session drug liking, and mystical-type experience. After 400 mg/70 kg DXM, 11 of 12 participants indicated on a pharmacological class questionnaire that they thought they had received a classic hallucinogen (e.g., psilocybin). Drug effects resolved without significant adverse effects by the end of the session. In a 1-month follow-up, volunteers attributed increased spirituality and positive changes in attitudes, moods, and behavior to the session experiences.ConclusionsHigh doses of DXM produced effects distinct from triazolam and had characteristics that were similar to the classic hallucinogen psilocybin.

keywords:
Humans, Dextromethorphan, Triazolam, Excitatory Amino Acid Antagonists, GABA Modulators, Hallucinogens, Follow-Up Studies, Double-Blind Method, Attitude, Affect, Dose-Response Relationship, Drug, Adult, Female, Male, Young Adult, Surveys and Questionnaires, Psilocybin

raw_json:
{"europe_pmc_id":"22526529","source":"MED","pub_type":null,"publisher":null,"importer":"Europe PMC"}


title: Moral transhumanism: the next step.
authors: Tennison MN.
publication_date: 2012-07-31
doi: 10.1093/jmp/jhs024
pubmed_id: 22855738
source_url: https://doi.org/10.1093/jmp/jhs024
keywords: Humans, Biomedical Enhancement, Morals, Bioethics, Philosophy, Medical
substance_tags: psilocybin
topic_tags: Safety
study_type: Other
source_name: Europe PMC
publication_status: published
date_added: 2026-07-01 06:54:14
last_checked: 2026-07-01 11:22:07
abstract:
Although transhumanism offers hope for the transcendence of human biological limitations, it generates many intrinsic and consequential ethical concerns. The latter include issues such as the exacerbation of social inequalities and the exponentially increasing technological capacity to cause harm. To mitigate these risks, many thinkers have initiated investigations into the possibility of moral enhancement that could limit the power disparities facilitated by biotechnological enhancement. The arguments often focus on whether moral enhancement is morally permissible, or even obligatory, and remain largely in the realm of the hypothetical. This paper proposes that psilocybin may represent a viable, practical option for moral enhancement and that its further research in the context of moral psychology could comprise the next step in the development of moral transhumanism.

raw_json:
{"europe_pmc_id":"22855738","source":"MED","pub_type":null,"publisher":null,"importer":"Europe PMC"}


authors: Licht CL, Christoffersen M, Okholm M, Damgaard L, Fink-Jensen A, Knudsen GM, Erritzoe D.
publication_date: 2012-06-13
doi: 10.1002/hup.2234
pubmed_id: 22696164
source_url: https://doi.org/10.1002/hup.2234
substance_tags: psilocybin
topic_tags: Addiction,Observational Study,Adolescents
study_type: Observational Study
source_name: Europe PMC
publication_status: published
date_added: 2026-07-01 06:54:14
last_checked: 2026-07-01 11:22:06
title:
Simultaneous polysubstance use among Danish 3,4-methylenedioxymethamphetamine and hallucinogen users: combination patterns and proposed biological bases.

abstract:
ObjectiveTo describe patterns of simultaneous polysubstance use (SPU) among Danish 3,4-methylenedioxymethamphetamine (MDMA) ("Ecstasy") and hallucinogen users.MethodsA cross-sectional survey of 98 active MDMA and/or hallucinogen users recruited through homepage advertisements, flyers, and word of mouth in Denmark. Lifetime and recent substance use and SPU at last recalled use was described by structured interviews. Hair samples from a subset of participants were analyzed for MDMA.ResultsThe participants had used an average of 12.6 (95% confidence interval: 11.7-13.4) psychoactive substances during their lifetime. SPU was prevalent among MDMA, d-lysergic acid diethylamide (LSD), and psilocybin users, in particular with alcohol and cannabis. Among MDMA users, 69% had combined MDMA with amphetamines, 56% with hallucinogens, and 47% with cocaine. At last recalled use, MDMA was taken with 2.1 ± 1.2 substances in 32 different combinations. The participants preferred specific drug combinations and named several, which in their experience enhanced or counteracted each other. Alcohol and cannabis were typically used before, during, and after MDMA, LSD, and psilocybin, whereas amphetamines were predominantly taken before these substances. When LSD was combined with MDMA, the majority took MDMA after LSD.ConclusionsSimultaneous polysubstance use was common among Danish MDMA and hallucinogen users, and patterns of preferred substance combinations were evident.

keywords:
Hair, Humans, Substance-Related Disorders, N-Methyl-3,4-methylenedioxyamphetamine, Hallucinogens, Data Collection, Cross-Sectional Studies, Substance Abuse Detection, Adolescent, Adult, Denmark, Female, Male, Young Adult, Illicit Drugs

raw_json:
{"europe_pmc_id":"22696164","source":"MED","pub_type":null,"publisher":null,"importer":"Europe PMC"}


title: Psilocybin dose-dependently causes delayed, transient headaches in healthy volunteers.
authors: Johnson MW, Sewell RA, Griffiths RR.
publication_date: 2011-11-28
doi: 10.1016/j.drugalcdep.2011.10.029
pubmed_id: 22129843
source_url: https://doi.org/10.1016/j.drugalcdep.2011.10.029
substance_tags: psilocybin
topic_tags: Headache / Migraine,Mechanism of Action,Healthy Volunteers,Adverse Events
study_type: Other
source_name: Europe PMC
publication_status: published
date_added: 2026-07-01 06:54:14
last_checked: 2026-07-01 11:22:05
abstract:
BackgroundPsilocybin is a well-characterized classic hallucinogen (psychedelic) with a long history of religious use by indigenous cultures, and nonmedical use in modern societies. Although psilocybin is structurally related to migraine medications, and case studies suggest that psilocybin may be efficacious in treatment of cluster headache, little is known about the relationship between psilocybin and headache.MethodsThis double-blind study examined a broad range of psilocybin doses (0, 5, 10, 20, and 30 mg/70 kg) on headache in 18 healthy participants.ResultsPsilocybin frequently caused headache, the incidence, duration, and severity of which increased in a dose-dependent manner. All headaches had delayed onset, were transient, and lasted no more than a day after psilocybin administration.ConclusionsPossible mechanisms for these observations are discussed, and include induction of delayed headache through nitric oxide release. These data suggest that headache is an adverse event to be expected with the nonmedical use of psilocybin-containing mushrooms as well as the administration of psilocybin in human research. Headaches were neither severe nor disabling, and should not present a barrier to future psilocybin research.

keywords:
Humans, Headache, Hallucinogens, Treatment Outcome, Regression Analysis, Cross-Over Studies, Double-Blind Method, Dose-Response Relationship, Drug, Adult, Middle Aged, Educational Status, Female, Male, Psilocybin

raw_json:
{"europe_pmc_id":"22129843","source":"MED","pub_type":null,"publisher":null,"importer":"Europe PMC"}


title: Neuroimaging: a scanner, colourfully.
authors: Roiser JP, Rees G.
publication_date: 2012-03-31
doi: 10.1016/j.cub.2012.02.033
pubmed_id: 22497939
source_url: https://doi.org/10.1016/j.cub.2012.02.033
substance_tags: psilocybin
topic_tags: Depression,Brain Imaging,Aging,Emotional Processing
study_type: Other
source_name: Europe PMC
publication_status: published
date_added: 2026-07-01 06:54:14
last_checked: 2026-07-01 11:22:06
abstract:
Two recent studies report changes in human brain responses after exposure to psilocybin, the active ingredient of hallucinogenic mushrooms. Psilocybin increased sensory cortex responses during emotional recollection, but decreased resting-state blood flow in prefrontal cortex, with potential implications for treating depression.

keywords:
Arteries, Brain, Humans, Oxygen, Hallucinogens, Magnetic Resonance Imaging, Brain Mapping, Memory, Psychotherapy, Cerebrovascular Circulation, Adult, Psilocybin

raw_json:
{"europe_pmc_id":"22497939","source":"MED","pub_type":null,"publisher":null,"importer":"Europe PMC"}


publication_date: 2012-01-25
doi: 10.1192/bjp.bp.111.103309
pubmed_id: 22282432
source_url: https://doi.org/10.1192/bjp.bp.111.103309
substance_tags: psilocybin
topic_tags: Brain Imaging,Aging,Emotional Processing,Clinical Trial,Healthy Volunteers
study_type: Clinical Trial
source_name: Europe PMC
publication_status: published
date_added: 2026-07-01 06:54:14
last_checked: 2026-07-01 11:22:05
title:
Implications for psychedelic-assisted psychotherapy: functional magnetic resonance imaging study with psilocybin.

authors:
Carhart-Harris RL, Leech R, Williams TM, Erritzoe D, Abbasi N, Bargiotas T, Hobden P, Sharp DJ, Evans J, Feilding A, Wise RG, Nutt DJ.

abstract:
BackgroundPsilocybin is a classic psychedelic drug that has a history of use in psychotherapy. One of the rationales for its use was that it aids emotional insight by lowering psychological defences.AimsTo test the hypothesis that psilocybin facilitates access to personal memories and emotions by comparing subjective and neural responses to positive autobiographical memories under psilocybin and placebo.MethodTen healthy participants received two functional magnetic resonance imaging scans (2 mg intravenous psilocybin v. intravenous saline), separated by approximately 7 days, during which they viewed two different sets of 15 positive autobiographical memory cues. Participants viewed each cue for 6 s and then closed their eyes for 16 s and imagined re-experiencing the event. Activations during this recollection period were compared with an equivalent period of eyes-closed rest. We split the recollection period into an early phase (first 8 s) and a late phase (last 8 s) for analysis.ResultsRobust activations to the memories were seen in limbic and striatal regions in the early phase and the medial prefrontal cortex in the late phase in both conditions (P

keywords:
Brain, Humans, Hallucinogens, Placebos, Magnetic Resonance Imaging, Combined Modality Therapy, Brain Mapping, Cross-Over Studies, Emotions, Memory, Psychotherapy, Adult, Female, Male, Memory, Episodic, Psilocybin

raw_json:
{"europe_pmc_id":"22282432","source":"MED","pub_type":null,"publisher":null,"importer":"Europe PMC"}


authors: Schmidt A, Bachmann R, Kometer M, Csomor PA, Stephan KE, Seifritz E, Vollenweider FX.
publication_date: 2011-10-25
doi: 10.1038/npp.2011.261
pubmed_id: 22030715
source_url: https://doi.org/10.1038/npp.2011.261
substance_tags: psilocybin
topic_tags: Mechanism of Action,Receptor Pharmacology,Consciousness,Healthy Volunteers
study_type: Other
source_name: Europe PMC
publication_status: published
date_added: 2026-07-01 06:54:14
last_checked: 2026-07-01 11:22:06
title:
Mismatch negativity encoding of prediction errors predicts S-ketamine-induced cognitive impairments.

abstract:
Psychotomimetics like the N-methyl-D-aspartate receptor (NMDAR) antagonist ketamine and the 5-hydroxytryptamine2A receptor (5-HT(2A)R) agonist psilocybin induce psychotic symptoms in healthy volunteers that resemble those of schizophrenia. Recent theories of psychosis posit that aberrant encoding of prediction errors (PE) may underlie the expression of psychotic symptoms. This study used a roving mismatch negativity (MMN) paradigm to investigate whether the encoding of PE is affected by pharmacological manipulation of NMDAR or 5-HT(2A)R, and whether the encoding of PE under placebo can be used to predict drug-induced symptoms. Using a double-blind within-subject placebo-controlled design, S-ketamine and psilocybin, respectively, were administrated to two groups of healthy subjects. Psychological alterations were assessed using a revised version of the Altered States of Consciousness (ASC-R) questionnaire. As an index of PE, we computed changes in MMN amplitudes as a function of the number of preceding standards (MMN memory trace effect) during a roving paradigm. S-ketamine, but not psilocybin, disrupted PE processing as expressed by a frontally disrupted MMN memory trace effect. Although both drugs produced positive-like symptoms, the extent of PE processing under placebo only correlated significantly with the severity of cognitive impairments induced by S-ketamine. Our results suggest that the NMDAR, but not the 5-HT(2A)R system, is implicated in PE processing during the MMN paradigm, and that aberrant PE signaling may contribute to the formation of cognitive impairments. The assessment of the MMN memory trace in schizophrenia may allow detecting early phases of the illness and might also serve to assess the efficacy of novel pharmacological treatments, in particular of cognitive impairments.

keywords:
Humans, Psychoses, Substance-Induced, Ketamine, Receptors, N-Methyl-D-Aspartate, Excitatory Amino Acid Antagonists, Placebos, Electroencephalography, Double-Blind Method, Cognition Disorders, Schizophrenia, Forecasting, Adult, Female, Male, Young Adult

raw_json:
{"europe_pmc_id":"22030715","source":"MED","pub_type":null,"publisher":null,"importer":"Europe PMC"}


title: Neural correlates of the psychedelic state as determined by fMRI studies with psilocybin.
publication_date: 2012-01-22
doi: 10.1073/pnas.1119598109
pubmed_id: 22308440
source_url: https://doi.org/10.1073/pnas.1119598109
substance_tags: psilocybin
topic_tags: Brain Imaging,Consciousness,Aging,Healthy Volunteers,Drug Interactions
study_type: Other
source_name: Europe PMC
publication_status: published
date_added: 2026-07-01 06:54:14
last_checked: 2026-07-01 11:22:05
authors:
Carhart-Harris RL, Erritzoe D, Williams T, Stone JM, Reed LJ, Colasanti A, Tyacke RJ, Leech R, Malizia AL, Murphy K, Hobden P, Evans J, Feilding A, Wise RG, Nutt DJ.

abstract:
Psychedelic drugs have a long history of use in healing ceremonies, but despite renewed interest in their therapeutic potential, we continue to know very little about how they work in the brain. Here we used psilocybin, a classic psychedelic found in magic mushrooms, and a task-free functional MRI (fMRI) protocol designed to capture the transition from normal waking consciousness to the psychedelic state. Arterial spin labeling perfusion and blood-oxygen level-dependent (BOLD) fMRI were used to map cerebral blood flow and changes in venous oxygenation before and after intravenous infusions of placebo and psilocybin. Fifteen healthy volunteers were scanned with arterial spin labeling and a separate 15 with BOLD. As predicted, profound changes in consciousness were observed after psilocybin, but surprisingly, only decreases in cerebral blood flow and BOLD signal were seen, and these were maximal in hub regions, such as the thalamus and anterior and posterior cingulate cortex (ACC and PCC). Decreased activity in the ACC/medial prefrontal cortex (mPFC) was a consistent finding and the magnitude of this decrease predicted the intensity of the subjective effects. Based on these results, a seed-based pharmaco-physiological interaction/functional connectivity analysis was performed using a medial prefrontal seed. Psilocybin caused a significant decrease in the positive coupling between the mPFC and PCC. These results strongly imply that the subjective effects of psychedelic drugs are caused by decreased activity and connectivity in the brain's key connector hubs, enabling a state of unconstrained cognition.

keywords:
Arteries, Brain, Prefrontal Cortex, Humans, Oxygen, Spin Labels, Hallucinogens, Magnetic Resonance Imaging, Brain Mapping, Perfusion, Cerebrovascular Circulation, Adult, Female, Male, Psilocybin

raw_json:
{"europe_pmc_id":"22308440","source":"MED","pub_type":null,"publisher":null,"importer":"Europe PMC"}


authors: Quednow BB, Kometer M, Geyer MA, Vollenweider FX.
publication_date: 2011-09-27
doi: 10.1038/npp.2011.228
pubmed_id: 21956447
source_url: https://doi.org/10.1038/npp.2011.228
substance_tags: psilocybin,psilocin
topic_tags: Receptor Pharmacology,Consciousness,Observational Study,Healthy Volunteers
study_type: Clinical Trial
source_name: Europe PMC
publication_status: published
date_added: 2026-07-01 06:54:14
last_checked: 2026-07-01 11:22:04
title:
Psilocybin-induced deficits in automatic and controlled inhibition are attenuated by ketanserin in healthy human volunteers.

abstract:
The serotonin-2A receptor (5-HT(2A)R) has been implicated in the pathogenesis of schizophrenia and related inhibitory gating and behavioral inhibition deficits of schizophrenia patients. The hallucinogen psilocybin disrupts automatic forms of sensorimotor gating and response inhibition in humans, but it is unclear so far whether the 5-HT(2A)R or 5-HT(1A)R agonist properties of its bioactive metabolite psilocin account for these effects. Thus, we investigated whether psilocybin-induced deficits in automatic and controlled inhibition in healthy humans could be attenuated by the 5-HT(2A/2C)R antagonist ketanserin. A total of 16 healthy participants received placebo, ketanserin (40 mg p.o.), psilocybin (260 μg/kg p.o.), or psilocybin plus ketanserin in a double-blind, randomized, and counterbalanced order. Sensorimotor gating was measured by prepulse inhibition (PPI) of the acoustic startle response. The effects on psychopathological core dimensions and behavioral inhibition were assessed by the altered states of consciousness questionnaire (5D-ASC), and the Color-Word Stroop Test. Psilocybin decreased PPI at short lead intervals (30 ms), increased all 5D-ASC scores, and selectively increased errors in the interference condition of the Stroop Test. Stroop interference and Stroop effect of the response latencies were increased under psilocybin as well. Psilocybin-induced alterations were attenuated by ketanserin pretreatment, whereas ketanserin alone had no significant effects. These findings suggest that the disrupting effects of psilocybin on automatic and controlled inhibition processes are attributable to 5-HT(2A)R stimulation. Sensorimotor gating and attentional control deficits of schizophrenia patients might be due to changes within the 5-HT(2A)R system.

keywords:
Humans, Ketanserin, Serotonin Antagonists, Hallucinogens, Acoustic Stimulation, Double-Blind Method, Neuropsychological Tests, Adult, Female, Male, Sensory Gating, Reflex, Startle, Surveys and Questionnaires, Psilocybin, Inhibition, Psychological

raw_json:
{"europe_pmc_id":"21956447","source":"MED","pub_type":null,"publisher":null,"importer":"Europe PMC"}


title: Prediction of psilocybin response in healthy volunteers.
authors: Studerus E, Gamma A, Kometer M, Vollenweider FX.
publication_date: 2012-02-16
doi: 10.1371/journal.pone.0030800
pubmed_id: 22363492
source_url: https://doi.org/10.1371/journal.pone.0030800
substance_tags: psilocybin
topic_tags: Anxiety,Personality Change,Emotional Processing,Mystical Experience,Healthy Volunteers
study_type: Other
source_name: Europe PMC
publication_status: published
date_added: 2026-07-01 06:54:14
last_checked: 2026-07-01 11:22:05
abstract:
Responses to hallucinogenic drugs, such as psilocybin, are believed to be critically dependent on the user's personality, current mood state, drug pre-experiences, expectancies, and social and environmental variables. However, little is known about the order of importance of these variables and their effect sizes in comparison to drug dose. Hence, this study investigated the effects of 24 predictor variables, including age, sex, education, personality traits, drug pre-experience, mental state before drug intake, experimental setting, and drug dose on the acute response to psilocybin. The analysis was based on the pooled data of 23 controlled experimental studies involving 409 psilocybin administrations to 261 healthy volunteers. Multiple linear mixed effects models were fitted for each of 15 response variables. Although drug dose was clearly the most important predictor for all measured response variables, several non-pharmacological variables significantly contributed to the effects of psilocybin. Specifically, having a high score in the personality trait of Absorption, being in an emotionally excitable and active state immediately before drug intake, and having experienced few psychological problems in past weeks were most strongly associated with pleasant and mystical-type experiences, whereas high Emotional Excitability, low age, and an experimental setting involving positron emission tomography most strongly predicted unpleasant and/or anxious reactions to psilocybin. The results confirm that non-pharmacological variables play an important role in the effects of psilocybin.

keywords:
Humans, Regression Analysis, Human Experimentation, Models, Biological, Adult, Health, Female, Male, Databases as Topic, Psilocybin

raw_json:
{"europe_pmc_id":"22363492","source":"MED","pub_type":null,"publisher":null,"importer":"Europe PMC"}


title: Psilocybin occasioned mystical-type experiences: immediate and persisting dose-related effects.
authors: Griffiths RR, Johnson MW, Richards WA, Richards BD, McCann U, Jesse R.
publication_date: 2011-06-14
doi: 10.1007/s00213-011-2358-5
pubmed_id: 21674151
source_url: https://doi.org/10.1007/s00213-011-2358-5
substance_tags: psilocybin
topic_tags: Anxiety,Spirituality,Mystical Experience,Observational Study
study_type: Clinical Trial
source_name: Europe PMC
publication_status: published
date_added: 2026-07-01 06:54:14
last_checked: 2026-07-01 11:22:05
abstract:
RationaleThis dose-effect study extends previous observations showing that psilocybin can occasion mystical-type experiences having persisting positive effects on attitudes, mood, and behavior.ObjectivesThis double-blind study evaluated psilocybin (0, 5, 10, 20, 30 mg/70 kg, p.o.) administered under supportive conditions.MethodsParticipants were 18 adults (17 hallucinogen-naïve). Five 8-h sessions were conducted individually for each participant at 1-month intervals. Participants were randomized to receive the four active doses in either ascending or descending order (nine participants each). Placebo was scheduled quasi-randomly. During sessions, volunteers used eyeshades and were instructed to direct their attention inward. Volunteers completed questionnaires assessing effects immediately after and 1 month after each session, and at 14 months follow-up.ResultsPsilocybin produced acute perceptual and subjective effects including, at 20 and/or 30 mg/70 kg, extreme anxiety/fear (39% of volunteers) and/or mystical-type experience (72% of volunteers). One month after sessions at the two highest doses, volunteers rated the psilocybin experience as having substantial personal and spiritual significance, and attributed to the experience sustained positive changes in attitudes, mood, and behavior, with the ascending dose sequence showing greater positive effects. At 14 months, ratings were undiminished and were consistent with changes rated by community observers. Both the acute and persisting effects of psilocybin were generally a monotonically increasing function of dose, with the lowest dose showing significant effects.ConclusionsUnder supportive conditions, 20 and 30 mg/70 kg psilocybin occasioned mystical-type experiences having persisting positive effects on attitudes, mood, and behavior. Implications for therapeutic trials are discussed.

keywords:
Humans, Hallucinogens, Follow-Up Studies, Cross-Over Studies, Double-Blind Method, Attitude, Affect, Spirituality, Dose-Response Relationship, Drug, Time Factors, Adult, Middle Aged, Female, Male, Surveys and Questionnaires, Psilocybin

raw_json:
{"europe_pmc_id":"21674151","source":"MED","pub_type":null,"publisher":null,"importer":"Europe PMC"}


authors: MacLean KA, Johnson MW, Griffiths RR.
publication_date: 2011-09-27
doi: 10.1177/0269881111420188
pubmed_id: 21956378
source_url: https://doi.org/10.1177/0269881111420188
substance_tags: psilocybin
topic_tags: Personality Change,Creativity,Spirituality,Mystical Experience,Randomized Controlled Trial
study_type: Randomized Controlled Trial
source_name: Europe PMC
publication_status: published
date_added: 2026-07-01 06:54:14
last_checked: 2026-07-01 11:22:05
title:
Mystical experiences occasioned by the hallucinogen psilocybin lead to increases in the personality domain of openness.

abstract:
A large body of evidence, including longitudinal analyses of personality change, suggests that core personality traits are predominantly stable after age 30. To our knowledge, no study has demonstrated changes in personality in healthy adults after an experimentally manipulated discrete event. Intriguingly, double-blind controlled studies have shown that the classic hallucinogen psilocybin occasions personally and spiritually significant mystical experiences that predict long-term changes in behaviors, attitudes and values. In the present report we assessed the effect of psilocybin on changes in the five broad domains of personality - Neuroticism, Extroversion, Openness, Agreeableness, and Conscientiousness. Consistent with participant claims of hallucinogen-occasioned increases in aesthetic appreciation, imagination, and creativity, we found significant increases in Openness following a high-dose psilocybin session. In participants who had mystical experiences during their psilocybin session, Openness remained significantly higher than baseline more than 1 year after the session. The findings suggest a specific role for psilocybin and mystical-type experiences in adult personality change.

keywords:
Humans, Hallucinogens, Longitudinal Studies, Follow-Up Studies, Double-Blind Method, Attitude, Behavior, Personality, Mysticism, Adult, Middle Aged, Female, Male, Randomized Controlled Trials as Topic, Young Adult, Psilocybin, Extraversion, Psychological

raw_json:
{"europe_pmc_id":"21956378","source":"MED","pub_type":null,"publisher":null,"importer":"Europe PMC"}


authors: Halberstadt AL, Koedood L, Powell SB, Geyer MA.
publication_date: 2010-12-07
doi: 10.1177/0269881110388326
pubmed_id: 21148021
source_url: https://doi.org/10.1177/0269881110388326
substance_tags: psilocybin,psilocin
topic_tags: Receptor Pharmacology,Animal Study
study_type: Animal Study
source_name: Europe PMC
publication_status: published
date_added: 2026-07-01 06:54:14
last_checked: 2026-07-01 11:22:05
title:
Differential contributions of serotonin receptors to the behavioral effects of indoleamine hallucinogens in mice.

abstract:
Psilocin (4-hydroxy-N,N-dimethyltryptamine) is a hallucinogen that acts as an agonist at 5-HT(1A), 5-HT(2A), and 5-HT(2C) receptors. Psilocin is the active metabolite of psilocybin, a hallucinogen that is currently being investigated clinically as a potential therapeutic agent. In the present investigation, we used a combination of genetic and pharmacological approaches to identify the serotonin (5-HT) receptor subtypes responsible for mediating the effects of psilocin on head twitch response (HTR) and the behavioral pattern monitor (BPM) in C57BL/6J mice. We also compared the effects of psilocin with those of the putative 5-HT(2C) receptor-selective agonist 1-methylpsilocin and the hallucinogen and non-selective serotonin receptor agonist 5-methoxy-N,N-dimethyltryptamine (5-MeO-DMT). Psilocin, 1-methylpsilocin, and 5-MeO-DMT induced the HTR, effects that were absent in mice lacking the 5-HT(2A) receptor gene. When tested in the BPM, psilocin decreased locomotor activity, holepoking, and time spent in the center of the chamber, effects that were blocked by the selective 5-HT(1A) antagonist WAY-100635 but were not altered by the selective 5-HT(2C) antagonist SB242,084 or by 5-HT(2A) receptor gene deletion. 5-MeO-DMT produced similar effects when tested in the BPM, and the action of 5-MeO-DMT was significantly attenuated by WAY-100635. Psilocin and 5-MeO-DMT also decreased the linearity of locomotor paths, effects that were mediated by 5-HT(2C) and 5-HT(1A) receptors, respectively. In contrast to psilocin and 5-MeO-DMT, 1-methylpsilocin (0.6-9.6 mg/kg) was completely inactive in the BPM. These findings confirm that psilocin acts as an agonist at 5-HT(1A), 5-HT(2A), and 5-HT(2C) receptors in mice, whereas the behavioral effects of 1-methylpsilocin indicate that this compound is acting at 5-HT(2A) sites but is inactive at the 5-HT(1A) receptor. The fact that 1-methylpsilocin displays greater pharmacological selectivity than psilocin indicates that 1-methylpsilocin represents a potentially useful alternative to psilocybin for development as a potential therapeutic agent.

keywords:
Animals, Mice, Inbred C57BL, Mice, Knockout, Mice, Methoxydimethyltryptamines, Piperazines, Pyridines, Receptors, Serotonin, Serotonin Antagonists, Hallucinogens, Behavior, Motor Activity, Male, Psilocybin

raw_json:
{"europe_pmc_id":"21148021","source":"MED","pub_type":null,"publisher":null,"importer":"Europe PMC"}


title: Salvia divinorum use and phenomenology: results from an online survey.
authors: Sumnall HR, Measham F, Brandt SD, Cole JC.
publication_date: 2010-10-10
doi: 10.1177/0269881110385596
pubmed_id: 20937616
source_url: https://doi.org/10.1177/0269881110385596
substance_tags: psilocin
topic_tags: Addiction,Receptor Pharmacology,Observational Study
study_type: Observational Study
source_name: Europe PMC
publication_status: published
date_added: 2026-07-01 06:54:14
last_checked: 2026-07-01 11:22:07
abstract:
Salvia divinorum is a hallucinogenic plant with ethnopharmacological and recreational uses. It differs from classic serotonergic hallucinogens such as LSD and psilocin in both phenomenology and potent agonist activity of the active component salvinorin A at κ-opioid receptors. Awareness of S. divinorum has grown recently, with both an increase in its public representation and concern over its potential harmful effects. This discussion is particularly relevant as S. divinorum is legal to use in many countries and regions and easily available through online retailers. Drawing upon previous investigations of S. divinorum and other hallucinogens, this study surveyed 154 recent users and questioned them on their use behaviours, consequences of use and other attitudinal measures. Although reporting an extensive substance use history, and considering the limitations of online surveys, there was little evidence of dysfunctional S. divinorum use, and few reports of troubling adverse consequences of use. Furthermore, there was no evidence that users exhibited increased schizotypy. Respondents reported that S. divinorum produced mixed hallucinogenic and dissociative effects, which lends support to assertions that it phenomenologically differs from other hallucinogens with primary serotonergic activity. The functions of use changed with greater experiences with the drug, and although many respondents reported use of S. divinorum as an alternative to illegal drugs it, was apparent that legal proscription would be unlikely to dissuade them from use. These results are discussed with reference to psychopharmacologically informed public health responses to substance use.

keywords:
Humans, Salvia, Salvia miltiorrhiza, Diterpenes, Clerodane, Receptors, Opioid, kappa, Hallucinogens, Drugs, Chinese Herbal, Data Collection, Public Health, Internet, Female, Male, Panax notoginseng, Young Adult, Camphanes, Illicit Drugs

raw_json:
{"europe_pmc_id":"20937616","source":"MED","pub_type":null,"publisher":null,"importer":"Europe PMC"}


authors: Studerus E, Kometer M, Hasler F, Vollenweider FX.
publication_date: 2010-09-19
doi: 10.1177/0269881110382466
pubmed_id: 20855349
source_url: https://doi.org/10.1177/0269881110382466
substance_tags: psilocybin
topic_tags: Anxiety,Observational Study,Safety,Adverse Events
study_type: Observational Study
source_name: Europe PMC
publication_status: published
date_added: 2026-07-01 06:54:14
last_checked: 2026-07-01 11:22:06
title:
Acute, subacute and long-term subjective effects of psilocybin in healthy humans: a pooled analysis of experimental studies.

abstract:
Psilocybin and related hallucinogenic compounds are increasingly used in human research. However, due to limited information about potential subjective side effects, the controlled medical use of these compounds has remained controversial. We therefore analysed acute, short- and long-term subjective effects of psilocybin in healthy humans by pooling raw data from eight double-blind placebo-controlled experimental studies conducted between 1999 and 2008. The analysis included 110 healthy subjects who had received 1-4 oral doses of psilocybin (45-315 µg/kg body weight). Although psilocybin dose-dependently induced profound changes in mood, perception, thought and self-experience, most subjects described the experience as pleasurable, enriching and non-threatening. Acute adverse drug reactions, characterized by strong dysphoria and/or anxiety/panic, occurred only in the two highest dose conditions in a relatively small proportion of subjects. All acute adverse drug reactions were successfully managed by providing interpersonal support and did not need psychopharmacological intervention. Follow-up questionnaires indicated no subsequent drug abuse, persisting perception disorders, prolonged psychosis or other long-term impairment of functioning in any of our subjects. The results suggest that the administration of moderate doses of psilocybin to healthy, high-functioning and well-prepared subjects in the context of a carefully monitored research environment is associated with an acceptable level of risk.

keywords:
Humans, Hallucinogens, Follow-Up Studies, Double-Blind Method, Affect, Perception, Adult, Middle Aged, Female, Male, Young Adult, Surveys and Questionnaires, Psilocybin

raw_json:
{"europe_pmc_id":"20855349","source":"MED","pub_type":null,"publisher":null,"importer":"Europe PMC"}


authors: Carhart-Harris RL, Williams TM, Sessa B, Tyacke RJ, Rich AS, Feilding A, Nutt DJ.
publication_date: 2010-04-14
doi: 10.1177/0269881110367445
pubmed_id: 20395317
source_url: https://doi.org/10.1177/0269881110367445
substance_tags: psilocybin
topic_tags: Brain Imaging,Aging,Safety
study_type: Other
source_name: Europe PMC
publication_status: published
date_added: 2026-07-01 06:54:14
last_checked: 2026-07-01 11:22:06
title:
The administration of psilocybin to healthy, hallucinogen-experienced volunteers in a mock-functional magnetic resonance imaging environment: a preliminary investigation of tolerability.

abstract:
This study sought to assess the tolerability of intravenously administered psilocybin in healthy, hallucinogen-experienced volunteers in a mock-magnetic resonance imaging environment as a preliminary stage to a controlled investigation using functional magnetic resonance imaging to explore the effects of psilocybin on cerebral blood flow and activity. The present pilot study demonstrated that up to 2 mg of psilocybin delivered as a slow intravenous injection produces short-lived but typical drug effects that are psychologically and physiologically well tolerated. With appropriate care, this study supports the viability of functional magnetic resonance imaging work with psilocybin.

keywords:
Humans, Hallucinogens, Magnetic Resonance Imaging, Injections, Intravenous, Follow-Up Studies, Pilot Projects, Cerebrovascular Circulation, Drug Tolerance, Adult, Middle Aged, Female, Male, Psilocybin

raw_json:
{"europe_pmc_id":"20395317","source":"MED","pub_type":null,"publisher":null,"importer":"Europe PMC"}


title: Iconography in Bradshaw rock art: breaking the circularity.
authors: Pettigrew J.
publication_date: 2011-08-31
doi: 10.1111/j.1444-0938.2011.00648.x
pubmed_id: 21884255
source_url: https://doi.org/10.1111/j.1444-0938.2011.00648.x
substance_tags: psilocybin
topic_tags: Observational Study
study_type: Observational Study
source_name: Europe PMC
publication_status: published
date_added: 2026-07-01 06:54:14
last_checked: 2026-07-01 11:22:07
abstract:
BackgroundInterpreting the symbols found in the rock art of an extinct culture is hampered by the fact that such symbols are culturally determined. How does one break the circularity inherent in the fact that the knowledge of both the symbols and the culture comes from the same source? In this study, the circularity is broken for the Bradshaw rock art of the Kimberley by seeking anchors from outside the culture.MethodsBradshaw rock art in the Kimberley region of Australia and Sandawe rock art in the Kolo region of Eastern Tanzania were surveyed in six visits on foot, by vehicle, by helicopter and from published or shared images, as well as from the published and online images of Khoisan rock art.ResultsUniquely shared images between Bradshaw and Sandawe art, such as the 'mushroom head' symbol of psilocybin use, link the two cultures and indicate that they were shamanistic. Therefore, many mysterious features in the art can be understood in terms of trance visualisations. A number of other features uniquely link Bradshaw and Sandawe cultures, such as a special affinity for small mammals. There are also many references to baobabs in early Bradshaw art but not later. This can be explained in the context of the Toba super-volcano, the likely human transport of baobabs to the Kimberley and the extraordinary utility of the baobab.ConclusionMany more mysterious symbols in Bradshaw rock art might await interpretation using the approaches adopted here.

keywords:
Humans, Adansonia, Hallucinogens, Shamanism, Art, History, Ancient, Symbolism, Africa, Australia, Psilocybin

raw_json:
{"europe_pmc_id":"21884255","source":"MED","pub_type":null,"publisher":null,"importer":"Europe PMC"}


title: Multiple receptors contribute to the behavioral effects of indoleamine hallucinogens.
authors: Halberstadt AL, Geyer MA.
publication_date: 2011-01-19
doi: 10.1016/j.neuropharm.2011.01.017
pubmed_id: 21256140
source_url: https://doi.org/10.1016/j.neuropharm.2011.01.017
substance_tags: psilocybin
topic_tags: End-of-Life Distress,Neuroplasticity,Receptor Pharmacology,Review Article,Drug Interactions
study_type: Review Article
source_name: Europe PMC
publication_status: published
date_added: 2026-07-01 06:54:14
last_checked: 2026-07-01 11:22:07
abstract:
Serotonergic hallucinogens produce profound changes in perception, mood, and cognition. These drugs include phenylalkylamines such as mescaline and 2,5-dimethoxy-4-methylamphetamine (DOM), and indoleamines such as (+)-lysergic acid diethylamide (LSD) and psilocybin. Despite their differences in chemical structure, the two classes of hallucinogens produce remarkably similar subjective effects in humans, and induce cross-tolerance. The phenylalkylamine hallucinogens are selective 5-HT(2) receptor agonists, whereas the indoleamines are relatively non-selective for serotonin (5-HT) receptors. There is extensive evidence, from both animal and human studies, that the characteristic effects of hallucinogens are mediated by interactions with the 5-HT(2A) receptor. Nevertheless, there is also evidence that interactions with other receptor sites contribute to the psychopharmacological and behavioral effects of the indoleamine hallucinogens. This article reviews the evidence demonstrating that the effects of indoleamine hallucinogens in a variety of animal behavioral paradigms are mediated by both 5-HT(2) and non-5-HT(2) receptors.

keywords:
Neurons, Presynaptic Terminals, Animals, Humans, Serotonin Syndrome, Phenethylamines, Lysergic Acid Diethylamide, Receptors, Serotonin, Receptor, Serotonin, 5-HT2A, Nerve Tissue Proteins, Hallucinogens, Behavior, Behavior, Animal, Synaptic Transmission, Serotonin Receptor Agonists, Psilocybin, Selective Serotonin Reuptake Inhibitors

raw_json:
{"europe_pmc_id":"21256140","source":"MED","pub_type":null,"publisher":null,"importer":"Europe PMC"}


title: Heaven and hell--a phenomenological study of recreational use of 4-HO-MET in Sweden.
authors: Kjellgren A, Soussan C.
publication_date: 2011-06-30
doi: 10.1080/02791072.2011.605699
pubmed_id: 22111404
source_url: https://doi.org/10.1080/02791072.2011.605699
substance_tags: psilocybin
topic_tags: Emotional Processing,Adolescents
study_type: Qualitative Study
source_name: Europe PMC
publication_status: published
date_added: 2026-07-01 06:54:14
last_checked: 2026-07-01 11:22:07
abstract:
The psychoactive substance 4-HO-MET (4-hydroxy-N-methyl-N-ethyltryptamine) with psychedelic qualities is one of many legal so-called Internet drugs. The aim of this qualitative study was to establish an understanding of what characterizes its recreational use. Very little is known about the effects of this substance. Twenty-five anonymous Swedish experience reports (from persons aged 18-30 years) from public Internet forums were analyzed using the Empirical Phenomenological Psychological Method. The analysis produced 37 categories that were compiled into nine general themes: (1) motivation, preparation and expectation; (2) initial effects; (3) change of perception; (4) unfiltered awareness and intensified flow of information; (5) lateral cognition; (6) border between subject and object is erased; (7) heaven; (8) hell; and (9) subsiding effects. An understanding of the chronological happenings, called The Process, appeared out of the general structure. Drastic changes in cognitive, emotional and bodily functions were described. The motivation for use seemed to be driven by a strong curiosity. The experiences shifted between "heaven" and "hell," but participants appeared satisfied and ready to repeat the experience. The experiences described show great similarity with classic psychedelic substances as LSD or psilocybin. More research is needed about health hazards or possible therapeutic potentials.

keywords:
Humans, Tryptamines, Hallucinogens, Health Knowledge, Attitudes, Practice, Emotions, Motivation, Mental Processes, Cognition, Awareness, Perception, Qualitative Research, Internet, Adolescent, Adult, Sweden, Female, Male, Young Adult, Consumer Behavior, Illicit Drugs

raw_json:
{"europe_pmc_id":"22111404","source":"MED","pub_type":null,"publisher":null,"importer":"Europe PMC"}


title: Voice of the psychonauts: coping, life purpose, and spirituality in psychedelic drug users.
authors: Móró L, Simon K, Bárd I, Rácz J.
publication_date: 2011-06-30
doi: 10.1080/02791072.2011.605661
pubmed_id: 22111402
source_url: https://doi.org/10.1080/02791072.2011.605661
substance_tags: psilocybin
topic_tags: Spirituality,Observational Study,Adolescents,Immune Function
study_type: Observational Study
source_name: Europe PMC
publication_status: published
date_added: 2026-07-01 06:54:14
last_checked: 2026-07-01 11:22:07
abstract:
Psychoactive drug use shows great diversity, but due to a disproportionate focus on problematic drug use, predominant nonproblematic drug use remains an understudied phenomenon. Historic and anecdotal evidence shows that natural sources of "psychedelic" drugs (e.g., mescaline and psilocybin) have been used in religious and spiritual settings for centuries, as well as for psychological self-enhancement purposes. Our study assessed a total of 667 psychedelic drug users, other drug users, and drug nonusers by online questionnaires. Coping, life purpose, and spirituality were measured with the Psychological Immune Competence Inventory, the Purpose in Life test, and the Intrinsic Spirituality Scale, respectively. Results indicate that the use of psychedelic drugs with a purpose to enhance self-knowledge is less associated with problems, and correlates positively with coping and spirituality. Albeit the meaning of "spirituality" may be ambiguous, it seems that a spiritually-inclined attitude in drug use may act as a protective factor against drug-related problems. The autognostic use of psychedelic drugs may be thus hypothesized as a "training situation" that promotes self-enhancement by rehearsing personal coping strategies and by gaining self-knowledge. However, to assess the actual efficiency and the speculated long-term benefits of these deliberately provoked exceptional experiences, further qualitative investigations are needed.

keywords:
Humans, Hallucinogens, Self Administration, Adaptation, Psychological, Spirituality, Quality of Life, Internet, Adolescent, Adult, Middle Aged, Female, Male, Young Adult, Self-Assessment, Surveys and Questionnaires

raw_json:
{"europe_pmc_id":"22111402","source":"MED","pub_type":null,"publisher":null,"importer":"Europe PMC"}


authors: Moreno JL, Holloway T, Albizu L, Sealfon SC, González-Maeso J.
publication_date: 2011-01-26
doi: 10.1016/j.neulet.2011.01.046
pubmed_id: 21276828
source_url: https://doi.org/10.1016/j.neulet.2011.01.046
substance_tags: psilocybin
topic_tags: Mechanism of Action,Receptor Pharmacology,Animal Study,Drug Interactions
study_type: Animal Study
source_name: Europe PMC
publication_status: published
date_added: 2026-07-01 06:54:14
last_checked: 2026-07-01 11:22:07
title:
Metabotropic glutamate mGlu2 receptor is necessary for the pharmacological and behavioral effects induced by hallucinogenic 5-HT2A receptor agonists.

abstract:
Hallucinogenic drugs, including mescaline, psilocybin and lysergic acid diethylamide (LSD), act at serotonin 5-HT2A receptors (5-HT2ARs). Metabotropic glutamate receptor 2/3 (mGluR2/3) ligands show efficacy in modulating the responses induced by activation of 5-HT2ARs. The formation of a 5-HT2AR-mGluR2 complex suggests a functional interaction that affects the hallucinogen-regulated cellular signaling pathways. Here, we tested the cellular and behavioral effects of hallucinogenic 5-HT2AR agonists in mGluR2 knockout (mGluR2-KO) mice. Mice were intraperitoneally injected with the hallucinogens DOI (2 mg/kg) and LSD (0.24 mg/kg), or vehicle. Head-twitch behavioral response, expression of c-fos, which is induced by all 5-HT2AR agonists, and expression of egr-2, which is hallucinogen-specific, were determined in wild type and mGluR2-KO mice. [(3)H]Ketanserin binding displacement curves by DOI were performed in mouse frontal cortex membrane preparations. Head twitch behavior was abolished in mGluR2-KO mice. The high-affinity binding site of DOI was undetected in mGluR2-KO mice. The hallucinogen DOI induced c-fos in both wild type and mGluR2-KO mice. However, the induction of egr-2 by DOI was eliminated in mGlu2-KO mice. These findings suggest that the 5-HT2AR-mGluR2 complex is necessary for the neuropsychological responses induced by hallucinogens.

keywords:
Frontal Lobe, Animals, Mice, Knockout, Mice, Receptors, Metabotropic Glutamate, Receptor, Serotonin, 5-HT2A, Hallucinogens, Behavior, Animal, Schizophrenia, Signal Transduction, Protein Binding, Genes, fos, Male, Early Growth Response Protein 2, Mice, 129 Strain, Serotonin 5-HT2 Receptor Agonists

raw_json:
{"europe_pmc_id":"21276828","source":"MED","pub_type":null,"publisher":null,"importer":"Europe PMC"}


title: Harm potential of magic mushroom use: a review.
authors: van Amsterdam J, Opperhuizen A, van den Brink W
journal: Regulatory toxicology and pharmacology : RTP
publication_date: 2011-03-31
doi: 10.1016/j.yrtph.2011.01.006
pubmed_id: 21256914
source_url: https://pubmed.ncbi.nlm.nih.gov/21256914/
substance_tags: psilocybin
topic_tags: Review Article,Safety,Toxicity,Abuse Liability
study_type: Review Article
source_name: PubMed
publication_status: published
date_added: 2026-07-01 06:54:14
last_checked: 2026-07-01 06:54:14
raw_json: {"pubmed_id":"21256914"}
abstract:
In 2007, the Minister of Health of the Netherlands requested the CAM (Coordination point Assessment and Monitoring new drugs) to assess the overall risk of magic mushrooms. The present paper is an updated redraft of the review, written to support the assessment by CAM experts. It summarizes the literature on physical or psychological dependence, acute and chronic toxicity, risk for public health and criminal aspects related to the consumption of magic mushrooms. In the Netherlands, the prevalence of magic mushroom use was declining since 2000 (last year prevalence of 6.3% in 2000 to 2.9% in 2005), and further declined after possession and use became illegal in December 2008. The CAM concluded that the physical and psychological dependence potential of magic mushrooms was low, that acute toxicity was moderate, chronic toxicity low and public health and criminal aspects negligible. The combined use of mushrooms and alcohol and the quality of the setting in which magic mushrooms are used deserve, however, attention. In conclusion, the use of magic mushrooms is relatively safe as only few and relatively mild adverse effects have been reported. The low prevalent but unpredictable provocation of panic attacks and flash-backs remain, however, a point of concern.


title: Alternative headache treatments: nutraceuticals, behavioral and physical treatments.
authors: Sun-Edelstein C, Mauskop A.
publication_date: 2011-02-28
doi: 10.1111/j.1526-4610.2011.01846.x
pubmed_id: 21352222
source_url: https://doi.org/10.1111/j.1526-4610.2011.01846.x
substance_tags: psilocybin
topic_tags: Headache / Migraine,Review Article
study_type: Review Article
source_name: Europe PMC
publication_status: published
date_added: 2026-07-01 06:54:14
last_checked: 2026-07-01 11:22:07
abstract:
There is a growing body of evidence supporting the efficacy of various complementary and alternative medicine approaches in the management of headache disorders. These treatment modalities include nutraceutical, physical and behavioral therapies. Nutraceutical options comprise vitamins and supplements (magnesium, riboflavin, coenzyme Q(10), and alpha lipoic acid) and herbal preparations (feverfew, and butterbur). Although controversial, there are some reports demonstrating the benefit of recreational drugs such as marijuana, lysergic acid diethylamide and psilocybin in headache treatment. Behavioral treatments generally refer to cognitive behavioral therapy and biobehavioral training (biofeedback, relaxation training). Physical treatments in headache management are not as well defined but usually include acupuncture, oxygen therapy, transcutaneous electrical nerve stimulation, occlusal adjustment, cervical manipulation, physical therapy, massage, chiropractic therapy, and osteopathic manipulation. In this review, the available evidence for all these treatments will be discussed.

keywords:
Humans, Headache, Treatment Outcome, Complementary Therapies, Acupuncture Therapy, Hyperbaric Oxygenation, Behavior Therapy, Dietary Supplements, Physical Therapy Modalities

raw_json:
{"europe_pmc_id":"21352222","source":"MED","pub_type":null,"publisher":null,"importer":"Europe PMC"}


authors: Kometer M, Cahn BR, Andel D, Carter OL, Vollenweider FX.
publication_date: 2010-12-02
doi: 10.1016/j.biopsych.2010.10.002
pubmed_id: 21126732
source_url: https://doi.org/10.1016/j.biopsych.2010.10.002
substance_tags: psilocybin
topic_tags: Receptor Pharmacology,Consciousness
study_type: Other
source_name: Europe PMC
publication_status: published
date_added: 2026-07-01 06:54:14
last_checked: 2026-07-01 11:22:06
title:
The 5-HT2A/1A agonist psilocybin disrupts modal object completion associated with visual hallucinations.

abstract:
BackgroundRecent findings suggest that the serotonergic system and particularly the 5-HT2A/1A receptors are implicated in visual processing and possibly the pathophysiology of visual disturbances including hallucinations in schizophrenia and Parkinson's disease.MethodsTo investigate the role of 5-HT2A/1A receptors in visual processing the effect of the hallucinogenic 5-HT2A/1A agonist psilocybin (125 and 250 μg/kg vs. placebo) on the spatiotemporal dynamics of modal object completion was assessed in normal volunteers (n = 17) using visual evoked potential recordings in conjunction with topographic-mapping and source analysis. These effects were then considered in relation to the subjective intensity of psilocybin-induced visual hallucinations quantified by psychometric measurement.ResultsPsilocybin dose-dependently decreased the N170 and, in contrast, slightly enhanced the P1 component selectively over occipital electrode sites. The decrease of the N170 was most apparent during the processing of incomplete object figures. Moreover, during the time period of the N170, the overall reduction of the activation in the right extrastriate and posterior parietal areas correlated positively with the intensity of visual hallucinations.ConclusionsThese results suggest a central role of the 5-HT2A/1A-receptors in the modulation of visual processing. Specifically, a reduced N170 component was identified as potentially reflecting a key process of 5-HT2A/1A receptor-mediated visual hallucinations and aberrant modal object completion potential.

keywords:
Occipital Lobe, Visual Cortex, Humans, Parkinson Disease, Consciousness Disorders, Receptor, Serotonin, 5-HT1A, Receptor, Serotonin, 5-HT2A, Hallucinogens, Electroencephalography, Cluster Analysis, Photic Stimulation, Perceptual Closure, Reaction Time, Schizophrenia, Neuropsychological Tests, Psychometrics, Dose-Response Relationship, Drug, Adult, Female, Male, Serotonin Receptor Agonists, Psilocybin

raw_json:
{"europe_pmc_id":"21126732","source":"MED","pub_type":null,"publisher":null,"importer":"Europe PMC"}


publication_date: 2011-01-31
doi: 10.1523/jneurosci.4230-10.2011
pubmed_id: 21289196
source_url: https://doi.org/10.1523/jneurosci.4230-10.2011
substance_tags: psilocybin
topic_tags: Mechanism of Action,Receptor Pharmacology,Animal Study,Safety
study_type: Animal Study
source_name: Europe PMC
publication_status: published
date_added: 2026-07-01 06:54:14
last_checked: 2026-07-01 11:22:07
title:
Maternal influenza viral infection causes schizophrenia-like alterations of 5-HT₂A and mGlu₂ receptors in the adult offspring.

authors:
Moreno JL, Kurita M, Holloway T, López J, Cadagan R, Martínez-Sobrido L, García-Sastre A, González-Maeso J.

abstract:
Epidemiological studies indicate that maternal influenza viral infection increases the risk for schizophrenia in the adult offspring. The serotonin and glutamate systems are suspected in the etiology of schizophrenia, as well as in the mechanism of action of antipsychotic drugs. The effects of hallucinogens, such as psilocybin and mescaline, require the serotonin 5-HT(2A) receptor, and induce schizophrenia-like psychosis in humans. In addition, metabotropic glutamate receptor mGlu(2/3) agonists show promise as a new treatment for schizophrenia. Here, we investigated the level of expression and behavioral function of 5-HT(2A) and mGlu(2) receptors in a mouse model of maternal influenza viral infection. We show that spontaneous locomotor activity is diminished by maternal infection with the mouse-adapted influenza A/WSN/33 (H1N1) virus. The behavioral responses to hallucinogens and glutamate antipsychotics are both affected by maternal exposure to influenza virus, with increased head-twitch response to hallucinogens and diminished antipsychotic-like effect of the glutamate agonist. In frontal cortex of mice born to influenza virus-infected mothers, the 5-HT(2A) receptor is upregulated and the mGlu(2) receptor is downregulated, an alteration that may be involved in the behavioral changes observed. Additionally, we find that the cortical 5-HT(2A) receptor-dependent signaling pathways are significantly altered in the offspring of infected mothers, showing higher c-fos, egr-1, and egr-2 expression in response to the hallucinogenic drug DOI. Identifying a biochemical alteration that parallels the behavioral changes observed in a mouse model of prenatal viral infection may facilitate targeting therapies for treatment and prevention of schizophrenia.

keywords:
Cerebral Cortex, Frontal Lobe, Neural Pathways, Animals, Mice, Orthomyxoviridae Infections, Disease Models, Animal, Glutamic Acid, Proto-Oncogene Proteins c-fos, Receptors, Metabotropic Glutamate, Receptor, Serotonin, 5-HT2A, Antipsychotic Agents, Hallucinogens, Schizophrenia, Down-Regulation, Up-Regulation, Pregnancy, Maternal-Fetal Exchange, Female, Early Growth Response Protein 1, Early Growth Response Protein 2, Influenza A Virus, H1N1 Subtype

raw_json:
{"europe_pmc_id":"21289196","source":"MED","pub_type":null,"publisher":null,"importer":"Europe PMC"}


title: Absorption, distribution, metabolism and excretion pharmacogenomics of drugs of abuse.
authors: Meyer MR, Maurer HH.
publication_date: 2011-01-31
doi: 10.2217/pgs.10.171
pubmed_id: 21332315
source_url: https://doi.org/10.2217/pgs.10.171
substance_tags: psilocybin,psilocin
topic_tags: Addiction,Pharmacology,Safety,Drug Interactions,Genomics
study_type: Other
source_name: Europe PMC
publication_status: published
date_added: 2026-07-01 06:54:14
last_checked: 2026-07-01 11:22:06
abstract:
Pharmacologic and toxic effects of xenobiotics, such as drugs of abuse, depend on the genotype and phenotype of an individual, and conversely on the isoenzymes involved in their metabolism and transport. The current knowledge of such isoenzymes of frequently abused therapeutics such as opioids (oxycodone, hydrocodone, methadone, fentanyl, buprenorphine, tramadol, heroin, morphine and codeine), anesthetics (γ-hydroxybutyric acid, propofol, ketamine and phencyclidine) and cognitive enhancers (methylphenidate and modafinil), and some important plant-derived hallucinogens (lysergide, salvinorin A, psilocybin and psilocin), as well as of nicotine in humans are summarized in this article. The isoenzymes (e.g., cytochrome P450, glucuronyltransferases, esterases and reductases) involved in the metabolism of drugs and some pharmacokinetic data are discussed. The relevance of such data is discussed for predicting possible interactions with other xenobiotics, understanding pharmacokinetic behavior and pharmacogenomic variations, assessing toxic risks, developing suitable toxicological analysis procedures, and finally for interpretating drug testing results.

keywords:
Humans, Nicotine, Isoenzymes, Analgesics, Opioid, Hallucinogens, Nootropic Agents, Pharmacogenetics, Absorption, Tissue Distribution, Illicit Drugs

raw_json:
{"europe_pmc_id":"21332315","source":"MED","pub_type":null,"publisher":null,"importer":"Europe PMC"}


title: Pilot study of psilocybin treatment for anxiety in patients with advanced-stage cancer.
authors: Grob CS, Danforth AL, Chopra GS, Hagerty M, McKay CR, Halberstadt AL, Greer GR.
publication_date: 2010-09-05
doi: 10.1001/archgenpsychiatry.2010.116
pubmed_id: 20819978
source_url: https://doi.org/10.1001/archgenpsychiatry.2010.116
substance_tags: psilocybin
topic_tags: Depression,Anxiety,Aging,Personality Change,Safety,Adverse Events
study_type: Other
source_name: Europe PMC
publication_status: published
date_added: 2026-07-01 06:54:14
last_checked: 2026-07-01 11:22:06
abstract:
ContextResearchers conducted extensive investigations of hallucinogens in the 1950s and 1960s. By the early 1970s, however, political and cultural pressures forced the cessation of all projects. This investigation reexamines a potentially promising clinical application of hallucinogens in the treatment of anxiety reactive to advanced-stage cancer.ObjectiveTo explore the safety and efficacy of psilocybin in patients with advanced-stage cancer and reactive anxiety.DesignA double-blind, placebo-controlled study of patients with advanced-stage cancer and anxiety, with subjects acting as their own control, using a moderate dose (0.2 mg/kg) of psilocybin.SettingA clinical research unit within a large public sector academic medical center.ParticipantsTwelve adults with advanced-stage cancer and anxiety.Main outcome measuresIn addition to monitoring safety and subjective experience before and during experimental treatment sessions, follow-up data including results from the Beck Depression Inventory, Profile of Mood States, and State-Trait Anxiety Inventory were collected unblinded for 6 months after treatment.ResultsSafe physiological and psychological responses were documented during treatment sessions. There were no clinically significant adverse events with psilocybin. The State-Trait Anxiety Inventory trait anxiety subscale demonstrated a significant reduction in anxiety at 1 and 3 months after treatment. The Beck Depression Inventory revealed an improvement of mood that reached significance at 6 months; the Profile of Mood States identified mood improvement after treatment with psilocybin that approached but did not reach significance.ConclusionsThis study established the feasibility and safety of administering moderate doses of psilocybin to patients with advanced-stage cancer and anxiety. Some of the data revealed a positive trend toward improved mood and anxiety. These results support the need for more research in this long-neglected field.Trial registrationclinicaltrials.gov Identifier: NCT00302744.

keywords:
Humans, Neoplasms, Hallucinogens, Neoplasm Staging, Treatment Outcome, Follow-Up Studies, Pilot Projects, Double-Blind Method, Affect, Anxiety, Personality Inventory, Time Factors, Adult, Middle Aged, Female, Male, Psilocybin

raw_json:
{"europe_pmc_id":"20819978","source":"MED","pub_type":null,"publisher":null,"importer":"Europe PMC"}


authors: Riley S, Thompson J, Griffin C.
publication_date: 2010-10-31
doi: 10.1016/j.drugpo.2010.07.001
pubmed_id: 20810266
source_url: https://doi.org/10.1016/j.drugpo.2010.07.001
substance_tags: psilocybin,psilocin
topic_tags: Aging,Spirituality,Adolescents,Safety
study_type: Other
source_name: Europe PMC
publication_status: published
date_added: 2026-07-01 06:54:14
last_checked: 2026-07-01 11:22:07
title:
Turn on, tune in, but don't drop out: The impact of neo-liberalism on magic mushroom users' (in)ability to imagine collectivist social worlds.

abstract:
BackgroundBetween 2002 and 2005 fresh or unprepared psilocin-based 'magic' mushrooms were legal to possess and traffic in the UK, and commercial sales demonstrated a significant market for this hallucinogenic drug. During and after this time there has been relatively little analysis concerning how magic mushroom users accounted for their drug use, nor on the wider political and cultural discourses that might have shaped this sense making.MethodIn this paper we present a critical analysis of contemporary discourses around magic mushroom use in the UK through a multi-level discourse analysis of focus group data from 20 magic mushroom users (13 male and 7 female, mean age 25 years), taken at a time when magic mushrooms were being legally sold in the UK.ResultsLocating participants' use of magic mushrooms within the context of a culture of intoxication, neo-liberalism and the legacy of 1960s psychedelic philosophy, we identify six interpretative repertoires in their talk, which were subsumed within two overarching discourses. The first discourse drew on neo-liberal rhetoric, constructing participants as rational risk managing subjects engaged in a form of calculated hedonism that was legitimated as an act of personal freedom and consumer choice. The second discourse, identified as 'post-psychedelic', both celebrated and problematised a collective, connected 'hippy' form of spirituality.ConclusionThe paper analyses the relationships between identity, consumption and citizenship by arguing that people's ability to imagine collectivist, spiritual or interconnected social worlds has been contained within neo-liberalism rhetoric.

keywords:
Humans, Substance-Related Disorders, Hallucinogens, Focus Groups, Spirituality, Politics, Philosophy, Adolescent, Adult, Female, Male, Psilocybe, Young Adult, United Kingdom, Psilocybin

raw_json:
{"europe_pmc_id":"20810266","source":"MED","pub_type":null,"publisher":null,"importer":"Europe PMC"}


title: The neurobiology of psychedelic drugs: implications for the treatment of mood disorders.
authors: Vollenweider FX, Kometer M.
publication_date: 2010-08-17
doi: 10.1038/nrn2884
pubmed_id: 20717121
source_url: https://doi.org/10.1038/nrn2884
keywords: Brain, Animals, Humans, Hallucinogens, Mood Disorders, Models, Neurological
substance_tags: psilocybin
topic_tags: Neuroplasticity,Brain Imaging,Mechanism of Action,Aging
study_type: Other
source_name: Europe PMC
publication_status: published
date_added: 2026-07-01 06:54:14
last_checked: 2026-07-01 11:22:07
abstract:
After a pause of nearly 40 years in research into the effects of psychedelic drugs, recent advances in our understanding of the neurobiology of psychedelics, such as lysergic acid diethylamide (LSD), psilocybin and ketamine have led to renewed interest in the clinical potential of psychedelics in the treatment of various psychiatric disorders. Recent behavioural and neuroimaging data show that psychedelics modulate neural circuits that have been implicated in mood and affective disorders, and can reduce the clinical symptoms of these disorders. These findings raise the possibility that research into psychedelics might identify novel therapeutic mechanisms and approaches that are based on glutamate-driven neuroplasticity.

raw_json:
{"europe_pmc_id":"20717121","source":"MED","pub_type":null,"publisher":null,"importer":"Europe PMC"}


title: Psychometric evaluation of the altered states of consciousness rating scale (OAV).
authors: Studerus E, Gamma A, Vollenweider FX.
publication_date: 2010-08-30
doi: 10.1371/journal.pone.0012412
pubmed_id: 20824211
source_url: https://doi.org/10.1371/journal.pone.0012412
substance_tags: psilocybin
topic_tags: Consciousness,Observational Study
study_type: Observational Study
source_name: Europe PMC
publication_status: published
date_added: 2026-07-01 06:54:14
last_checked: 2026-07-01 11:22:07
abstract:
BackgroundThe OAV questionnaire has been developed to integrate research on altered states of consciousness (ASC). It measures three primary and one secondary dimensions of ASC that are hypothesized to be invariant across ASC induction methods. The OAV rating scale has been in use for more than 20 years and applied internationally in a broad range of research fields, yet its factorial structure has never been tested by structural equation modeling techniques and its psychometric properties have never been examined in large samples of experimentally induced ASC.Methodology/principal findingsThe present study conducted a psychometric evaluation of the OAV in a sample of psilocybin (n = 327), ketamine (n = 162), and MDMA (n = 102) induced ASC that was obtained by pooling data from 43 experimental studies. The factorial structure was examined by confirmatory factor analysis, exploratory structural equation modeling, hierarchical item clustering (ICLUST), and multiple indicators multiple causes (MIMIC) modeling. The originally proposed model did not fit the data well even if zero-constraints on non-target factor loadings and residual correlations were relaxed. Furthermore, ICLUST suggested that the "oceanic boundlessness" and "visionary restructuralization" factors could be combined on a high level of the construct hierarchy. However, because these factors were multidimensional, we extracted and examined 11 new lower order factors. MIMIC modeling indicated that these factors were highly measurement invariant across drugs, settings, questionnaire versions, and sexes. The new factors were also demonstrated to have improved homogeneities, satisfactory reliabilities, discriminant and convergent validities, and to differentiate well among the three drug groups.Conclusions/significanceThe original scales of the OAV were shown to be multidimensional constructs. Eleven new lower order scales were constructed and demonstrated to have desirable psychometric properties. The new lower order scales are most likely better suited to assess drug induced ASC.

keywords:
Humans, N-Methyl-3,4-methylenedioxyamphetamine, Ketamine, Cluster Analysis, Reproducibility of Results, Consciousness, Psychometrics, Models, Theoretical, Adult, Female, Male, Surveys and Questionnaires, Psilocybin

raw_json:
{"europe_pmc_id":"20824211","source":"MED","pub_type":null,"publisher":null,"importer":"Europe PMC"}


title: Determining the subjective effects of TFMPP in human males.
authors: Jan RK, Lin JC, Lee H, Sheridan JL, Kydd RR, Kirk IJ, Russell BR.
publication_date: 2010-06-15
doi: 10.1007/s00213-010-1911-y
pubmed_id: 20552171
source_url: https://doi.org/10.1007/s00213-010-1911-y
substance_tags: psilocybin
topic_tags: Anxiety,Addiction,Receptor Pharmacology,Observational Study
study_type: Observational Study
source_name: Europe PMC
publication_status: published
date_added: 2026-07-01 06:54:14
last_checked: 2026-07-01 11:22:07
abstract:
RationaleTrifluoromethylphenyl piperazine (TFMPP) is an active constituent of a relatively new group of recreational drugs known as 'party pills'. TFMPP has been anecdotally reported to induce mild psychedelic effects similar to lysergic acid diethylamide and psilocybin. There has been no research about the subjective effects of TFMPP in humans.ObjectivesThis study aimed to investigate the subjective effects of TFMPP in human males.MethodsA randomised, double-blind, placebo-controlled trial design was used to investigate the subjective effects of TFMPP in 30 healthy, non-smoking male volunteers (mean age 24 +/- 4 years). Participants were randomised into two groups and given either TFMPP 60 mg (n = 15) or placebo (n = 15). Each participant completed three rating scales, the Addiction Research Centre Inventory (ARCI), the Profile of Mood States (POMS) and the Visual Analogue Scales (VAS), both before and 120 min after drug administration.ResultsResults from the ARCI indicated that TFMPP produced increases in 'dysphoria' and 'dexamphetamine-like effects'. TFMPP also increased ratings of 'tension/anxiety' and 'confusion/bewilderment' as rated on the POMS. Results from the VAS indicated increases in 'drug liking', 'high' and 'stimulated' ratings relevant to placebo.ConclusionsIncreased ratings of 'dexamphetamine-like effects', 'tension/anxiety', 'stimulated' and 'high' following TFMPP administration resemble the subjective effects of common amphetamine-type stimulants. However, increases in 'dysphoria' and 'confusion/bewilderment' ratings following TFMPP are more commonly associated with drugs that have greater effects on serotonin release, binding and reuptake such as 1-[3-chlorophenyl]-piperazine, fenfluramine and lysergic acid diethylamide.

keywords:
Humans, Piperazines, Hallucinogens, Affect, Adult, Male, Serotonin Receptor Agonists, Surveys and Questionnaires, Illicit Drugs

raw_json:
{"europe_pmc_id":"20552171","source":"MED","pub_type":null,"publisher":null,"importer":"Europe PMC"}


authors: Butelman ER, Rus S, Prisinzano TE, Kreek MJ.
publication_date: 2010-01-18
doi: 10.1007/s00213-009-1771-5
pubmed_id: 20084367
source_url: https://doi.org/10.1007/s00213-009-1771-5
substance_tags: psilocybin
topic_tags: Addiction,Receptor Pharmacology
study_type: Other
source_name: Europe PMC
publication_status: published
date_added: 2026-07-01 06:54:14
last_checked: 2026-07-01 11:22:07
title:
The discriminative effects of the kappa-opioid hallucinogen salvinorin A in nonhuman primates: dissociation from classic hallucinogen effects.

abstract:
RationaleThe widely available hallucinogen salvinorin A is a unique example of a plant-derived compound selective for kappa-opioid receptors and may produce effects distinct from those of other compounds with classic hallucinogenic or dissociative properties which are also abused in humans.ObjectivesThe objective of this study is to characterize the salvinorin A discriminative cue in nonhuman primates with high kappa-receptor genetic homology to humans.MethodsAdult rhesus monkeys (n = 3) were trained to discriminate salvinorin A (0.015 mg/kg, s.c.) from vehicle, in a food-reinforced operant discrimination assay. Parallel studies, using unconditioned behavioral endpoints (facial relaxation and ptosis) also evaluated the kappa-opioid receptor mediation of salvinorin A in vivo function.ResultsMonkeys trained to discriminate salvinorin A generalized structurally diverse, centrally penetrating kappa-agonists (bremazocine, U69,593, and U50,488). By contrast, mu- and delta-opioid agonists (fentanyl and SNC80, respectively) were not generalized, nor were the serotonergic 5HT2 hallucinogen psilocybin or the dissociative N-methyl-D-aspartic acid antagonist, ketamine. The discriminative effects of salvinorin A were blocked by the opioid antagonist quadazocine (0.32 mg/kg), but not by the 5HT2 antagonist ketanserin (0.1 mg/kg). Consistent with these findings, salvinorin and kappa-agonists (e.g., U69,593) produce effects in the unconditioned endpoints (e.g., ptosis), whereas psilocybin was inactive.ConclusionsThese findings support the conclusion that the interoceptive/discriminative cue produced by salvinorin A is mediated by agonism at kappa-receptors and is mechanistically distinct from that produced by a classic serotonergic hallucinogen.

keywords:
Animals, Macaca mulatta, Diterpenes, Clerodane, Receptors, Opioid, delta, Receptors, Opioid, kappa, Receptors, Opioid, mu, Hallucinogens, Conditioning, Operant, Dose-Response Relationship, Drug, Male, Discrimination, Psychological

raw_json:
{"europe_pmc_id":"20084367","source":"MED","pub_type":null,"publisher":null,"importer":"Europe PMC"}


title: Timothy Leary, Richard Alpert (Ram Dass) and the changing definition of psilocybin.
authors: Wark C, Galliher JF.
publication_date: 2009-09-08
doi: 10.1016/j.drugpo.2009.08.004
pubmed_id: 19744846
source_url: https://doi.org/10.1016/j.drugpo.2009.08.004
substance_tags: psilocybin
topic_tags: Adolescents
study_type: Other
source_name: Europe PMC
publication_status: published
date_added: 2026-07-01 06:54:14
last_checked: 2026-07-01 11:22:06
abstract:
BackgroundThis research focuses on the events leading to the 1968 U.S. federal prohibition of psilocybin. It is a study of duelling moral entrepreneurs-Timothy Leary and Richard Alpert vs. the Harvard University Administration. The goal is to show how the primary active compound in an ostensibly harmless fungus (the psilocybin mushroom) became controversial in less than a decade.MethodsWe used books, newspapers, magazine articles and previously unpublished materials (including documents from the Harvard Archives) to analyze Leary and Alpert's lives and careers through the early 1970s.ResultsThe prohibition of psilocybin in the U.S. was largely a product of Leary and Alpert's involvement in the "Harvard drug scandal" and their transformation from Harvard professors to countercultural icons. They tested the substance on a variety of human subjects and in doing so piqued the interest of Harvard undergraduates while drawing condemnation from other faculty and Harvard administrators. This case is theoretically interesting because unlike most illegal drugs, psilocybin was never linked to a threatening minority group, but to some of the nation's most privileged youth.ConclusionThe Harvard administrators were not really moral entrepreneurs but Leary and Alpert clearly were. Although they were far from being prohibitionists, they were self-righteous crusaders on different but equally holy missions for the good of young and minority Americans. Ironically, due to their successes the possession of psilocybin was criminalized under United States federal law in 1968 (Pub. L. No. 90-639, Stat. 1361 1968 and Boire, 2002). This case study demonstrates that crusaders can be successful in changing culture even when laws are passed in futile attempts to control their behaviour, just as Leary predicted.

keywords:
Humans, Hallucinogens, Psychology, Drug and Narcotic Control, History, 20th Century, United States, Psilocybin

raw_json:
{"europe_pmc_id":"19744846","source":"MED","pub_type":null,"publisher":null,"importer":"Europe PMC"}


title: Glucuronidation of psilocin and 4-hydroxyindole by the human UDP-glucuronosyltransferases.
authors: Manevski N, Kurkela M, Höglund C, Mauriala T, Court MH, Yli-Kauhaluoma J, Finel M.
publication_date: 2009-12-09
doi: 10.1124/dmd.109.031138
pubmed_id: 20007669
source_url: https://doi.org/10.1124/dmd.109.031138
substance_tags: psilocybin,psilocin
topic_tags: Clinical Trial
study_type: Clinical Trial
source_name: Europe PMC
publication_status: published
date_added: 2026-07-01 06:54:14
last_checked: 2026-07-01 11:22:05
abstract:
We have examined the glucuronidation of psilocin, a hallucinogenic indole alkaloid, by the 19 recombinant human UDP-glucuronosyltransferases (UGTs) of subfamilies 1A, 2A, and 2B. The glucuronidation of 4-hydroxyindole, a related indole that lacks the N,N-dimethylaminoethyl side chain, was studied as well. UGT1A10 exhibited the highest psilocin glucuronidation activity, whereas the activities of UGTs 1A9, 1A8, 1A7, and 1A6 were significantly lower. On the other hand, UGT1A6 was by far the most active enzyme mediating 4-hydroxyindole glucuronidation, whereas the activities of UGTs 1A7-1A10 toward 4-hydroxyindole resembled their respective psilocin glucuronidation rates. Psilocin glucuronidation by UGT1A10 followed Michaelis-Menten kinetics in which psilocin is a low-affinity high-turnover substrate (K(m) = 3.8 mM; V(max) = 2.5 nmol/min/mg). The kinetics of psilocin glucuronidation by UGT1A9 was more complex and may be best described by biphasic kinetics with both intermediate (K(m1) = 1.0 mM) and very low affinity components. The glucuronidation of 4-hydroxyindole by UGT1A6 exhibited higher affinity (K(m) = 178 microM) and strong substrate inhibition. Experiments with human liver and intestinal microsomes (HLM and HIM, respectively) revealed similar psilocin glucuronidation activity in both samples, but a much higher 4-hydroxyindole glucuronidation rate was found in HLM versus HIM. The expression levels of UGTs 1A6-1A10 in different tissues were studied by quantitative real-time-PCR, and the results, together with the activity assays findings, suggest that whereas psilocin may be subjected to extensive glucuronidation by UGT1A10 in the small intestine, UGT1A9 is likely the main contributor to its glucuronidation once it has been absorbed into the circulation.

keywords:
Liver, Microsomes, Humans, Glucuronides, Indoles, Isoenzymes, Glucuronosyltransferase, Recombinant Proteins, RNA, Messenger, Hallucinogens, Sulfhydryl Reagents, Reverse Transcriptase Polymerase Chain Reaction, Organ Specificity, Substrate Specificity, Kinetics, Metabolic Detoxication, Phase II, Psilocybin, UDP-Glucuronosyltransferase 1A9

raw_json:
{"europe_pmc_id":"20007669","source":"MED","pub_type":null,"publisher":null,"importer":"Europe PMC"}


authors: Laussmann T, Meier-Giebing S.
publication_date: 2010-01-03
doi: 10.1016/j.forsciint.2009.12.013
pubmed_id: 20047807
source_url: https://doi.org/10.1016/j.forsciint.2009.12.013
substance_tags: psilocybin,psilocin
topic_tags: Toxicity
study_type: Other
source_name: Europe PMC
publication_status: published
date_added: 2026-07-01 06:54:14
last_checked: 2026-07-01 11:22:06
title:
Forensic analysis of hallucinogenic mushrooms and khat (Catha edulis Forsk) using cation-exchange liquid chromatography.

abstract:
Hallucinogenic mushrooms (e.g. Psilocybe and Panaeolus species) as well as leaves and young shoots of the khat tree (Catha edulis Forsk) are illicit drugs in many countries. The exact concentration of the hallucinogenic alkaloids psilocin and psilocybin in mushrooms and the sympathomimetic alkaloids cathinone and cathine in khat is usually essential for jurisdiction. Facing an increasing number of mushroom and khat seizures by German customs authorities, a convenient comprehensive quantitative HPLC method based on cation-exchange liquid chromatography for these rather "exotic" drugs has been developed which avoids time-consuming multi-step sample preparation or chemical derivatization procedures. Using this method a number of different hallucinogenic fungi species and products that are mainly distributed via the internet have been analysed (dried and fresh Psilocybe cubensis Singer as well as P. cubensis collected from "grow boxes", Panaeolus cyanescens Berkeley and Broome and so-called "philosopher stones" (sclerotia of Psilocybe species)). Highest total amounts of psilocin have been detected in dried P. cyanescens reaching up to 3.00+/-0.24 mg per 100 mg. The distribution of khat alkaloids in different parts of the khat shoots has been studied. High concentrations of cathinone have not only been detected in leaves but also in green parts and barks of stalks. Additionally, the sample treatment for fresh mushroom and khat samples has been optimised. Highest amounts of alkaloids were found when fresh material was freeze-dried.

keywords:
Agaricales, Catha, Phenylpropanolamine, Alkaloids, Central Nervous System Stimulants, Hallucinogens, Freeze Drying, Chromatography, Liquid, Desiccation, Forensic Toxicology, Plant Structures, Limit of Detection, Psilocybin, Illicit Drugs

raw_json:
{"europe_pmc_id":"20047807","source":"MED","pub_type":null,"publisher":null,"importer":"Europe PMC"}


authors: Koçak A, De Cotiis LM, Hoffman DB.
publication_date: 2009-12-05
doi: 10.1016/j.forsciint.2009.11.002
pubmed_id: 19969433
source_url: https://doi.org/10.1016/j.forsciint.2009.11.002
substance_tags: psilocybin,psilocin
topic_tags: Toxicity
study_type: Qualitative Study
source_name: Europe PMC
publication_status: published
date_added: 2026-07-01 06:54:14
last_checked: 2026-07-01 11:22:06
title:
Comparative study of ATR and transflection IR spectroscopic techniques for the analysis of hallucinogenic mushrooms.

abstract:
This paper compares the use of ATR and transflection spectroscopic techniques for the qualitative analysis of psilocin extracted from hallucinogenic mushrooms and control spiked mushrooms. Both techniques gave comparable results and agreed with prior GC/MS analysis of the actual case samples.

keywords:
Agaricales, Hallucinogens, Spectrophotometry, Infrared, Gas Chromatography-Mass Spectrometry, Forensic Toxicology, Psilocybin

raw_json:
{"europe_pmc_id":"19969433","source":"MED","pub_type":null,"publisher":null,"importer":"Europe PMC"}


title: [Student's use of illicit drugs: a survey in a preventive health service].
authors: Morvan Y, Rouvier J, Olié JP, Lôo H, Krebs MO.
publication_date: 2009-11-30
doi: 10.1016/s0013-7006(09)73471-2
pubmed_id: 20141772
source_url: https://doi.org/10.1016/s0013-7006(09)73471-2
substance_tags: psilocybin
topic_tags: Anxiety,Addiction,Personality Change,Observational Study,Adolescents
study_type: Observational Study
source_name: Europe PMC
publication_status: published
date_added: 2026-07-01 06:54:14
last_checked: 2026-07-01 11:22:07
abstract:
IntroductionThe use of illicit drugs by students and the possible psychological repercussions in this population of young adults is an important public health issue. While some data in the literature suggest a relationship between cannabis and the occurrence of mental health disorders, and in particular psychotic illnesses, epidemiologic surveys have shown that cannabis is the most consumed illicit drug in France.Aim of the studyTo carry out a quantitative and qualitative epidemiological investigation of substance use within a student population seen during their mandatory preventive health visit at the University medical facility.MethodStudents were asked to take part in an investigation of their substance consumption and their individual experiences with cannabis in particular. Personality autoquestionnaires were performed and the psychotomimetic effects of cannabis were investigated with substance use within a student population seen during their mandatory preventive health visit at the University medical facility.ResultsA total of 3,807 students took part in the survey with a response rate of approximately 50%. Preliminary results relating to a subsample of this study are presented here (n = 880, mean age 20 years, 65% women). 44% of the students consumed cannabis at least once in their life. The prevalence of regular consumption in students (at least once a week) was of 18%, 11% had periods of daily or close to daily consumptions, and 13% used cannabis in the last month. For each of the drugs cocaine, ecstasy (MDMA), and mushrooms (psilocybin) the prevalence of experimentation (at least once) was 5% for cocaine, 4% for ecstasy and mushrooms, and for LSD the rate was 1,5%. Other evaluated substances had a prevalence of consumption lower than 1%. For the first cannabis consumptions, a majority of students state to felt "pleasant" effects: relaxation (71%) and euphoria (53%). 13% state to have felt effects of anxiety or sadness. 25% admit having had difficulties of expression, 24% memory deficits, 35% trouble with coordination or balance and 39% difficulties of concentration. Approximately 16% had impressions of depersonalization and derealization. Lastly, some experienced "psychotic-like" effects such as visual (10%) and auditory (6%) hallucinations, as well as referential ideas (16%), mistrust or feelings of persecution (11%). 26% of the student sample had felt at least one of these last four "psychotic-like" effects.DiscussionThe results are consistent with the idea that the impact of cannabis consumption is highly variable among different consumers. Implications for prevention strategies are discussed such as educational interventions based on recognition and motivation for change.

keywords:
Humans, Substance-Related Disorders, Marijuana Abuse, Psychotropic Drugs, Health Surveys, Motivation, Adolescent, Preventive Health Services, Student Health Services, France, Female, Male, Young Adult, Surveys and Questionnaires, Illicit Drugs

raw_json:
{"europe_pmc_id":"20141772","source":"MED","pub_type":null,"publisher":null,"importer":"Europe PMC"}


authors: Kovacic P, Somanathan R.
publication_date: 2009-08-31
doi: 10.4161/oxim.2.4.9380
pubmed_id: 20716904
source_url: https://doi.org/10.4161/oxim.2.4.9380
substance_tags: psilocybin,psilocin
topic_tags: Neuroplasticity,Mechanism of Action,Receptor Pharmacology,Epigenetics
study_type: Other
source_name: Europe PMC
publication_status: published
date_added: 2026-07-01 06:54:14
last_checked: 2026-07-01 11:22:06
title:
Novel, unifying mechanism for mescaline in the central nervous system: electrochemistry, catechol redox metabolite, receptor, cell signaling and structure activity relationships.

abstract:
A unifying mechanism for abused drugs has been proposed previously from the standpoint of electron transfer. Mescaline can be accommodated within the theoretical framework based on redox cycling by the catechol metabolite with its quinone counterpart. Electron transfer may play a role in electrical effects involving the nervous system in the brain. This approach is in accord with structure activity relationships involving mescaline, abused drugs, catecholamines, and etoposide. Inefficient demethylation is in keeping with the various drug properties, such as requirement for high dosage and slow acting. There is a discussion of receptor binding, electrical effects, cell signaling and other modes of action. Mescaline is a nonselective, seretonin receptor agonist. 5-HTP receptors are involved in the stimulus properties. Research addresses the aspect of stereochemical requirements. Receptor binding may involve the proposed quinone metabolite and/or the amino sidechain via protonation. Electroencephalographic studies were performed on the effects of mescaline on men. Spikes are elicited by stimulation of a cortical area. The potentials likely originate in nonsynaptic dendritic membranes. Receptor-mediated signaling pathways were examined which affect mescaline behavior. The hallucinogen belongs to the class of 2AR agonists which regulate pathways in cortical neurons. The research identifies neural and signaling mechanisms responsible for the biological effects. Recently, another hallucinogen, psilocybin, has been included within the unifying mechanistic framework. This mushroom constituent is hydrolyzed to the phenol psilocin, also active, which is subsequently oxidized to an ET o-quinone or iminoquinone.

keywords:
Central Nervous System, Mescaline, Catechols, Quinones, Receptors, Serotonin, Signal Transduction, Protein Binding, Structure-Activity Relationship, Electron Transport, Oxidation-Reduction, Serotonin Receptor Agonists

raw_json:
{"europe_pmc_id":"20716904","source":"MED","pub_type":null,"publisher":null,"importer":"Europe PMC"}


title: Availability of websites offering to sell psilocybin spores and psilocybin.
authors: Lott JP, Marlowe DB, Forman RF.
publication_date: 2009-08-31
doi: 10.1080/02791072.2009.10400541
pubmed_id: 19999684
source_url: https://doi.org/10.1080/02791072.2009.10400541
keywords: Humans, Spores, Fungal, Substance-Related Disorders, Hallucinogens, Internet, Psilocybe, Psilocybin
substance_tags: psilocybin
topic_tags: General
study_type: Other
source_name: Europe PMC
publication_status: published
date_added: 2026-07-01 06:54:14
last_checked: 2026-07-01 11:22:05
abstract:
This study assesses the availability of websites offering to sell psilocybin spores and psilocybin, a powerful hallucinogen contained in Psilocybe mushrooms. Over a 25-month period beginning in March 2003, eight searches were conducted in Google using the term "psilocybin spores." In each search the first 100 nonsponsored links obtained were scored by two independent raters according to standardized criteria to determine whether they offered to sell psilocybin or psilocybin spores. No attempts were made to procure the products offered for sale in order to ascertain whether the marketed psilocybin was in fact "genuine" or "counterfeit." Of the 800 links examined, 58% led to websites offering to sell psilocybin spores. Additionally, evidence that whole Psilocybe mushrooms are offered for sale online was obtained. Psilocybin and psilocybin spores were found to be widely available for sale over the Internet. Online purchase of psilocybin may facilitate illicit use of this potent psychoactive substance. Additional studies are needed to assess whether websites offering to sell psilocybin and psilocybin spores actually deliver their products as advertised.

raw_json:
{"europe_pmc_id":"19999684","source":"MED","pub_type":null,"publisher":null,"importer":"Europe PMC"}


title: Effects of Psilocybe argentipes on marble-burying behavior in mice.
authors: Matsushima Y, Shirota O, Kikura-Hanajiri R, Goda Y, Eguchi F.
publication_date: 2009-08-06
doi: 10.1271/bbb.90095
pubmed_id: 19661714
source_url: https://doi.org/10.1271/bbb.90095
substance_tags: psilocybin
topic_tags: OCD,Animal Study
study_type: Animal Study
source_name: Europe PMC
publication_status: published
date_added: 2026-07-01 06:54:14
last_checked: 2026-07-01 11:22:07
abstract:
Psilocybe argentipes is a hallucinogenic mushroom. The present study examined the effects of P. argentipes on marble-burying behavior, which is considered an animal model of obsessive-compulsive disorder. P. argentipes significantly inhibited marble-burying behavior without affecting locomotor activity as compared with the same dose of authentic psilocybin. These findings suggest that P. argentipes would be efficient in clinical obsessive-compulsive disorder therapy.

keywords:
Animals, Mice, Inbred ICR, Mice, Calcium Carbonate, Fluvoxamine, Tryptophan, Antipsychotic Agents, Hallucinogens, Behavior, Animal, Motor Activity, Male, Psilocybe

raw_json:
{"europe_pmc_id":"19661714","source":"MED","pub_type":null,"publisher":null,"importer":"Europe PMC"}


authors: Björnstad K, Hultén P, Beck O, Helander A.
publication_date: 2009-06-30
doi: 10.1080/15563650903037181
pubmed_id: 19586355
source_url: https://doi.org/10.1080/15563650903037181
substance_tags: psilocin
topic_tags: Adolescents,Toxicity
study_type: Other
source_name: Europe PMC
publication_status: published
date_added: 2026-07-01 06:54:14
last_checked: 2026-07-01 11:22:07
title:
Bioanalytical and clinical evaluation of 103 suspected cases of intoxications with psychoactive plant materials.

abstract:
IntroductionProblems associated with the increasing abuse of plant-derived psychoactive substances have recently attracted attention. This study involved bioanalytical and clinical examinations of intoxication cases suspected to be linked to such plant materials.MethodsUrine samples were collected at emergency wards in Sweden from patients who either admitted or were suspected of ingestion of psychoactive plant materials. The bioanalytical investigation employed a liquid chromatography-tandem mass spectrometry multicomponent method covering 10 plant-derived substances (atropine, dimethyltryptamine, ephedrine, harmaline, harmine, ibogaine, lysergic acid amide, psilocin, scopolamine, and yohimbine) and a gas chromatography-mass spectrometry method for asarone. Routine testing for illicit drugs was also performed.ResultsOver a 4-year period, 103 urine samples collected from mainly young people (age range 13-52 years, median 19) were studied. Among 53 cases where ingestion of any of the 11 plant-derived substances covered in this study was admitted or suspected, 41 (77%) could be confirmed bioanalytically. Nine of the 11 substances tested for were detected, the exceptions being ibogaine and yohimbine. Psilocin, originating from ingestion of hallucinogenic mushrooms, was the most frequent drug accounting for 54% of the cases. The most common means of drug acquisition (56%) was purchase over the Internet.ConclusionThe patients using psychoactive plant materials were mainly young and commonly used the Internet for drug acquisition. Having access to bioanalytical methods for detection of plant-derived psychoactives is therefore considered important, when providing clinical toxicology service.

keywords:
Humans, Plants, Toxic, Poisoning, Hallucinogens, Psychotropic Drugs, Plant Extracts, Chromatography, High Pressure Liquid, Spectrometry, Mass, Electrospray Ionization, Adolescent, Adult, Middle Aged, Emergency Service, Hospital, Female, Male, Tandem Mass Spectrometry, Young Adult

raw_json:
{"europe_pmc_id":"19586355","source":"MED","pub_type":null,"publisher":null,"importer":"Europe PMC"}


authors: Kawamura M, Kikura-Hanajiri R, Goda Y.
publication_date: 2009-05-31
doi: 10.1248/yakushi.129.719
pubmed_id: 19483414
source_url: https://doi.org/10.1248/yakushi.129.719
substance_tags: psilocybin,psilocin
topic_tags: Addiction
study_type: Other
source_name: Europe PMC
publication_status: published
date_added: 2026-07-01 06:54:14
last_checked: 2026-07-01 11:22:07
title:
[Simple and rapid screening for psychotropic natural products using Direct Analysis in Real Time (DART)-TOFMS].

abstract:
Direct Analysis in Real Time (DART) is a novel ionization technique that provides for the rapid ionization of small molecules under ambient conditions. To investigate the trend of non-controlled psychotropic plants of abuse in Japan, a rapid screening method, without sample preparation, was developed using DART-time of flight mass spectrometer (TOFMS) for plant products. The major psychotropic constituents of these products were determined using liquid chromatography-mass spectrometry (LC/MS). As a result of the DART-TOFMS analyses of 36 products, the protonated molecular ions [M+H](+), corresponding to 6 kinds of major hallucinogenic constituents (mescaline, salvinorin A, N,N-dimethyltryptamine, harmine, harmaline and lysergamide), were detected in 21 products. It was possible to estimate their accurate elemental compositions through exact mass measurements. These results were consistent with those of the LC/MS analyses and the contents of the 6 psychotropic constituents were in the range from 0.05 to 45 microg/mg. Typical controlled narcotic drugs, tetrahydrocannabinol, opioid alkaloids and psilocin were also directly detected in marijuana cigarette, opium gum and magic mushroom respectively. Although it is difficult to estimate the matrix effects caused by other plant ingredients, the DART-TOFMS could be useful as a simple and rapid screening method for the targeted psychotropic natural products, because it provides the molecular information of the target compounds without time-consuming extraction and pre-treatment steps.

keywords:
Plants, Medicinal, Psychotropic Drugs, Biological Products, Chromatography, Liquid, Substance Abuse Detection, Legislation, Drug, Japan, Mass Spectrometry

raw_json:
{"europe_pmc_id":"19483414","source":"MED","pub_type":null,"publisher":null,"importer":"Europe PMC"}


title: Analysis of mushroom exposures in Texas requiring hospitalization, 2005-2006.
authors: Barbee G, Berry-Cabán C, Barry J, Borys D, Ward J, Salyer S.
publication_date: 2009-05-31
doi: 10.1007/bf03161087
pubmed_id: 19415588
source_url: https://doi.org/10.1007/bf03161087
substance_tags: psilocybin
topic_tags: Chronic Pain,Review Article,Adolescents
study_type: Review Article
source_name: Europe PMC
publication_status: published
date_added: 2026-07-01 06:54:14
last_checked: 2026-07-01 11:22:07
abstract:
IntroductionTexas has approximately 200 species of wild mushrooms, including toxic and hallucinogenic varieties. Mushroom ingestions in Texas were studied for 2005-2006.MethodsData was obtained via Texas Poison Control Centers and retrospectively reviewed. Case notes were reviewed individually regarding initial reporting, age, signs and symptoms, toxic effect, management, and patient outcomes.ResultsA total of 742 exposures occurred during the study period. All exposures were acute and intentional. Of these exposures, 59 (7.9%) were admitted to the hospital, with 17 (28.8% of admissions) requiring admission to a critical care unit. Four cases required inpatient psychiatric admission. The average age of admitted exposures was 20.5 years, with a male-to-female predominance of 3.3:1. Eleven (22.9%) of the admitted exposures were identified, with Psilocybin being the most common agent (n = 10, 91%). Among the admissions, co-ingestions were identified with the mushroom ingestion in eleven patients (40.7%). The most common symptoms in admitted patients were vomiting (n = 34, 57.6%), nausea (n = 19, 32.2%), altered mental status (n = 17, 28.8%), abdominal pain (n = 13, 22%), and diarrhea (n = 10, 16.9%).ConclusionsAll mushroom exposures examined were acute and intentional. Major toxic reactions were uncommon, and no deaths were reported. Serious poisoning from mushroom ingestion is rare in Texas; however, there is greater need for information dissemination on morbidity.

keywords:
Humans, Mushroom Poisoning, Acute Disease, Abdominal Pain, Diarrhea, Nausea, Vomiting, Hallucinogens, Hospitalization, Retrospective Studies, Mental Disorders, Adolescent, Adult, Aged, Aged, 80 and over, Middle Aged, Child, Child, Preschool, Infant, Poison Control Centers, Texas, Female, Male, Young Adult, Psilocybin

raw_json:
{"europe_pmc_id":"19415588","source":"MED","pub_type":null,"publisher":null,"importer":"Europe PMC"}


title: [Mushroom poisoning--the dark side of mycetism].
authors: Flammer R, Schenk-Jäger KM.
publication_date: 2009-04-30
doi: 10.1024/0040-5930.66.5.357
pubmed_id: 19401986
source_url: https://doi.org/10.1024/0040-5930.66.5.357
keywords: Humans, Mushroom Poisoning, Emergencies, Mycotoxins, Adult, Child
substance_tags: psilocybin
topic_tags: General
study_type: Other
source_name: Europe PMC
publication_status: published
date_added: 2026-07-01 06:54:14
last_checked: 2026-07-01 11:22:07
abstract:
Most mushroom intoxications become evident within 12 hours with vomiting and diarrhea. They can be divided into incidents with a short latency (less than four hours) and incidents with a long latency (longer than four hours). As a rule of thumb amatoxin poisonings must be considered in case of symptoms appearing with a long latency (8-12-18 h), especially after consumption of non-controlled wild mushrooms. Shorter latencies do not exclude amatoxin poisoning. Large meals of mushrooms, which are rich in chitin, mixed meals and individual factors, may shorten latency and disguise amatoxin poisoning. Any vomiting and diarrhea after mushroom consumption is suspicious. Unless the mushrooms are not to be identified within 30 minutes by an expert, specific treatment for amatoxin poisoning must be started. Identification shall be achieved by macroscopic or microscopic means; and urine analysis for amatoxins are crucial. By commencing treatment before analysis, mortality rates may be as low as 5%. Current standards in amatoxin poisoning treatment can be obtained at the Swiss Toxicological Information Centre (Phone 145), where contacts to mycologists are available as well. Emergency mycologists are listed on the website www.vapko.ch. Of the 18 different syndromes we present the most common and most important in Switzerland. In an overview all of them are listed. Early gastrointestinal syndrome with its short latency of less than 4 h and indigestion with a very variable latency are the most common. Psychotropic symptoms after consumptions of fly agaric and panther cap are rare, in case of psilocybin-containing mushrooms, symptoms are frequent, but hardly ever lead to medical treatment. In case of renal failure and rhabdomyolysis of unknown origin, completing a patient's history by questioning nutritional habits might reveal causal relationship with ingestion of orellanin-containing mushrooms or tricholoma equestre respectively. Mushrooms in the backyard are attractive for children. We discuss possible approaches.

raw_json:
{"europe_pmc_id":"19401986","source":"MED","pub_type":null,"publisher":null,"importer":"Europe PMC"}


authors: Nef HM, Möllmann H, Hilpert P, Krause N, Troidl C, Weber M, Rolf A, Dill T, Hamm C, Elsässer A.
publication_date: 2008-04-01
doi: 10.1016/j.ijcard.2007.12.064
pubmed_id: 18378018
source_url: https://doi.org/10.1016/j.ijcard.2007.12.064
substance_tags: psilocybin
study_type: Other
source_name: Europe PMC
publication_status: published
date_added: 2026-07-01 06:54:14
last_checked: 2026-07-01 11:22:07
title:
Apical regional wall motion abnormalities reminiscent to Tako-Tsubo cardiomyopathy following consumption of psychoactive fungi.

abstract:
Consumption of natural hallucinogenic substances continues to be a problem. In this case we report from a young male patient presenting with an acute coronary syndrome with significant ST-elevation after the abuse of psychoactive fungi, commonly referred to as "magic mushrooms". Coronary angiography excludes relevant coronary artery disease. In ventriculography contractile dysfunction with hypokinesia in the apical segments could be documented reminiscent to wall motion abnormalities in Tako-Tsubo cardiomyopathy (TTC). Cardiovascular magnetic resonance imaging showed no pathological signal activity in the late-enhancement sequences ruling out myocardial infarction or inflammatory processes. Ventricular function normalized within several days. The active metabolite of psychoactive fungi psilocybin is known to interact with several different dopaminergic, adrenergic and serotonergic receptors. Thus, the pathomechanisms leading to contractile dysfunction after consumption of psychoactive fungi are reminiscent to those documented in TTC.

keywords:
Humans, Hallucinogens, Magnetic Resonance Imaging, Coronary Angiography, Adolescent, Male, Acute Coronary Syndrome, Takotsubo Cardiomyopathy, Psilocybin

topic_tags:
Brain Imaging,Mechanism of Action,Receptor Pharmacology,Aging,Randomized Controlled Trial,Adolescents,Inflammation

raw_json:
{"europe_pmc_id":"18378018","source":"MED","pub_type":null,"publisher":null,"importer":"Europe PMC"}


authors: Björnstad K, Beck O, Helander A.
publication_date: 2009-03-10
doi: 10.1016/j.jchromb.2009.03.004
pubmed_id: 19332394
source_url: https://doi.org/10.1016/j.jchromb.2009.03.004
substance_tags: psilocin
topic_tags: General
study_type: Clinical Trial
source_name: Europe PMC
publication_status: published
date_added: 2026-07-01 06:54:14
last_checked: 2026-07-01 11:22:07
title:
A multi-component LC-MS/MS method for detection of ten plant-derived psychoactive substances in urine.

abstract:
A sensitive and specific LC-MS/MS method for simultaneous detection of 10 plant-derived psychoactive substances (atropine, N,N-dimethyltryptamine, ephedrine, harmaline, harmine, ibogaine, lysergic acid amide, psilocin, scopolamine and yohimbine) in urine was developed. Direct injection of urine diluted with 3 deuterated internal standards allowed for a readily accessible method suitable for application in clinical intoxication cases. Separation was achieved using reversed phase chromatography and gradient elution with a total analysis time of 14 min. Electrospray ionization was used and ions were monitored in the positive selected reaction monitoring mode. The calibration curves were linear (r(2)>0.999) and the total imprecision at high (1000 microg/L) and low (50 microg/L) substance concentrations were 4.9-13.8% and 8.3-26%, respectively. Infusing the analytes post column and injecting matrix samples showed limited influence by ion suppression. The multi-component method proved to be useful for investigation of authentic cases of intoxication with plant-derived psychoactive drugs and was indicated to cover the clinically relevant concentration ranges.

keywords:
Humans, Plants, Psychotropic Drugs, Calibration, Chromatography, High Pressure Liquid, Spectrometry, Mass, Electrospray Ionization, Reproducibility of Results, Hydrolysis, Mass Spectrometry

raw_json:
{"europe_pmc_id":"19332394","source":"MED","pub_type":null,"publisher":null,"importer":"Europe PMC"}


title: GMP-compliant radiosynthesis of [18F]altanserin and human plasma metabolite studies.
publication_date: 2008-12-23
doi: 10.1016/j.apradiso.2008.12.007
pubmed_id: 19162492
source_url: https://doi.org/10.1016/j.apradiso.2008.12.007
substance_tags: psilocybin
topic_tags: Pharmacology,Receptor Pharmacology
study_type: Clinical Trial
source_name: Europe PMC
publication_status: published
date_added: 2026-07-01 06:54:14
last_checked: 2026-07-01 11:22:07
authors:
Hasler F, Kuznetsova OF, Krasikova RN, Cservenyak T, Quednow BB, Vollenweider FX, Ametamey SM, Westera G.

abstract:
[(18)F]altanserin is the preferred radiotracer for in-vivo labeling of serotonin 2A receptors by positron emission tomography (PET). We report a modified synthesis procedure suited for reliable production of multi-GBq amounts of [(18)F]altanserin useful for application in humans. We introduced thermal heating for drying of [(18)F]fluoride as well as for the reaction instead of microwave heating. We furthermore describe solid phase extraction and HPLC procedures for quantitative determination of [(18)F]altanserin and metabolites in plasma. The time course of arterial plasma activity with and without metabolite correction was determined. 90 min after bolus injection, 38.4% of total plasma activity derived from unchanged [(18)F]altanserin. Statistical comparison of kinetic profiles of [(18)F]altanserin metabolism in plasma samples collected in the course of two ongoing studies employing placebo, the serotonin releaser dexfenfluramine and the hallucinogen psilocybin, revealed the same tracer metabolism. We conclude that metabolite analysis for correction of individual plasma input functions used in tracer modeling is not necessary for [(18)F]altanserin studies involving psilocybin or dexfenfluramine treatment.

keywords:
Humans, Fluorine Radioisotopes, Ketanserin, Positron-Emission Tomography, Chromatography, High Pressure Liquid, Quality Control

raw_json:
{"europe_pmc_id":"19162492","source":"MED","pub_type":null,"publisher":null,"importer":"Europe PMC"}


title: [Acute encephalopathy caused by cyanogenic fungi in 2004, and magic mushroom regulation in Japan].
authors: Gonmori K, Yokoyama K
journal: Chudoku kenkyu : Chudoku Kenkyukai jun kikanshi = The Japanese journal of toxicology
publication_date: 2009-02-28
pubmed_id: 19344063
source_url: https://pubmed.ncbi.nlm.nih.gov/19344063/
substance_tags: psilocybin
topic_tags: Headache / Migraine,Consciousness
study_type: Other
source_name: PubMed
publication_status: published
date_added: 2026-07-01 06:54:14
last_checked: 2026-07-01 11:20:41
raw_json: {"pubmed_id":"19344063"}
abstract:
Two topics, related to mushroom poisoning of recent interest in Japan, have been presented. In autumn 2004, 59 cases of acute encephalopathy were reported across 9 prefectures in Japan (24 from Akita Prefecture with 8 deaths; age 48-93, average 70; female 14, male 10). Of 24 cases, 20 had kidney dysfunction. Four poisoned subjects showed no kidney trouble. Of the 24 poisoning cases, 23 people ate Pleurocybella porrigens, and one ate Grifola frondosa. The latter subject (female, late 40's) was receiving dialysis for more than 35 years. In August, she felt dizziness, headache and tinnitus. She visited hospital and asked to stay there. In the hospital she ate 5g of stewed G. frondosa and 10g of the same fungus boiled with chicken and taro on different days. Fourteen to 18 days after the eatings, she developed cramps and lost consciousness, and fell into a coma. Her cramp and coma continued for about 10 days almost until her death. Her symptoms caused by G. frondosa were similar to those observed for the above 23 cases of P. porrigens ingestion. Therefore, we concluded that encephalopathy experienced in Akita Prefecture caused by was the cyanogenic fungi such as P. porrigens, G. frondosa, Pleurotus eringii etc. Although the amounts of mushrooms eaten by poisoned subjects were not so clear, we estimated that the amounts of hydrogen cyanide (HCN) taken into human bodies exceeded the detoxication limit of HCN, resulting in HCN poisoning. However, it has not been proved that the encephalopathy is directly or indirectly caused by the HCN poisoning. Many typhoons came across Japan and landed 10 times in 2004, and mushroom size was larger than usual one, and HCN contents in fruit-bodies seemed to be increased especially in the late-stage of their growth. Thirteen species of magic mushrooms were prohibited by the law from 2002 in Japan. They include Copelandia (Panaeolus) cyanescens, Panaeolus papilionaceus, Panaeolus sphinctrinus, Panaeolus subbalteatus, Psilocybe argentipes, Psilocybe cubensis, Psilocybe fasciata, Psilocybe lonchophorus, Psilocybe subaeruginascens, Psilocybe subcaerulipes, Psilocybe subcubensis, Psilocybe tampanensis, and Psilocybe venenata.


authors: Adams JD.
publication_date: 2008-12-31
doi: 10.2174/092986709789057626
pubmed_id: 19799545
source_url: https://doi.org/10.2174/092986709789057626
substance_tags: psilocybin
study_type: Review Article
source_name: Europe PMC
publication_status: published
date_added: 2026-07-01 06:54:14
last_checked: 2026-07-01 11:22:07
title:
Chemical interactions with pyramidal neurons in layer 5 of the cerebral cortex: control of pain and anxiety.

abstract:
Pyramidal neurons in layer 5 of the cerebral cortex are involved in learning and memory and have complex connections with other neurons through a very large array of dendrites. These dendrites can switch between long term depression and long term potentiation depending on global summation of various inputs. The plasticity of the input into pyramidal neurons makes the neuronal output variable. Many interneurons in the cerebral cortex and distant neurons in other brain regions are involved in providing input to pyramidal neurons. All of these neurons and interneurons have neurotransmitters that act through receptors to provide input to pyramidal neurons. Serotonin is one of the important neurotransmitters involved with pyramidal neurons and has been implicated in psychosis, psychedelic states and what are called sacred dreams. This review will discuss the various chemicals and receptors that are important with pyramidal neurons including opioids, nicotine, scopolamine, psilocybin, LSD, mescaline, ergot alkaloids, salvinorin A, ergine and other compounds that interact with opioid, nicotinic, muscarinic and serotonergic receptors. The natural compounds provide clues to structure activity relationships with the receptors. It has been postulated that each receptor in the body has a natural agonist and antagonist, in addition to the normal neurotransmitters. It is common for natural antagonists and agonists to be peptides. Various possible peptide structures will be proposed for natural antagonists and agonists at each receptor. Natural antagonists and agonists may provide new ways to explore the functions of pyramidal neurons in normal health and pain management.

keywords:
Cerebral Cortex, Neurons, Pain, Peptides, Receptors, Serotonin, 5-HT2, Receptors, Nicotinic, Neurotransmitter Agents, Anxiety

topic_tags:
Depression,Anxiety,Addiction,Chronic Pain,Neuroplasticity,Receptor Pharmacology,Review Article,Drug Interactions

raw_json:
{"europe_pmc_id":"19799545","source":"MED","pub_type":null,"publisher":null,"importer":"Europe PMC"}


title: Agonist-trafficking and hallucinogens.
authors: González-Maeso J, Sealfon SC.
publication_date: 2008-12-31
doi: 10.2174/092986709787581851
pubmed_id: 19275609
source_url: https://doi.org/10.2174/092986709787581851
substance_tags: psilocybin
topic_tags: Mechanism of Action,Receptor Pharmacology,Review Article,In Vitro Study
study_type: Review Article
source_name: Europe PMC
publication_status: published
date_added: 2026-07-01 06:54:14
last_checked: 2026-07-01 11:22:07
abstract:
Seven transmembrane domain receptors, also termed G protein-coupled receptors (GPCRs), represent the most common molecular target for therapeutic drugs. The generally accepted pharmacological model for GPCR activation is the ternary complex model, in which GPCRs exist in a dynamic equilibrium between the active and inactive conformational states. However, the demonstration that different agonists sometimes elicit a different relative activation of two signaling pathways downstream of the same receptor has led to a revision of the ternary complex model. According to this agonist- trafficking model, agonists stabilize distinct activated receptor conformations that preferentially activate specific signaling pathways. Hallucinogenic drugs and non-hallucinogenic drugs represent an attractive experimental system with which to study agonist-trafficking of receptor signaling. Thus many of the behavioral responses induced by hallucinogenic drugs, such as lysergic acid diethylamide (LSD), psilocybin or mescaline, depend on activation of serotonin 5-HT(2A) receptors (5-HT2ARs). In contrast, this neuropsychological state in humans is not induced by closely related chemicals, such as lisuride or ergotamine, despite their similar in vitro activity at the 5-HT2AR. In this review, we summarize the current knowledge, as well as unresolved questions, regarding agonist-trafficking and the mechanism of action of hallucinogenic drugs.

keywords:
Neurons, Animals, Humans, Receptors, Cell Surface, Hallucinogens, Schizophrenia, Signal Transduction, Biological Transport

raw_json:
{"europe_pmc_id":"19275609","source":"MED","pub_type":null,"publisher":null,"importer":"Europe PMC"}


title: Unrecognized magic mushroom abuse in a 28-year-old man.
authors: McClintock RL, Watts DJ, Melanson S
journal: The American journal of emergency medicine
publication_date: 2008-09-30
doi: 10.1016/j.ajem.2008.01.058
pubmed_id: 18926381
source_url: https://pubmed.ncbi.nlm.nih.gov/18926381/
substance_tags: psilocybin
topic_tags: Brain Imaging,Aging,Toxicity
study_type: Other
source_name: PubMed
publication_status: published
date_added: 2026-07-01 06:54:14
last_checked: 2026-07-01 11:20:41
raw_json: {"pubmed_id":"18926381"}
abstract:
A28-year-old man with a history of drug and alcohol abuse presented multiple times to the hospital over 2 months with an elusive constellation of symptoms, resolving spontaneously in each instance. This patient required a high level of care for management and stabilization, including 3 emergency department visits, 2 medical floor admissions, and 1 intensive care unit admission. In both the emergency department and inpatient setting, all laboratory and imaging study results, including gas chromatography/mass spectrophotometry of the urine, were negative/normal. A definitive diagnosis eluded multiple emergency medicine, critical care, and consulting physicians. His symptoms included altered mental status, vomiting, diaphoresis, and mydriasis. The patient later admitted using mushrooms to a nurse. In the absence of confirmatory testing, but supported by exclusionary and anecdotal data, we believe that our patient's symptoms are consistent with Psilocybe mushroom toxicity. We feel that had this been considered initially, the correct diagnosis would have led to a better utilization of resources, and we want to remind emergency physicians of the possibility of mushroom abuse in any similar clinical setting.


title: Serotonin research: contributions to understanding psychoses.
authors: Geyer MA, Vollenweider FX.
publication_date: 2008-08-31
doi: 10.1016/j.tips.2008.06.006
pubmed_id: 19086254
source_url: https://doi.org/10.1016/j.tips.2008.06.006
substance_tags: psilocybin
topic_tags: Brain Imaging,Receptor Pharmacology,Consciousness,Aging,Review Article
study_type: Review Article
source_name: Europe PMC
publication_status: published
date_added: 2026-07-01 06:54:14
last_checked: 2026-07-01 11:22:07
abstract:
The history of serotonin research is closely related to the study of hallucinogenic drugs that function as agonists at serotonin-2A receptors. The fundamental idea that psychotic states seen in psychiatric disorders such as schizophrenia might be attributable, in part, to abnormalities in serotonergic systems began with the almost simultaneous discovery of lysergic acid diethylamide (LSD), psilocybin and serotonin. Sixty years of study have confirmed early speculations regarding the important relationship between serotonin and both drug-induced and disorder-based psychotic states. Now, modern biochemical, pharmacological, behavioral, neuroimaging, genetic and molecular biological sciences are converging to understand how serotonergic systems interact with other monoaminergic and glutamatergic systems to modulate states of consciousness and contribute to psychotic disorders such as the group of schizophrenias. This review summarizes experimental assessments of the serotonergic hallucinogen model psychosis in relation to the serotonin hypothesis of schizophrenia.

keywords:
Animals, Humans, Psychoses, Substance-Induced, Serotonin, Hallucinogens, Psychotic Disorders, Dose-Response Relationship, Drug, Serotonin Receptor Agonists

raw_json:
{"europe_pmc_id":"19086254","source":"MED","pub_type":null,"publisher":null,"importer":"Europe PMC"}


authors: Griffiths R, Richards W, Johnson M, McCann U, Jesse R.
publication_date: 2008-06-30
doi: 10.1177/0269881108094300
pubmed_id: 18593735
source_url: https://doi.org/10.1177/0269881108094300
substance_tags: psilocybin
topic_tags: Wellbeing,Personality Change,Spirituality,Mystical Experience,Observational Study
study_type: Observational Study
source_name: Europe PMC
publication_status: published
date_added: 2026-07-01 06:54:14
last_checked: 2026-07-01 11:22:06
title:
Mystical-type experiences occasioned by psilocybin mediate the attribution of personal meaning and spiritual significance 14 months later.

abstract:
Psilocybin has been used for centuries for religious purposes; however, little is known scientifically about its long-term effects. We previously reported the effects of a double-blind study evaluating the psychological effects of a high psilocybin dose. This report presents the 14-month follow-up and examines the relationship of the follow-up results to data obtained at screening and on drug session days. Participants were 36 hallucinogen-naïve adults reporting regular participation in religious/ spiritual activities. Oral psilocybin (30 mg/70 kg) was administered on one of two or three sessions, with methylphenidate (40 mg/70 kg) administered on the other session(s). During sessions, volunteers were encouraged to close their eyes and direct their attention inward. At the 14-month follow-up, 58% and 67%, respectively, of volunteers rated the psilocybin-occasioned experience as being among the five most personally meaningful and among the five most spiritually significant experiences of their lives; 64% indicated that the experience increased well-being or life satisfaction; 58% met criteria for having had a 'complete' mystical experience. Correlation and regression analyses indicated a central role of the mystical experience assessed on the session day in the high ratings of personal meaning and spiritual significance at follow-up. Of the measures of personality, affect, quality of life and spirituality assessed across the study, only a scale measuring mystical experience showed a difference from screening. When administered under supportive conditions, psilocybin occasioned experiences similar to spontaneously occurring mystical experiences that, at 14-month follow-up, were considered by volunteers to be among the most personally meaningful and spiritually significant of their lives.

keywords:
Humans, Hallucinogens, Administration, Oral, Follow-Up Studies, Affect, Personality, Spirituality, Knowledge, Time Factors, Quality of Life, Religion, Mysticism, Adult, Middle Aged, Female, Male, Surveys and Questionnaires, Psilocybin

raw_json:
{"europe_pmc_id":"18593735","source":"MED","pub_type":null,"publisher":null,"importer":"Europe PMC"}


title: The structure of human serotonin 2c G-protein-coupled receptor bound to agonists and antagonists.
authors: Bray JK, Goddard WA.
publication_date: 2008-03-26
doi: 10.1016/j.jmgm.2008.02.006
pubmed_id: 18499489
source_url: https://doi.org/10.1016/j.jmgm.2008.02.006
substance_tags: psilocybin
topic_tags: Receptor Pharmacology
study_type: Other
source_name: Europe PMC
publication_status: published
date_added: 2026-07-01 06:54:14
last_checked: 2026-07-01 11:22:07
abstract:
We used the MembStruk computational procedure to predict the three-dimensional (3D) structure for the serotonin 5-HT(2C) G-protein-coupled receptor (GPCR). Using this structure, we used the MSCDock computational procedure to predict the 3D structures for bound ligand-protein complexes for agonists such as serotonin and antagonists such as ritanserin, metergoline, and methiothepin. In addition, we predicted the SAR data for a series of psilocybin analogs, both agonists and antagonists. We performed molecular dynamics (MD) on serotonin bound to 5-HT(2C) and we find the protein and binding site to be stable after 5ns. We find good agreement with the currently known experimental data and we predict a number of new mutations which could be used to validate further our predicted structures. This agreement between theory and experiment suggests that our 3D structure is sufficiently accurate for use in drug design. We also compare a preliminary prediction for 5-HT(2B) with our prediction for 5-HT(2C) and find a difference in TM5 that contributes to different serotonin binding modes in 5-HT(2B) and 5-HT(2C).

keywords:
Humans, Serotonin, Metergoline, Ritanserin, Methiothepin, Receptor, Serotonin, 5-HT2B, Receptor, Serotonin, 5-HT2C, Mutagenesis, Binding Sites, Amino Acid Sequence, Protein Structure, Secondary, Structure-Activity Relationship, Kinetics, Thermodynamics, Molecular Sequence Data, Serotonin 5-HT2 Receptor Agonists, Serotonin 5-HT2 Receptor Antagonists, Psilocybin

raw_json:
{"europe_pmc_id":"18499489","source":"MED","pub_type":null,"publisher":null,"importer":"Europe PMC"}


title: Mismatch negativity generation in the human 5HT2A agonist and NMDA antagonist model of psychosis.
publication_date: 2008-05-17
doi: 10.1007/s00213-008-1129-4
pubmed_id: 18488201
source_url: https://doi.org/10.1007/s00213-008-1129-4
substance_tags: psilocybin
topic_tags: Receptor Pharmacology
study_type: Clinical Trial
source_name: Europe PMC
publication_status: published
date_added: 2026-07-01 06:54:14
last_checked: 2026-07-01 11:22:07
authors:
Heekeren K, Daumann J, Daumann J, Neukirch A, Stock C, Kawohl W, Norra C, Waberski TD, Gouzoulis-Mayfrank E.

abstract:
RationaleMany studies have reported deficits of mismatch negativity (MMN) in schizophrenic patients. Pharmacological challenges with hallucinogens in healthy humans are used as models for psychotic states. Previous studies reported a significant reduction of MMN after ketamine (N-methyl-D-aspartate acid [NMDA] antagonist model) but not after psilocybin (5HT2A agonist model).ObjectivesThe aim of the present study was to directly compare the two models of psychosis using an intraindividual crossover design.Materials and methodsFifteen healthy subjects participated in a randomized, double-blind, crossover study with a low and a high dose of the 5HT2A agonist dimethyltryptamine (DMT) and the NMDA antagonist S-ketamine. During electroencephalographic recording, the subjects were performing the AX-version of a continuous performance test (AX-CPT). A source analysis of MMN was performed on the basis of a four-source model of MMN generation.ResultsNine subjects completed both experimental days with the two doses of both drugs. Overall, we found blunted MMN and performance deficits in the AX-CPT after both drugs. However, the reduction in MMN activity was overall more pronounced after S-ketamine intake, and only S-ketamine had a significant impact on the frontal source of MMN.ConclusionsThe NDMA antagonist model and the 5HT2A agonist model of psychosis display distinct neurocognitive profiles. These findings are in line with the view of the two classes of hallucinogens modeling different aspects of psychosis.

keywords:
Cerebral Cortex, Humans, Psychoses, Substance-Induced, N,N-Dimethyltryptamine, Ketamine, Receptors, N-Methyl-D-Aspartate, Excitatory Amino Acid Antagonists, Electroencephalography, Brain Mapping, Cross-Over Studies, Double-Blind Method, Orientation, Auditory Perception, Pattern Recognition, Visual, Psychomotor Performance, Attention, Contingent Negative Variation, Dose-Response Relationship, Drug, Signal Processing, Computer-Assisted, Adult, Middle Aged, Female, Male, Serotonin Receptor Agonists, Serotonin 5-HT2 Receptor Agonists, Reflex, Startle, Inhibition, Psychological

raw_json:
{"europe_pmc_id":"18488201","source":"MED","pub_type":null,"publisher":null,"importer":"Europe PMC"}


title: [Hallucinogen-induced psychological disorders].
authors: Hermle L, Kovar KA, Hewer W, Ruchsow M.
publication_date: 2008-05-31
doi: 10.1055/s-2008-1038191
pubmed_id: 18512184
source_url: https://doi.org/10.1055/s-2008-1038191
substance_tags: psilocybin
topic_tags: Review Article,Adolescents
study_type: Review Article
source_name: Europe PMC
publication_status: published
date_added: 2026-07-01 06:54:14
last_checked: 2026-07-01 11:22:07
abstract:
ObjectiveThe purpose of this article is to provide an overview of the current research on hallucinogen induced psychiatric disorders. In addition to LSD and psilocybin hallucinogens of biologic origin are increasingly used by adolescents and young adults.MethodsRelevant literature and related articles were identified by means of a computerized MEDLINE search including the years 1997 - 2007. As keywords "hallucinogen induced psychosis", "hallucinogen induced flashback", "hallucinogen persisting perception disorder (HPPD)" were used. Finally, 64 journal articles and books out of 103 were included in the review.ResultsAcute psychotic syndromes in adolescents are rarely due to intoxications with hallucinogenic drugs. However, clinical relevance of flashback phenomena as post-hallucinogenic psychiatric disorder has to be disputed. Because of the high popularity of biogenic hallucinogens and LSD knowledge of intoxications and resulting psychiatric disorders as well as medical complications and therapeutical approaches are clinically important. Especially intoxications with drugs of herbal origin like tropanalcaloids play an important role in emergency situations.

keywords:
Humans, Psychoses, Substance-Induced, Substance-Related Disorders, Recurrence, N,N-Dimethyltryptamine, Lysergic Acid Diethylamide, Hallucinogens, Adolescent, Adult, Psilocybin

raw_json:
{"europe_pmc_id":"18512184","source":"MED","pub_type":null,"publisher":null,"importer":"Europe PMC"}


title: Effects of varied doses of psilocybin on time interval reproduction in human subjects.
authors: Wackermann J, Wittmann M, Hasler F, Vollenweider FX.
publication_date: 2008-02-08
doi: 10.1016/j.neulet.2008.02.006
pubmed_id: 18325673
source_url: https://doi.org/10.1016/j.neulet.2008.02.006
substance_tags: psilocybin
topic_tags: Consciousness
study_type: Qualitative Study
source_name: Europe PMC
publication_status: published
date_added: 2026-07-01 06:54:14
last_checked: 2026-07-01 11:22:06
abstract:
Action of a hallucinogenic substance, psilocybin, on internal time representation was investigated in two double-blind, placebo-controlled studies: Experiment 1 with 12 subjects and graded doses, and Experiment 2 with 9 subjects and a very low dose. The task consisted in repeated reproductions of time intervals in the range from 1.5 to 5s. The effects were assessed by parameter kappa of the 'dual klepsydra' model of internal time representation, fitted to individual response data and intra-individually normalized with respect to initial values. The estimates kappa were in the same order of magnitude as in earlier studies. In both experiments, kappa was significantly increased by psilocybin at 90 min from the drug intake, indicating a higher loss rate of the internal duration representation. These findings are tentatively linked to qualitative alterations of subjective time in altered states of consciousness.

keywords:
Brain, Humans, Consciousness Disorders, Hallucinogens, Mental Processes, Cognition, Time Perception, Judgment, Dose-Response Relationship, Drug, Time Factors, Adult, Female, Male, Psilocybin

raw_json:
{"europe_pmc_id":"18325673","source":"MED","pub_type":null,"publisher":null,"importer":"Europe PMC"}


title: Identification of a serotonin/glutamate receptor complex implicated in psychosis.
publication_date: 2008-02-23
doi: 10.1038/nature06612
pubmed_id: 18297054
source_url: https://doi.org/10.1038/nature06612
substance_tags: psilocybin
topic_tags: Receptor Pharmacology,Animal Study
study_type: Animal Study
source_name: Europe PMC
publication_status: published
date_added: 2026-07-01 06:54:14
last_checked: 2026-07-01 11:22:07
authors:
González-Maeso J, Ang RL, Yuen T, Chan P, Weisstaub NV, López-Giménez JF, Zhou M, Okawa Y, Callado LF, Callado LF, Milligan G, Gingrich JA, Filizola M, Meana JJ, Sealfon SC.

abstract:
The psychosis associated with schizophrenia is characterized by alterations in sensory processing and perception. Some antipsychotic drugs were identified by their high affinity for serotonin 5-HT2A receptors (2AR). Drugs that interact with metabotropic glutamate receptors (mGluR) also have potential for the treatment of schizophrenia. The effects of hallucinogenic drugs, such as psilocybin and lysergic acid diethylamide, require the 2AR and resemble some of the core symptoms of schizophrenia. Here we show that the mGluR2 interacts through specific transmembrane helix domains with the 2AR, a member of an unrelated G-protein-coupled receptor family, to form functional complexes in brain cortex. The 2AR-mGluR2 complex triggers unique cellular responses when targeted by hallucinogenic drugs, and activation of mGluR2 abolishes hallucinogen-specific signalling and behavioural responses. In post-mortem human brain from untreated schizophrenic subjects, the 2AR is upregulated and the mGluR2 is downregulated, a pattern that could predispose to psychosis. These regulatory changes indicate that the 2AR-mGluR2 complex may be involved in the altered cortical processes of schizophrenia, and this complex is therefore a promising new target for the treatment of psychosis.

keywords:
Brain, Cells, Cultured, Cell Line, Animals, Humans, Mice, Multiprotein Complexes, Receptors, Metabotropic Glutamate, Receptor, Serotonin, 5-HT2A, Hallucinogens, Psychotic Disorders, Schizophrenia, Signal Transduction, Down-Regulation, Up-Regulation, Protein Structure, Tertiary, Protein Binding, Models, Molecular

raw_json:
{"europe_pmc_id":"18297054","source":"MED","pub_type":null,"publisher":null,"importer":"Europe PMC"}


title: Chemical Constituents of Gymnopilus spectabilis and Their Antioxidant Activity.
authors: Lee IK, Cho SM, Seok SJ, Yun BS.
publication_date: 2008-03-30
doi: 10.4489/myco.2008.36.1.055
pubmed_id: 23997609
source_url: https://doi.org/10.4489/myco.2008.36.1.055
substance_tags: psilocybin
topic_tags: General
study_type: Other
source_name: Europe PMC
publication_status: published
date_added: 2026-07-01 06:54:14
last_checked: 2026-07-01 11:22:07
abstract:
Gymnopilus spectabilis, a hallucinogenic mushroom belonging to the family Cortinariaceae, is found growing in dense clusters on stumps and logs of hardwoods and conifers. It contains the hallucinogenic alkaloid psilocybin and its strongly bitter taste makes it undesirable as an edible. In an effort to identify chemical constituents of Korean native wild mushrooms, 4,6-decadiyne-1,3,8-triol (1), ergosta-4,6,8(14), 22-tetraen-3-one (2), bisnoryangonin (3), and hispidin (4) were isolated from the methanolic extract of the fruiting bodies of G. spectabilis. Their structures were assigned on the basis of various spectroscopic studies. Compounds 3 and 4 displayed significant scavenging activity against the ABTS radical cation, DPPH radical, and superoxide radical anion, while 1 and 2 exhibited no antioxidant activity.

raw_json:
{"europe_pmc_id":"23997609","source":"MED","pub_type":null,"publisher":null,"importer":"Europe PMC"}


title: Between prohibitions: patterns and meanings of magic mushroom use in the UK.
authors: Riley SC, Blackman G
journal: Substance use & misuse
publication_date: 2007-12-31
doi: 10.1080/10826080701772363
pubmed_id: 18189205
source_url: https://pubmed.ncbi.nlm.nih.gov/18189205/
substance_tags: psilocybin
topic_tags: Anxiety,Observational Study
study_type: Observational Study
source_name: PubMed
publication_status: published
date_added: 2026-07-01 06:54:14
last_checked: 2026-07-01 11:20:41
raw_json: {"pubmed_id":"18189205"}
abstract:
A survey of magic mushroom use was completed by 174 participants in 2004, a year when the sale of hallucinogenic mushrooms was not illegal in the UK. The data were collected in Edinburgh and Bristol (UK). Participants were a self-selecting convenience sample. Participants tended to be in their 20s, White-British, in education or employed; 64% were male. Participants reported a pattern of infrequent but intense consumption (47% used between 4-12 times/year, average consumption in one setting was 12 g, a high dose). Use was explained in terms of laughing, hallucinations, altering perspective (41-74%), and feelings of being closer to nature (49%). Negative experiences reported included paranoia (35%) and anxiety (32%). Mushroom use was located within a wider recreational drug and alcohol culture. Four focus groups aided the interpretation of the data. Future research is recommended into negative experiences. Implications for policy and harm minimisation literature are discussed.


title: Antagonism of phencyclidine-induced stimulus control in the rat by other psychoactive drugs.
authors: Winter JC.
publication_date: 2007-08-14
doi: 10.1016/j.pbb.2007.07.007
pubmed_id: 17936884
source_url: https://doi.org/10.1016/j.pbb.2007.07.007
substance_tags: psilocybin
topic_tags: Receptor Pharmacology,Animal Study,Toxicity,Drug Interactions
study_type: Animal Study
source_name: Europe PMC
publication_status: published
date_added: 2026-07-01 06:54:14
last_checked: 2026-07-01 11:22:07
abstract:
It has been observed that agents with agonist activity at 5-HT2A receptors prevent neurotoxicity induced by the non-competitive NMDA antagonist, dizocilpine (MK-801). Subsequent behavioral studies reported complete antagonism by LSD and DOM of the stimulus effects of the related NMDA antagonist, phencyclidine [PCP]. The present study sought to extend those observations to include other psychoactive drugs. Male F-344 rats were trained in a 2-lever, fixed-ratio 10, food-reinforced task with PCP (3.0 mg/kg; IP; 30 min pretreatment) as a discriminative stimulus. Tests of generalization were then conducted using the training dose of PCP in combination with a range of doses of DOM, LSD, d-amphetamine, MDMA, psilocybin, buspirone, and GHB. All of the drugs tested in combination with PCP produced a statistically significant diminution of PCP-appropriate responding but for none was antagonism complete. These data, obtained using a stimulus control model of the hallucinogenic effects of PCP, fail to support the hypothesis that LSD and DOM completely antagonize stimulus control by PCP. Instead, the data suggest complex interactions between PCP-induced stimulus control and a variety of psychoactive drugs including GHB, an agent with no known affinity for serotonergic receptors.

keywords:
Animals, Rats, Inbred F344, Rats, Sodium Oxybate, Phencyclidine, Dopamine Agents, Excitatory Amino Acid Antagonists, Serotonin Agents, Anesthetics, Intravenous, Hallucinogens, Psychotropic Drugs, Conditioning, Operant, Dose-Response Relationship, Drug, Male

raw_json:
{"europe_pmc_id":"17936884","source":"MED","pub_type":null,"publisher":null,"importer":"Europe PMC"}


authors: Fantegrossi WE, Reissig CJ, Katz EB, Yarosh HL, Rice KC, Winter JC.
publication_date: 2007-09-13
doi: 10.1016/j.pbb.2007.09.007
pubmed_id: 17905422
source_url: https://doi.org/10.1016/j.pbb.2007.09.007
substance_tags: psilocybin
topic_tags: Receptor Pharmacology,Animal Study
study_type: Animal Study
source_name: Europe PMC
publication_status: published
date_added: 2026-07-01 06:54:14
last_checked: 2026-07-01 11:22:07
title:
Hallucinogen-like effects of N,N-dipropyltryptamine (DPT): possible mediation by serotonin 5-HT1A and 5-HT2A receptors in rodents.

abstract:
N,N-dipropyltryptamine (DPT) is a synthetic tryptamine hallucinogen which has been used psychotherapeutically in humans, but has been studied preclinically only rarely. In the present studies, DPT was tested in a drug-elicited head-twitch assay in mice, and in rats trained to discriminate lysergic acid diethylamide (LSD), N,N-dimethyl-4-phosphoryloxytryptamine (psilocybin), or 3,4-methylenedioxymethamphetamine (MDMA). A separate group of rats was also trained to recognize DPT itself as a discriminative stimulus, and in all cases, the behavioral effects of DPT were challenged with the selective serotonin (5-HT)2A antagonist M100907, the 5-HT1A selective antagonist WAY-100635, or their combination. In the head-twitch assay, DPT elicited dose-dependent effects, producing a biphasic dose-effect curve. WAY-100635 produced a parallel rightward shift in the dose-effect curve for head twitches, indicative of surmountable antagonism, but the antagonist effects of M100907 were functionally insurmountable. DPT produced partial to full substitution when tested in rats trained to discriminate LSD, psilocybin or MDMA, and served as a discriminative stimulus. In all cases, the antagonist effects of M100907 were more profound than were those of WAY-100635. DPT is thus active in two rodent models relevant to 5-HT2 agonist activity. The effectiveness with which M100907 antagonizes the behavioral actions of this compound strongly suggest that the 5-HT2A receptor is an important site of action for DPT, but the modulatory actions of WAY-100635 also imply a 5-HT1A-mediated component to the actions of this compound.

keywords:
Animals, Rats, Inbred F344, Mice, Rats, Tryptamines, N-Methyl-3,4-methylenedioxyamphetamine, Fluorobenzenes, Lysergic Acid Diethylamide, Piperazines, Piperidines, Pyridines, Receptor, Serotonin, 5-HT1A, Receptor, Serotonin, 5-HT2A, Serotonin Antagonists, Hallucinogens, Data Interpretation, Statistical, Discrimination Learning, Dose-Response Relationship, Drug, Male, Psilocybin

raw_json:
{"europe_pmc_id":"17905422","source":"MED","pub_type":null,"publisher":null,"importer":"Europe PMC"}


title: [Automutilation after consumption of hallucinogenic mushrooms].
authors: Attema-de Jonge ME, Portier CB, Franssen EJ.
publication_date: 2007-11-30
pubmed_id: 18257429
source_url: https://europepmc.org/article/MED/18257429
substance_tags: psilocybin,psilocin
topic_tags: Addiction,Toxicity
study_type: Other
source_name: Europe PMC
publication_status: published
date_added: 2026-07-01 06:54:14
last_checked: 2026-07-01 11:22:06
abstract:
Two young men, 25 and 32 years old, presented with severe automutilation by knife wounds after consumption of hallucinogenic mushrooms. The first patient had also used cocaine, cannabis and alcohol, while the second patient had only used the hallucinogenic mushrooms. Both patients were treated symptomatically and survived despite their severe stab wounds. Psilocybin-containing mushrooms are used as mind-altering drugs. These drugs may sometimes induce 'bad trips', a psychotic reaction accompanied by fear, panic, and dangerous behaviour, especially when used in combination with other drugs and alcohol or by psychiatrically unstable patients. During a bad trip, patients may hurt themselves. Because the duration of the psychotic and sympathicomimetic effects of psilocybin after ingestion of mushrooms is short (up to 6 h), and since psilocin itself causes no permanent organ toxicity, the treatment of psilocybin intoxication is only symptomatic. The diagnosis ofpsilocybin intoxication is hampered by the lack of routinely available, rapid and sensitive, analytical methods for the quantification ofpsilocybin and its active metabolite psilocin.

keywords:
Humans, Agaricales, Mushroom Poisoning, Substance-Related Disorders, Self Mutilation, Hallucinogens, Adult, Male, Psilocybin

raw_json:
{"europe_pmc_id":"18257429","source":"MED","pub_type":null,"publisher":null,"importer":"Europe PMC"}


authors: Carter OL, Hasler F, Pettigrew JD, Wallis GM, Liu GB, Vollenweider FX.
publication_date: 2007-09-13
doi: 10.1007/s00213-007-0930-9
pubmed_id: 17874073
source_url: https://doi.org/10.1007/s00213-007-0930-9
substance_tags: psilocybin
topic_tags: Receptor Pharmacology
study_type: Other
source_name: Europe PMC
publication_status: published
date_added: 2026-07-01 06:54:14
last_checked: 2026-07-01 11:22:06
title:
Psilocybin links binocular rivalry switch rate to attention and subjective arousal levels in humans.

abstract:
RationaleBinocular rivalry occurs when different images are simultaneously presented to each eye. During continual viewing of this stimulus, the observer will experience repeated switches between visual awareness of the two images. Previous studies have suggested that a slow rate of perceptual switching may be associated with clinical and drug-induced psychosis.ObjectivesThe objective of the study was to explore the proposed relationship between binocular rivalry switch rate and subjective changes in psychological state associated with 5-HT2A receptor activation.Materials and methodsThis study used psilocybin, the hallucinogen found naturally in Psilocybe mushrooms that had previously been found to induce psychosis-like symptoms via the 5-HT2A receptor. The effects of psilocybin (215 microg/kg) were considered alone and after pretreatment with the selective 5-HT2A antagonist ketanserin (50 mg) in ten healthy human subjects.ResultsPsilocybin significantly reduced the rate of binocular rivalry switching and increased the proportion of transitional/mixed percept experience. Pretreatment with ketanserin blocked the majority of psilocybin's "positive" psychosis-like hallucinogenic symptoms. However, ketanserin had no influence on either the psilocybin-induced slowing of binocular rivalry or the drug's "negative-type symptoms" associated with reduced arousal and vigilance.ConclusionsTogether, these findings link changes in binocular rivalry switching rate to subjective levels of arousal and attention. In addition, it suggests that psilocybin's effect on binocular rivalry is unlikely to be mediated by the 5-HT2A receptor.

keywords:
Humans, Ketanserin, Hallucinogens, Drug Combinations, Double-Blind Method, Vision Disparity, Arousal, Attention, Vision, Binocular, Adult, Female, Male, Serotonin 5-HT2 Receptor Agonists, Serotonin 5-HT2 Receptor Antagonists, Psilocybin

raw_json:
{"europe_pmc_id":"17874073","source":"MED","pub_type":null,"publisher":null,"importer":"Europe PMC"}


authors: del Mar Ramirez Fernandez M, Laloup M, Wood M, De Boeck G, Lopez-Rivadulla M, Wallemacq P, Samyn N.
publication_date: 2007-09-30
doi: 10.1093/jat/31.8.497
pubmed_id: 17988464
source_url: https://doi.org/10.1093/jat/31.8.497
substance_tags: psilocin
topic_tags: General
study_type: Clinical Trial
source_name: Europe PMC
publication_status: published
date_added: 2026-07-01 06:54:14
last_checked: 2026-07-01 11:22:07
title:
Liquid chromatography-tandem mass spectrometry method for the simultaneous analysis of multiple hallucinogens, chlorpheniramine, ketamine, ritalinic acid, and metabolites, in urine.

abstract:
A validated method for the simultaneous analysis of multiple hallucinogens, chlorpheniramine, ketamine, ritalinic acid, and several metabolites is presented. The procedure comprises a sample clean-up step, using mixed-mode solid-phase extraction followed by liquid chromatography (LC)-tandem mass spectrometry analysis. Chromatographic separation was achieved using a Sunfire C(8) column eluted with a mixture of formate buffer, methanol, and acetonitrile. The applied LC gradient ensured the elution of all the drugs examined within 14 min and produced chromatographic peaks of acceptable symmetry. Selectivity of the method was achieved by a combination of retention time and two precursor-product ion transitions for the non-deuterated analogues. Validation of the method was performed using 500 microL of urine. The limits of quantification (LOQ) for LSD and 2-oxo-3-hydroxy-LSD were 0.05 and 1 ng/mL, respectively, and ranged, for the other hallucinogens, from 0.5 to 10 ng/mL. Linear and quadratic regression was observed from the LOQ of each compound to 12.5 ng/mL for LSD, 50 ng/mL for 2-oxo-3-hydroxy-LSD and 500 ng/mL for the others (r(2) > 0.99). Precision for the QC samples, spiked at a minimum of two concentrations, was calculated [%CV and %bias < 20% for most of the compounds, except for bufotenine and cathinone (%bias < 24%), and ibogaine (%bias < 30%)]. Extraction was found to be both reproducible and efficient with recoveries > 87% for all the analytes. Furthermore, the processed samples were demonstrated to be stable in the autosampler for at least 24 h. Finally, the validated method was applied to the determination of chlorpheniramine, ketamine, LSD, and psilocin in authentic urine samples.

keywords:
Humans, Methylphenidate, Ketamine, Chlorpheniramine, Hallucinogens, Chromatography, High Pressure Liquid, Spectrometry, Mass, Electrospray Ionization, Reproducibility of Results, Substance Abuse Detection, Tandem Mass Spectrometry, Illicit Drugs

raw_json:
{"europe_pmc_id":"17988464","source":"MED","pub_type":null,"publisher":null,"importer":"Europe PMC"}


title: Psilocybin-induced stimulus control in the rat.
authors: Winter JC, Rice KC, Amorosi DJ, Rabin RA.
publication_date: 2007-06-21
doi: 10.1016/j.pbb.2007.06.003
pubmed_id: 17688928
source_url: https://doi.org/10.1016/j.pbb.2007.06.003
substance_tags: psilocybin,psilocin
topic_tags: Receptor Pharmacology,Animal Study
study_type: Animal Study
source_name: Europe PMC
publication_status: published
date_added: 2026-07-01 06:54:14
last_checked: 2026-07-01 11:22:05
abstract:
Although psilocybin has been trained in the rat as a discriminative stimulus, little is known of the pharmacological receptors essential for stimulus control. In the present investigation rats were trained with psilocybin and tests were then conducted employing a series of other hallucinogens and presumed antagonists. An intermediate degree of antagonism of psilocybin was observed following treatment with the 5-HT(2A) receptor antagonist, M100907. In contrast, no significant antagonism was observed following treatment with the 5-HT(1A/7) receptor antagonist, WAY-100635, or the DA D(2) antagonist, remoxipride. Psilocybin generalized fully to DOM, LSD, psilocin, and, in the presence of WAY-100635, DMT while partial generalization was seen to 2C-T-7 and mescaline. LSD and MDMA partially generalized to psilocybin and these effects were completely blocked by M-100907; no generalization of PCP to psilocybin was seen. The present data suggest that psilocybin induces a compound stimulus in which activity at the 5-HT(2A) receptor plays a prominent but incomplete role. In addition, psilocybin differs from closely related hallucinogens such as 5-MeO-DMT in that agonism at 5-HT(1A) receptors appears to play no role in psilocybin-induced stimulus control.

keywords:
Animals, Rats, Inbred F344, Rats, N-Methyl-3,4-methylenedioxyamphetamine, Lysergic Acid Diethylamide, Phencyclidine, Hallucinogens, Data Interpretation, Statistical, Conditioning, Operant, Generalization, Stimulus, Reinforcement Schedule, Dose-Response Relationship, Drug, Male, Psilocybin, Discrimination, Psychological

raw_json:
{"europe_pmc_id":"17688928","source":"MED","pub_type":null,"publisher":null,"importer":"Europe PMC"}


authors: Marona-Lewicka D, Nichols DE.
publication_date: 2007-06-13
doi: 10.1016/j.pbb.2007.06.001
pubmed_id: 17618679
source_url: https://doi.org/10.1016/j.pbb.2007.06.001
substance_tags: psilocin
topic_tags: Pharmacology,Receptor Pharmacology,Drug Interactions
study_type: Clinical Trial
source_name: Europe PMC
publication_status: published
date_added: 2026-07-01 06:54:14
last_checked: 2026-07-01 11:22:07
title:
Further evidence that the delayed temporal dopaminergic effects of LSD are mediated by a mechanism different than the first temporal phase of action.

abstract:
Activation of 5-HT(2A) receptors is thought to mediate the hallucinogenic effects of LSD. Nevertheless, in a previous report we provided evidence that a delayed temporal phase of the behavioral pharmacology of LSD is mediated by D(2)-like dopamine receptor stimulation. In this study rats were trained to discriminate LSD with either a 30 min preinjection time (LSD-30, N=12) or a 90 min preinjection time (LSD-90, N=13) from saline, using a two-lever, food-reinforced operant conditioning task. We then tested a large number of agonists and antagonists belonging to distinct pharmacological classes in these animals. As anticipated, classical hallucinogens such as psilocin and mescaline substituted only in LSD-30 rats, and not in LSD-90 rats. The dopamine receptor agonists ABT-724, aripiprazole, dihydrexidine, WAY100635, and SKF38393, fully or partially mimicked LSD-90, but not LSD-30. The results reported here support and extend our previous conclusion that the delayed temporal effects of LSD are mediated by activation of a dopaminergic system.

keywords:
Animals, Rats, Rats, Sprague-Dawley, Dopamine, Lysergic Acid Diethylamide, Receptor, Serotonin, 5-HT2A, Neurotransmitter Agents, Dopamine Agonists, Hallucinogens, Data Interpretation, Statistical, Conditioning, Operant, Discrimination Learning, Dose-Response Relationship, Drug, Drug Interactions, Food, Male, Serotonin Receptor Agonists

raw_json:
{"europe_pmc_id":"17618679","source":"MED","pub_type":null,"publisher":null,"importer":"Europe PMC"}


authors: Vollenweider FX, Csomor PA, Knappe B, Geyer MA, Quednow BB.
publication_date: 2007-02-13
doi: 10.1038/sj.npp.1301324
pubmed_id: 17299516
source_url: https://doi.org/10.1038/sj.npp.1301324
substance_tags: psilocybin
topic_tags: Receptor Pharmacology,Consciousness,Animal Study
study_type: Clinical Trial
source_name: Europe PMC
publication_status: published
date_added: 2026-07-01 06:54:14
last_checked: 2026-07-01 11:22:06
title:
The effects of the preferential 5-HT2A agonist psilocybin on prepulse inhibition of startle in healthy human volunteers depend on interstimulus interval.

abstract:
Schizophrenia patients exhibit impairments in prepulse inhibition (PPI) of the startle response. Hallucinogenic 5-HT(2A) receptor agonists are used for animal models of schizophrenia because they mimic some symptoms of schizophrenia in humans and induce PPI deficits in animals. Nevertheless, one report indicates that the 5-HT(2A) receptor agonist psilocybin increases PPI in healthy humans. Hence, we investigated these inconsistent results by assessing the dose-dependent effects of psilocybin on PPI in healthy humans. Sixteen subjects each received placebo or 115, 215, and 315 microg/kg of psilocybin at 4-week intervals in a randomized and counterbalanced order. PPI at 30-, 60-, 120-, 240-, and 2000-ms interstimulus intervals (ISIs) was measured 90 and 165 min after drug intake, coinciding with the peak and post-peak effects of psilocybin. The effects of psilocybin on psychopathological core dimensions and sustained attention were assessed by the Altered States of Consciousness Rating Scale (5D-ASC) and the Frankfurt Attention Inventory (FAIR). Psilocybin dose-dependently reduced PPI at short (30 ms), had no effect at medium (60 ms), and increased PPI at long (120-2000 ms) ISIs, without affecting startle reactivity or habituation. Psilocybin dose-dependently impaired sustained attention and increased all 5D-ASC scores with exception of Auditory Alterations. Moreover, psilocybin-induced impairments in sustained attention performance were positively correlated with reduced PPI at the 30 ms ISI and not with the concomitant increases in PPI observed at long ISIs. These results confirm the psilocybin-induced increase in PPI at long ISIs and reveal that psilocybin also produces a decrease in PPI at short ISIs that is correlated with impaired attention and consistent with deficient PPI in schizophrenia.

keywords:
Humans, Acoustic Stimulation, Analysis of Variance, Double-Blind Method, Attention, Psychological Tests, Dose-Response Relationship, Drug, Time Factors, Adult, Female, Male, Serotonin 5-HT2 Receptor Agonists, Reflex, Startle, Psilocybin, Inhibition, Psychological

raw_json:
{"europe_pmc_id":"17299516","source":"MED","pub_type":null,"publisher":null,"importer":"Europe PMC"}


title: [Hallucinogenic fungi (psilocybe). Part II. Identification of Psilocybe semilanceata by PCR].
authors: Adamczyk A, Sadakierska-Chudy A, Janoszka J, Rymkiewicz A, Dobosz T.
publication_date: 2007-06-30
pubmed_id: 17907620
source_url: https://europepmc.org/article/MED/17907620
substance_tags: psilocybin,psilocin
topic_tags: Adolescents,Toxicity
study_type: Other
source_name: Europe PMC
publication_status: published
date_added: 2026-07-01 06:54:14
last_checked: 2026-07-01 11:22:06
abstract:
Psilocybe semilanceata belongs to the genus of Psilocybe; it is a hallucinogenic fungus, frequently found in regions with high rainfall, in the grass and moss. There are estimated to be as many as eight Psilocybe hallucinogenic species containing psychoactive alkaloids, such as psilocybin and psilocin, which may cause visual, auditory and other hallucinations, as well as profound changes in the perception of time and space. Since identification of P semilanceata in a form different than a fresh mushroom is almost impossible, the authors made an attempt at developing a method of fungi identification based on the PCR technique, which could be helpful in a fight against dangerous consumption of these hallucinogens by the youth. Detection of the specific DNA sequence for P semilanceata brought good results; the test may be commonly employed in forensic practice in the future.

keywords:
Humans, Agaricales, Substance-Related Disorders, Hallucinogens, Substance Abuse Detection, Toxicology, Polymorphism, Restriction Fragment Length, Drug and Narcotic Control, Psilocybin

raw_json:
{"europe_pmc_id":"17907620","source":"MED","pub_type":null,"publisher":null,"importer":"Europe PMC"}


authors: Heekeren K, Neukirch A, Daumann J, Stoll M, Obradovic M, Kovar KA, Geyer MA, Gouzoulis-Mayfrank E.
publication_date: 2007-04-30
doi: 10.1177/0269881107077734
pubmed_id: 17591658
source_url: https://doi.org/10.1177/0269881107077734
substance_tags: psilocybin
topic_tags: Healthy Volunteers
study_type: Other
source_name: Europe PMC
publication_status: published
date_added: 2026-07-01 06:54:14
last_checked: 2026-07-01 11:22:07
title:
Prepulse inhibition of the startle reflex and its attentional modulation in the human S-ketamine and N,N-dimethyltryptamine (DMT) models of psychosis.

abstract:
Patients with schizophrenia exhibit diminished prepulse inhibition (PPI) of the acoustic startle reflex and deficits in the attentional modulation of PPI. Pharmacological challenges with hallucinogens are used as models for psychosis in both humans and animals. Remarkably, in contrast to the findings in schizophrenic patients and in animal hallucinogen models of psychosis, previous studies with healthy volunteers demonstrated increased levels of PPI after administration of low to moderate doses of either the antiglutamatergic hallucinogen ketamine or the serotonergic hallucinogen psilocybin. The aim of the present study was to investigate the influence of moderate and high doses of the serotonergic hallucinogen N,N-dimethyltryptamine (DMT) and the N-methyl-D-aspartate antagonist S-ketamine on PPI and its attentional modulation in humans. Fifteen healthy volunteers were included in a double-blind cross-over study with two doses of DMT and S-ketamine. Effects on PPI and its attentional modulation were investigated. Nine subjects completed both experimental days with the two doses of both drugs. S-ketamine increased PPI in both dosages, whereas DMT had no significant effects on PPI. S-ketamine decreased and DMT tended to decrease startle magnitude. There were no significant effects of either drug on the attentional modulation of PPI. In human experimental hallucinogen psychoses, and even with high, clearly psychotogenic doses of DMT or S-ketamine, healthy subjects failed to exhibit the predicted attenuation of PPI. In contrast, PPI was augmented and the startle magnitude was decreased after S-ketamine. These data point to important differences between human hallucinogen models and both animal hallucinogen models of psychosis and naturally occurring schizophrenia.

keywords:
Humans, Psychoses, Substance-Induced, Substance-Related Disorders, N,N-Dimethyltryptamine, Ketamine, Excitatory Amino Acid Antagonists, Hallucinogens, Double-Blind Method, Psychomotor Performance, Attention, Adult, Middle Aged, Female, Male, Reflex, Startle

raw_json:
{"europe_pmc_id":"17591658","source":"MED","pub_type":null,"publisher":null,"importer":"Europe PMC"}


publication_date: 2007-01-31
doi: 10.1016/j.neuron.2007.01.008
pubmed_id: 17270739
source_url: https://doi.org/10.1016/j.neuron.2007.01.008
substance_tags: psilocybin
topic_tags: Mechanism of Action,Receptor Pharmacology,Animal Study
study_type: Animal Study
source_name: Europe PMC
publication_status: published
date_added: 2026-07-01 06:54:14
last_checked: 2026-07-01 11:22:07
title:
Hallucinogens recruit specific cortical 5-HT(2A) receptor-mediated signaling pathways to affect behavior.

authors:
González-Maeso J, Weisstaub NV, Zhou M, Chan P, Ivic L, Ang R, Lira A, Bradley-Moore M, Ge Y, Zhou Q, Sealfon SC, Gingrich JA.

abstract:
Hallucinogens, including mescaline, psilocybin, and lysergic acid diethylamide (LSD), profoundly affect perception, cognition, and mood. All known drugs of this class are 5-HT(2A) receptor (2AR) agonists, yet closely related 2AR agonists such as lisuride lack comparable psychoactive properties. Why only certain 2AR agonists are hallucinogens and which neural circuits mediate their effects are poorly understood. By genetically expressing 2AR only in cortex, we show that 2AR-regulated pathways on cortical neurons are sufficient to mediate the signaling pattern and behavioral response to hallucinogens. Hallucinogenic and nonhallucinogenic 2AR agonists both regulate signaling in the same 2AR-expressing cortical neurons. However, the signaling and behavioral responses to the hallucinogens are distinct. While lisuride and LSD both act at 2AR expressed by cortex neurons to regulate phospholipase C, LSD responses also involve pertussis toxin-sensitive heterotrimeric G(i/o) proteins and Src. These studies identify the long-elusive neural and signaling mechanisms responsible for the unique effects of hallucinogens.

keywords:
Pyramidal Cells, Cerebral Cortex, Cells, Cultured, Animals, Mice, Knockout, Mice, Amphetamines, Lisuride, Ketanserin, Receptors, Dopamine D1, Receptors, Dopamine D2, Receptor, Serotonin, 5-HT2A, Serotonin Antagonists, Hallucinogens, Autoradiography, In Situ Hybridization, Fluorescence, Reverse Transcriptase Polymerase Chain Reaction, Behavior, Animal, Electrophysiology, Signal Transduction, Binding, Competitive, Male, Serotonin Receptor Agonists

raw_json:
{"europe_pmc_id":"17270739","source":"MED","pub_type":null,"publisher":null,"importer":"Europe PMC"}


authors: Majdanik S, Borowiak K, Brzezńska M, Machoy-Mokrzyńska A.
publication_date: 2006-12-31
pubmed_id: 20143700
source_url: https://europepmc.org/article/MED/20143700
substance_tags: psilocybin,psilocin
topic_tags: Mechanism of Action,Receptor Pharmacology,Healthcare Workers
study_type: Other
source_name: Europe PMC
publication_status: published
date_added: 2026-07-01 06:54:14
last_checked: 2026-07-01 11:22:06
title:
[Concentration of selected microelements in blood serum of rats exposed to the action of psilocin and phenylethylamine].

abstract:
Natural hallucinogens (including Psilocybe mushrooms) became popular in Europe since the nineties. They have been in the focus of clinicians interest for years because of their biological effects. Mechanism of action of these hallucinogens, both Psilocin and Psilocibin, is based on the physiological structure similarity to human neurotransmitters as serotonin and catecholamines. One of the previous works indicated the possibility of the cardiotoxic action of the Psilocibin mushroom, effecting in anoxemic heart laesure. To verify the hypothesis of the Psilocibin-like myocardial damage wide experimental programme was designed. In the present work we introduce some results concerning magnesium, calcium, natrium, kalium and chloride plasma concentration in rats subjected subchronicly to psilocin and phenylethylamine. Basing on the obtained results, it can be stated that subchronic intoxication with natural hallucinogens may disturb magnesium balance without significantly effecting other microelements.

keywords:
Animals, Rats, Rats, Wistar, Chlorides, Sodium, Calcium, Magnesium, Phenethylamines, Hallucinogens, Water-Electrolyte Balance, Male, Psilocybin

raw_json:
{"europe_pmc_id":"20143700","source":"MED","pub_type":null,"publisher":null,"importer":"Europe PMC"}


title: 5-Year trends in use of hallucinogens and other adjunct drugs among UK dance drug users.
authors: McCambridge J, Winstock A, Hunt N, Mitcheson L.
publication_date: 2006-12-31
doi: 10.1159/000095816
pubmed_id: 17172780
source_url: https://doi.org/10.1159/000095816
substance_tags: psilocybin
topic_tags: Observational Study
study_type: Observational Study
source_name: Europe PMC
publication_status: published
date_added: 2026-07-01 06:54:14
last_checked: 2026-07-01 11:22:07
abstract:
AimsTo describe and assess trends in the use of hallucinogens and other adjunct drugs over a 5-year period.DesignRepeated-measures cross-sectional survey.Setting and participantsAnnual magazine-based survey targeting people who use drugs in dance contexts.MeasurementsLifetime use prevalence (ever used); age of first use; current use prevalence (any use within the last month), and extent of use within the last month (number of days used) for LSD, psilocybin, ketamine, GHB and nitrates.FindingsPrevalence increases for psilocybin, ketamine, GHB and nitrates use have been detected, with a sharp recent rise in current psilocybin use in 2002-2003 contrasting with more gradual and comprehensive evidence of increased ketamine use throughout the period 1999-2003. The declining prevalence of LSD use in general population surveys is replicated in this sentinel population study.ConclusionsThe rise in prevalence of hallucinogen and other adjunct drugs identified among dance drug users may be mirrored by wider prevalence increases among young people with a consequent need to study these trends carefully and to develop effective interventions, where required.

keywords:
Humans, Substance-Related Disorders, N-Methyl-3,4-methylenedioxyamphetamine, Ketamine, Lysergic Acid Diethylamide, Hallucinogens, Incidence, Prevalence, Cross-Sectional Studies, Adult, Female, Male, United Kingdom, Psilocybin

raw_json:
{"europe_pmc_id":"17172780","source":"MED","pub_type":null,"publisher":null,"importer":"Europe PMC"}


title: Effects of psilocybin on time perception and temporal control of behaviour in humans.
authors: Wittmann M, Carter O, Hasler F, Cahn BR, Grimberg U, Spring P, Hell D, Flohr H, Vollenweider FX.
publication_date: 2006-05-18
doi: 10.1177/0269881106065859
pubmed_id: 16714323
source_url: https://doi.org/10.1177/0269881106065859
substance_tags: psilocybin
topic_tags: Receptor Pharmacology,Consciousness,Drug Interactions
study_type: Other
source_name: Europe PMC
publication_status: published
date_added: 2026-07-01 06:54:14
last_checked: 2026-07-01 11:22:06
abstract:
Hallucinogenic psilocybin is known to alter the subjective experience of time. However, there is no study that systematically investigated objective measures of time perception under psilocybin. Therefore, we studied dose-dependent effects of the serotonin (5-HT)2A/1A receptor agonist psilocybin (4-phosphoryloxy-N, N-dimethyltryptamine) on temporal processing, employing tasks of temporal reproduction, sensorimotor synchronization and tapping tempo. To control for cognitive and subjective changes, we assessed spatial working memory and conscious experience. Twelve healthy human volunteers were tested under placebo, medium (115 microg/kg), and high (250 microg/kg) dose conditions, in a double-blind experimental design. Psilocybin was found to significantly impair subjects' ability to (1) reproduce interval durations longer than 2.5 sec, (2) to synchronize to inter-beat intervals longer than 2 sec and (3) caused subjects to be slower in their preferred tapping rate. These objective effects on timing performance were accompanied by working-memory deficits and subjective changes in conscious state, namely increased reports of 'depersonalization' and 'derealization' phenomena including disturbances in subjective 'time sense.' Our study is the first to systematically assess the impact of psilocybin on timing performance on standardized measures of temporal processing. Results indicate that the serotonin system is selectively involved in duration processing of intervals longer than 2 to 3 seconds and in the voluntary control of the speed of movement. We speculate that psilocybin's selective disruption of longer intervals is likely to be a product of interactions with cognitive dimensions of temporal processing -presumably via 5-HT2A receptor stimulation.

keywords:
Humans, Dopamine Agonists, Hallucinogens, Analysis of Variance, Double-Blind Method, Depersonalization, Memory, Space Perception, Time Perception, Psychomotor Performance, Periodicity, Dose-Response Relationship, Drug, Time Factors, Reference Values, Adult, Female, Male, Serotonin 5-HT1 Receptor Agonists, Serotonin 5-HT2 Receptor Agonists, Psilocybin

raw_json:
{"europe_pmc_id":"16714323","source":"MED","pub_type":null,"publisher":null,"importer":"Europe PMC"}


title: The adverse effects of hallucinogens from intramural perspective.
authors: Frecska E, Luna LE.
publication_date: 2006-11-30
pubmed_id: 17211054
source_url: https://europepmc.org/article/MED/17211054
keywords: Humans, Poisoning, Hallucinogens, Emergency Treatment, Personality, Perception, Drug Interactions
substance_tags: psilocybin
topic_tags: Personality Change,Clinical Trial,Review Article,Safety,Drug Interactions
study_type: Clinical Trial
source_name: Europe PMC
publication_status: published
date_added: 2026-07-01 06:54:14
last_checked: 2026-07-01 11:22:07
abstract:
UnlabelledVery recently, after a long-lasting, worldwide moratorium on research of hallucinogenic agents, a good number of advanced countries have been revising their position, and start to approve testing the physiological and therapeutic effects of hallucinogens in human subjects. The purpose of this article is to review safety information available in the literature on hallucinogen use, and sort out those data from the reported complications of their abuse. Because of prohibitory regulations of the last 35 years, there are difficulties in achieving this kind of evaluation. Our approach has to be broad, and at times retrospective, in contrast to the well-controlled, focused, prospective design of the premarketing trials of legal drugs. The article summarizes the analyses in anticipation of supportive regulatory changes for the use of hallucinogens in well controlled studies and strictly supervised clinical trials.Keywordsadverse effects, ayahuasca, N,N-dimethyltryptamine, hallucinogenic agents, ibogaine, lysergic acid diethylamide, N-methyl-3,4-methylenedioxyamphetamine, psilocybin, therapeutic use.

raw_json:
{"europe_pmc_id":"17211054","source":"MED","pub_type":null,"publisher":null,"importer":"Europe PMC"}


title: Detection and determination of abused hallucinogens in biological material.
authors: Ondra P, Zedníková K, Válka I.
publication_date: 2006-11-30
pubmed_id: 17159796
source_url: https://europepmc.org/article/MED/17159796
substance_tags: psilocin
topic_tags: Toxicity
study_type: Qualitative Study
source_name: Europe PMC
publication_status: published
date_added: 2026-07-01 06:54:14
last_checked: 2026-07-01 11:22:07
abstract:
ObjectivesUntil recently, routine toxicological analysis of some hallucinogens in biological material posed problems which were only resolved after the introduction of modern analytic systems into toxicological laboratories. The most frequent hallucinogens in clinical and forensic toxicology can be grouped as: cannabinoids, tropane alkaloids, N,N-dimethyltryptamine derivatives and synthetic or semisynthetic hallucinogens.Methods & resultsThere are several methods currently used for their analysis. Immunoassay analysis of abused hallucinogens is limited to the cannabinoids. Thin layer chromatography (TLC) is able to detect higher concentrations of 1-nor-delta- 9-tetrahydrocannabinol-9-carboxylic acid (THC-COOH), tropane alkaloids (atropine and scopolamine) and ketamine (synthetic hallucinogen) in urine but for lower concentrations and for some other substances it lacks sensitivity. A reliable solution to the demand for specific and sensitive analysis of hallucinogens in biological material is gas chromatography - mass spectrometry (GC-MS). Thus, at present, analysis of cannabinoids, tropane alkaloids, ketamine as well as psilocin (N,N-dimethyltryptamine derivative) is well-managed.ConclusionsThe introduction of GC-MS systems appears to be indispensable for satisfactory qualitative and quantitative analysis of drugs of abuse, particularly hallucinogens in biological material.

keywords:
Humans, Hallucinogens, Chromatography, Thin Layer, Substance Abuse Detection, Models, Biological, Gas Chromatography-Mass Spectrometry, Forensic Toxicology

raw_json:
{"europe_pmc_id":"17159796","source":"MED","pub_type":null,"publisher":null,"importer":"Europe PMC"}


authors: Maruyama T, Kawahara N, Yokoyama K, Makino Y, Fukiharu T, Goda Y.
publication_date: 2005-12-14
doi: 10.1016/j.forsciint.2004.10.028
pubmed_id: 16343833
source_url: https://doi.org/10.1016/j.forsciint.2004.10.028
substance_tags: psilocybin,psilocin
topic_tags: General
study_type: Other
source_name: Europe PMC
publication_status: published
date_added: 2026-07-01 06:54:14
last_checked: 2026-07-01 11:22:06
title:
Phylogenetic relationship of psychoactive fungi based on rRNA gene for a large subunit and their identification using the TaqMan assay (II).

abstract:
"Magic mushroom (MM)" is the name most commonly given to psychoactive fungi containing the hallucinogenic components: psilocin (1) and psilocybin (2). We investigated the rRNA gene (internal transcribed spacer (ITS) and large subunit (LSU)) of two Panaeolus species and four Psilocybe species fungi (of these, two are non-psilocybin species). On the basis of sequence alignment, we improved the identification system developed in our previous study. In this paper, we describe the new system capable of distinguishing MMs from non-psilocybin Psilocybe species, its application data and the phylogeny of MM species.

keywords:
Humans, Agaricales, Substance-Related Disorders, DNA, Fungal, RNA, Fungal, Hallucinogens, Polymerase Chain Reaction, Substance Abuse Detection, Phylogeny, Base Sequence, Genes, rRNA, Drug and Narcotic Control, Molecular Sequence Data, Japan, Gas Chromatography-Mass Spectrometry, Psilocybin

raw_json:
{"europe_pmc_id":"16343833","source":"MED","pub_type":null,"publisher":null,"importer":"Europe PMC"}


title: Safety, tolerability, and efficacy of psilocybin in 9 patients with obsessive-compulsive disorder.
authors: Moreno FA, Wiegand CB, Taitano EK, Delgado PL.
publication_date: 2006-10-31
doi: 10.4088/jcp.v67n1110
pubmed_id: 17196053
source_url: https://doi.org/10.4088/jcp.v67n1110
substance_tags: psilocybin
topic_tags: Anxiety,OCD,Chronic Pain,Receptor Pharmacology,Safety,Drug Interactions
study_type: Other
source_name: Europe PMC
publication_status: published
date_added: 2026-07-01 06:54:14
last_checked: 2026-07-01 11:22:06
abstract:
BackgroundAnecdotal reports suggest that psychedelic agents may relieve symptoms of obsessive-compulsive disorder (OCD). This modified double-blind study investigated the safety, tolerability, and clinical effects of psilocybin, a potent 5-HT(1A) and 5-HT(2A/2C) agonist, in patients with OCD.MethodNine subjects with DSM-IV-defined OCD and no other current major psychiatric disorder participated in up to 4 single-dose exposures to psilocybin in doses ranging from sub-hallucinogenic to frankly hallucinogenic. Low (100 microg/kg), medium (200 microg/kg), and high (300 microg/kg) doses were assigned in that order, and a very low dose (25 microg/kg) was inserted randomly and in double-blind fashion at any time after the first dose. Testing days were separated by at least 1 week. Each session was conducted over an 8-hour period in a controlled environment in an outpatient clinic; subjects were then transferred to a psychiatric inpatient unit for overnight observation. The Yale-Brown Obsessive Compulsive Scale (YBOCS) and a visual analog scale measuring overall obsessive-compulsive symptom severity were administered at 0, 4, 8, and 24 hours post-ingestion. The Hallucinogen Rating Scale was administered at 8 hours, and vital signs were recorded at 0, 1, 4, 8, and 24 hours after ingestion. The study was conducted from November 2001 to November 2004.ResultsNine subjects were administered a total of 29 psilocybin doses. One subject experienced transient hypertension without relation to anxiety or somatic symptoms, but no other significant adverse effects were observed. Marked decreases in OCD symptoms of variable degrees were observed in all subjects during 1 or more of the testing sessions (23%-100% decrease in YBOCS score). Repeated-measures analysis of variance for all YBOCS values revealed a significant main effect of time on Wilks lambda (F = 9.86, df = 3,3; p =.046), but no significant effect of dose (F = 2.25, df = 3,3; p =.261) or interaction of time and dose (F = 0.923, df = 9,45; p =.515). Improvement generally lasted past the 24-hour timepoint.ConclusionsIn a controlled clinical environment, psilocybin was safely used in subjects with OCD and was associated with acute reductions in core OCD symptoms in several subjects.

keywords:
Humans, Hallucinogens, Pain Measurement, Treatment Outcome, Severity of Illness Index, Analysis of Variance, Double-Blind Method, Obsessive-Compulsive Disorder, Adult, Middle Aged, Female, Male, Psilocybin

raw_json:
{"europe_pmc_id":"17196053","source":"MED","pub_type":null,"publisher":null,"importer":"Europe PMC"}


title: [Chronic cluster headache: Response to psilocybin].
authors: Sempere AP, Berenguer-Ruiz L, Almazán F.
publication_date: 2006-10-31
doi: 10.33588/rn.4309.2006432
pubmed_id: 17072817
source_url: https://doi.org/10.33588/rn.4309.2006432
keywords: Humans, Cluster Headache, Middle Aged, Male, Psilocybin
substance_tags: psilocybin
topic_tags: Headache / Migraine
study_type: Other
source_name: Europe PMC
publication_status: published
date_added: 2026-07-01 06:54:14
last_checked: 2026-07-01 11:22:07
raw_json:
{"europe_pmc_id":"17072817","source":"MED","pub_type":null,"publisher":null,"importer":"Europe PMC"}


authors: Griffiths RR, Richards WA, McCann U, Jesse R.
publication_date: 2006-07-06
doi: 10.1007/s00213-006-0457-5
pubmed_id: 16826400
source_url: https://doi.org/10.1007/s00213-006-0457-5
substance_tags: psilocybin
topic_tags: Anxiety,Spirituality,Mystical Experience,Observational Study
study_type: Observational Study
source_name: Europe PMC
publication_status: published
date_added: 2026-07-01 06:54:14
last_checked: 2026-07-01 11:22:06
title:
Psilocybin can occasion mystical-type experiences having substantial and sustained personal meaning and spiritual significance.

abstract:
RationaleAlthough psilocybin has been used for centuries for religious purposes, little is known scientifically about its acute and persisting effects.ObjectivesThis double-blind study evaluated the acute and longer-term psychological effects of a high dose of psilocybin relative to a comparison compound administered under comfortable, supportive conditions.Materials and methodsThe participants were hallucinogen-naïve adults reporting regular participation in religious or spiritual activities. Two or three sessions were conducted at 2-month intervals. Thirty volunteers received orally administered psilocybin (30 mg/70 kg) and methylphenidate hydrochloride (40 mg/70 kg) in counterbalanced order. To obscure the study design, six additional volunteers received methylphenidate in the first two sessions and unblinded psilocybin in a third session. The 8-h sessions were conducted individually. Volunteers were encouraged to close their eyes and direct their attention inward. Study monitors rated volunteers' behavior during sessions. Volunteers completed questionnaires assessing drug effects and mystical experience immediately after and 2 months after sessions. Community observers rated changes in the volunteer's attitudes and behavior.ResultsPsilocybin produced a range of acute perceptual changes, subjective experiences, and labile moods including anxiety. Psilocybin also increased measures of mystical experience. At 2 months, the volunteers rated the psilocybin experience as having substantial personal meaning and spiritual significance and attributed to the experience sustained positive changes in attitudes and behavior consistent with changes rated by community observers.ConclusionsWhen administered under supportive conditions, psilocybin occasioned experiences similar to spontaneously occurring mystical experiences. The ability to occasion such experiences prospectively will allow rigorous scientific investigations of their causes and consequences.

keywords:
Humans, Substance-Related Disorders, Lysergic Acid Diethylamide, Hallucinogens, Cross-Over Studies, Double-Blind Method, Affect, Spirituality, Blood Pressure, Heart Rate, Adult, Female, Male, Surveys and Questionnaires, Psilocybin

raw_json:
{"europe_pmc_id":"16826400","source":"MED","pub_type":null,"publisher":null,"importer":"Europe PMC"}


title: Response of cluster headache to psilocybin and LSD.
authors: Sewell RA, Halpern JH, Pope HG.
publication_date: 2006-05-31
doi: 10.1212/01.wnl.0000219761.05466.43
pubmed_id: 16801660
source_url: https://doi.org/10.1212/01.wnl.0000219761.05466.43
substance_tags: psilocybin
topic_tags: Headache / Migraine
study_type: Other
source_name: Europe PMC
publication_status: published
date_added: 2026-07-01 06:54:14
last_checked: 2026-07-01 11:22:06
abstract:
The authors interviewed 53 cluster headache patients who had used psilocybin or lysergic acid diethylamide (LSD) to treat their condition. Twenty-two of 26 psilocybin users reported that psilocybin aborted attacks; 25 of 48 psilocybin users and 7 of 8 LSD users reported cluster period termination; 18 of 19 psilocybin users and 4 of 5 LSD users reported remission period extension. Research on the effects of psilocybin and LSD on cluster headache may be warranted.

keywords:
Humans, Cluster Headache, Lysergic Acid Diethylamide, Hallucinogens, Treatment Outcome, Severity of Illness Index, Retrospective Studies, Adult, Middle Aged, Female, Male, Psilocybin

raw_json:
{"europe_pmc_id":"16801660","source":"MED","pub_type":null,"publisher":null,"importer":"Europe PMC"}


title: Values and beliefs of psychedelic drug users: a cross-cultural study.
authors: Lerner M, Lyvers M.
publication_date: 2006-05-31
doi: 10.1080/02791072.2006.10399838
pubmed_id: 16903453
source_url: https://doi.org/10.1080/02791072.2006.10399838
substance_tags: psilocybin
topic_tags: Emotional Processing,Spirituality,Mystical Experience
study_type: Other
source_name: Europe PMC
publication_status: published
date_added: 2026-07-01 06:54:14
last_checked: 2026-07-01 11:22:07
abstract:
Psychedelic drugs such as LSD and psilocybin are often claimed to be capable of inducing life-changing experiences described as mystical or transcendental, especially if high doses are taken. The present study examined possible enduring effects of such experiences by comparing users of psychedelic drugs (n = 88), users of nonpsychedelic illegal drugs (e.g., marijuana, amphetamines) (n = 29) and non illicit drug-using social drinkers (n = 66) on questionnaire measures of values, beliefs and emotional empathy. Samples were obtained from Israel (n = 110) and Australia (n = 73) in a cross-cultural comparison to see if values associated with psychedelic drug use transcended culture of origin. Psychedelic users scored significantly higher on mystical beliefs (e.g., oneness with God and the universe) and life values of spirituality and concern for others than the other groups, and lower on the value of financial prosperity, irrespective of culture of origin. Users of nonpsychedelic illegal drugs scored significantly lower on a measure of coping ability than both psychedelic users and non illicit drug users. Both groups of illegal drug users scored significantly higher on empathy than non illicit drug users. Results are discussed in the context of earlier findings from Pahnke (1966) and Doblin (1991) of the transformative effect of psychedelic experiences, although the possibility remains that present findings reflect predrug characteristics of those who chose to take psychedelic drugs rather than effects of the drugs themselves.

keywords:
Humans, Substance-Related Disorders, Hallucinogens, Health Behavior, Social Values, Culture, Cross-Cultural Comparison, Adult, Aged, Middle Aged, Israel, Australia

raw_json:
{"europe_pmc_id":"16903453","source":"MED","pub_type":null,"publisher":null,"importer":"Europe PMC"}


title: Patterns of simultaneous polysubstance use in drug using university students.
authors: Barrett SP, Darredeau C, Pihl RO.
publication_date: 2006-05-31
doi: 10.1002/hup.766
pubmed_id: 16783813
source_url: https://doi.org/10.1002/hup.766
substance_tags: psilocybin
topic_tags: Addiction,Adolescents
study_type: Other
source_name: Europe PMC
publication_status: published
date_added: 2026-07-01 06:54:14
last_checked: 2026-07-01 11:22:07
abstract:
Simultaneous polysubstance use (SPU) is a common phenomenon, yet little is known about how various substances are used with one another. In the present study 149 drug-using university students completed structured interviews about their use of various substances. For each substance ever used, participants provided details about the type, order and amount of all substances co-administered during its most recent administration. Alcohol, tobacco and cannabis were frequently co-administered with each other and with all other substances. Chi-squared tests revealed that when alcohol was used in combination with any of cannabis, psilocybin, MDMA, cocaine, amphetamine, methylphenidate (ps < 0.01) or LSD (p < 0.05) its initial use preceded the administration of the other substance. Paired samples t-tests revealed that when alcohol was used with cocaine (p < 0.01) or methylphenidate (p < 0.05) it was ingested in greater quantities than when used in their absence. Patterns of cannabis use were not systematically related to other substances administered. Finally, using one-sample t-tests, tobacco use was demonstrated to be increased relative to 'sober' smoking rates when used with alcohol, cannabis, psilocybin, MDMA, cocaine, amphetamine (ps < 0.001), LSD (p < 0.01) or methylphenidate (p < 0.05). Results suggest that many substances are routinely used in a SPU context and that the pattern in which a substance is used may be related to other substances co-administered.

keywords:
Humans, Substance-Related Disorders, Alcoholism, Marijuana Abuse, Ethanol, N-Methyl-3,4-methylenedioxyamphetamine, Cocaine, Smoking, Students, Universities, Adolescent, Adult, Female, Male

raw_json:
{"europe_pmc_id":"16783813","source":"MED","pub_type":null,"publisher":null,"importer":"Europe PMC"}


authors: Jensen N, Gartz J, Laatsch H.
publication_date: 2006-04-27
doi: 10.1055/s-2006-931576
pubmed_id: 16673333
source_url: https://doi.org/10.1055/s-2006-931576
keywords: Agaricales, Tryptamines, Organophosphorus Compounds
substance_tags: psilocybin
topic_tags: Receptor Pharmacology
study_type: Other
source_name: Europe PMC
publication_status: published
date_added: 2026-07-01 06:54:14
last_checked: 2026-07-01 11:22:06
title:
Aeruginascin, a trimethylammonium analogue of psilocybin from the hallucinogenic mushroom Inocybe aeruginascens.

abstract:
The hallucinogenic mushroom Inocybe aeruginascens contains several typical Psilocybe alkaloids including psilocybin. We have now elucidated the structure of a further indole derivative named aeruginascin as the quaternary ammonium compound N, N, N-trimethyl-4-phosphoryloxytryptamine. Aeruginascin is closely related to the frog skin toxin bufotenidine (5-HTQ), a potent 5-HT3 receptor agonist, and has been found exclusively in Inocybe aeruginascens so far.

raw_json:
{"europe_pmc_id":"16673333","source":"MED","pub_type":null,"publisher":null,"importer":"Europe PMC"}


title: Can mushrooms help save the world? Interview by Bonnie J. Horrigan.
authors: Stamets P.
publication_date: 2006-02-28
doi: 10.1016/j.explore.2005.12.011
pubmed_id: 16781630
source_url: https://doi.org/10.1016/j.explore.2005.12.011
keywords: Humans, Agaricales, Anti-Bacterial Agents, Phytotherapy
substance_tags: psilocybin
topic_tags: General
study_type: Other
source_name: Europe PMC
publication_status: published
date_added: 2026-07-01 06:54:14
last_checked: 2026-07-01 11:22:07
abstract:
Paul Stamets, founder and director of Fungi Perfecti, LLC., and director of the Fungi Perfecti Research Laboratories (www.fungi.com), has been a mycologist and mushroom enthusiast for more than 30 years. A pioneer in the cultivation of edible and medicinal mushrooms, he is credited with the discovery of four new mushroom species. Stamets is the author of five books on mushroom cultivation, use, and identification, including MycoMedicinals: An Informational Treatise on Mushrooms; Psilocybin Mushrooms of the World; Growing Gourmet and Medicinal Mushrooms; Mushroom Cultivator; Psilocybe Mushrooms & Their Allies; and his most recent one Mycelium Running: How Mushrooms Can Help Save the World. Stamets holds a vision of a deeply interconnected world environment and firmly believes that a greater knowledge of fungi can solve many of the world's pollution problems as well as some of the world's health problems. He has a strong interest in saving the old growth forests of the Pacific Northwest where many ancient species of mushrooms can be found. A dedicated explorer with a passion to preserve, protect, and clone as many ancestral strains of mushrooms as possible, he was the 1998 recipient of the Collective Heritage Institute's Bioneers Award and the 1999 recipient of the Founder of a New Northwest Award from the Pacific Rim Association of Resource Conservation and Development Councils. EXPLORE interviewed Stamets at his home and mushroom farms near Seattle, Washington, in the summer of 2005.

raw_json:
{"europe_pmc_id":"16781630","source":"MED","pub_type":null,"publisher":null,"importer":"Europe PMC"}


publication_date: 2005-11-30
doi: 10.1097/00063110-200512000-00011
pubmed_id: 16276262
source_url: https://pubmed.ncbi.nlm.nih.gov/16276262/
substance_tags: psilocybin
topic_tags: Adverse Events
study_type: Other
source_name: PubMed
publication_status: published
date_added: 2026-07-01 06:54:14
last_checked: 2026-07-01 11:20:41
raw_json: {"pubmed_id":"16276262"}
title:
Severe rhabdomyolysis, acute renal failure and posterior encephalopathy after 'magic mushroom' abuse.

authors:
Bickel M, Ditting T, Watz H, Roesler A, Weidauer S, Jacobi V, Gueller S, Betz C, Fichtlscherer S, Stein J

abstract:
We report the case of a 25-year-old, hepatitis C-infected man, who presented with severe rhabdomyolysis and acute renal failure, and later developed posterior encephalopathy with cortical blindness after the ingestion of magic mushrooms. Conventional respiratory and cardiovascular support including mechanical ventilation, continuous veno-venous hemodialysis and corticosteroids led to improvement and the patient recovered completely over the following months. Magic mushrooms are becoming increasingly fashionable among drug users, as they are believed to be more harmless than other hallucinogenic designer drugs. So far, little is known about their possible severe side effects.

journal:
European journal of emergency medicine : official journal of the European Society for Emergency Medicine


authors: Gouzoulis-Mayfrank E, Heekeren K, Neukirch A, Stoll M, Stock C, Obradovic M, Kovar KA.
publication_date: 2005-10-31
doi: 10.1055/s-2005-916185
pubmed_id: 16342002
source_url: https://doi.org/10.1055/s-2005-916185
substance_tags: psilocybin
topic_tags: Receptor Pharmacology,Healthy Volunteers
study_type: Other
source_name: Europe PMC
publication_status: published
date_added: 2026-07-01 06:54:14
last_checked: 2026-07-01 11:22:07
title:
Psychological effects of (S)-ketamine and N,N-dimethyltryptamine (DMT): a double-blind, cross-over study in healthy volunteers.

abstract:
IntroductionPharmacological challenges with hallucinogens are used as models for psychosis in experimental research. The state induced by glutamate antagonists such as phencyclidine (PCP) is often considered as a more appropriate model of psychosis than the state induced by serotonergic hallucinogens such as lysergic acid diethylamide (LSD), psilocybin and N,N-dimethyltryptamine (DMT). However, so far, the psychological profiles of the two types of hallucinogenic drugs have never been studied directly in an experimental within-subject design.MethodsFifteen healthy volunteers were included in a double-blind, cross-over study with two doses of the serotonin 5-HT2A agonist DMT and the glutamate N-methyl-D-aspartate (NMDA) antagonist (S)-ketamine.ResultsData are reported for nine subjects who completed both experimental days with both doses of the two drugs. The intensity of global psychological effects was similar for DMT and (S)-ketamine. However, phenomena resembling positive symptoms of schizophrenia, particularly positive formal thought disorder and inappropriate affect, were stronger after DMT. Phenomena resembling negative symptoms of schizophrenia, attention deficits, body perception disturbances and catatonia-like motor phenomena were stronger after (S)-ketamine.DiscussionThe present study suggests that the NMDA antagonist model of psychosis is not overall superior to the serotonin 5-HT2A agonist model. Rather, the two classes of drugs tend to model different aspects or types of schizophrenia. The NMDA antagonist state may be an appropriate model for psychoses with prominent negative and possibly also catatonic features, while the 5-HT2A agonist state may be a better model for psychoses of the paranoid type.

keywords:
Humans, Hallucinations, N,N-Dimethyltryptamine, Ketamine, Receptors, N-Methyl-D-Aspartate, Excitatory Amino Acid Antagonists, Hallucinogens, Infusions, Intravenous, Injections, Intravenous, Cross-Over Studies, Double-Blind Method, Cognition, Psychiatric Status Rating Scales, Psychometrics, Schizophrenic Psychology, Dose-Response Relationship, Drug, Stereoisomerism, Adult, Middle Aged, Female, Male

raw_json:
{"europe_pmc_id":"16342002","source":"MED","pub_type":null,"publisher":null,"importer":"Europe PMC"}


title: SAR of psilocybin analogs: discovery of a selective 5-HT2C agonist.
authors: Sard H, Kumaran G, Morency C, Roth BL, Toth BA, He P, Shuster L.
publication_date: 2005-09-30
doi: 10.1016/j.bmcl.2005.06.104
pubmed_id: 16061378
source_url: https://doi.org/10.1016/j.bmcl.2005.06.104
substance_tags: psilocybin,psilocin
topic_tags: OCD,Receptor Pharmacology,Animal Study
study_type: Animal Study
source_name: Europe PMC
publication_status: published
date_added: 2026-07-01 06:54:14
last_checked: 2026-07-01 11:22:05
abstract:
An SAR study of psilocybin and psilocin derivatives reveals that 1-methylpsilocin is a selective agonist at the h5-HT(2C) receptor. The corresponding phosphate derivative, 1-methylpsilocybin, shows efficacy in an animal model for obsessive-compulsive disorder, as does 4-fluoro-N,N-dimethyltryptamine. These results suggest a new area for development of novel 5-HT(2C) agonists with applications for drug discovery.

keywords:
Animals, Humans, Mice, Structure-Activity Relationship, Serotonin Receptor Agonists, Serotonin 5-HT2 Receptor Agonists, Psilocybin

raw_json:
{"europe_pmc_id":"16061378","source":"MED","pub_type":null,"publisher":null,"importer":"Europe PMC"}


authors: Carter OL, Burr DC, Pettigrew JD, Wallis GM, Hasler F, Vollenweider FX.
publication_date: 2005-09-30
doi: 10.1162/089892905774597191
pubmed_id: 16269092
source_url: https://doi.org/10.1162/089892905774597191
substance_tags: psilocybin
topic_tags: Receptor Pharmacology,Drug Interactions
study_type: Other
source_name: Europe PMC
publication_status: published
date_added: 2026-07-01 06:54:14
last_checked: 2026-07-01 11:22:06
title:
Using psilocybin to investigate the relationship between attention, working memory, and the serotonin 1A and 2A receptors.

abstract:
Increasing evidence suggests a link between attention, working memory, serotonin (5-HT), and prefrontal cortex activity. In an attempt to tease out the relationship between these elements, this study tested the effects of the hallucinogenic mixed 5-HT1A/2A receptor agonist psilocybin alone and after pretreatment with the 5-HT2A antagonist ketanserin. Eight healthy human volunteers were tested on a multiple-object tracking task and spatial working memory task under the four conditions: placebo, psilocybin (215 microg/kg), ketanserin (50 mg), and psilocybin and ketanserin. Psilocybin significantly reduced attentional tracking ability, but had no significant effect on spatial working memory, suggesting a functional dissociation between the two tasks. Pretreatment with ketanserin did not attenuate the effect of psilocybin on attentional performance, suggesting a primary involvement of the 5-HT1A receptor in the observed deficit. Based on physiological and pharmacological data, we speculate that this impaired attentional performance may reflect a reduced ability to suppress or ignore distracting stimuli rather than reduced attentional capacity. The clinical relevance of these results is also discussed.

keywords:
Humans, Ketanserin, Receptor, Serotonin, 5-HT1A, Receptor, Serotonin, 5-HT2A, Serotonin Antagonists, Hallucinogens, Chi-Square Distribution, Double-Blind Method, Memory, Short-Term, Space Perception, Psychomotor Performance, Attention, Reaction Time, Drug Interactions, Adult, Female, Male, Psilocybin

raw_json:
{"europe_pmc_id":"16269092","source":"MED","pub_type":null,"publisher":null,"importer":"Europe PMC"}


authors: Soyka M, Koch W, Möller HJ, Rüther T, Tatsch K.
publication_date: 2005-04-17
doi: 10.1007/s00406-005-0563-0
pubmed_id: 15834758
source_url: https://doi.org/10.1007/s00406-005-0563-0
substance_tags: psilocybin
topic_tags: General
study_type: Other
source_name: Europe PMC
publication_status: published
date_added: 2026-07-01 06:54:14
last_checked: 2026-07-01 11:22:07
title:
Hypermetabolic pattern in frontal cortex and other brain regions in unmedicated schizophrenia patients. Results from a FDG-PET study.

abstract:
We report results of a FDG-PET study in 10 patients with schizophrenia (6 unmedicated, 4 never medicated) and 12 healthy age-matched controls. The patients met ICD-10 and DSM-IV criteria for schizophrenia and all reported psychotic, "positive" symptoms when tested. Schizophrenic patients had higher absolute CMRGlu values in almost all quantified regions compared to normal subjects. Using the occipital cortex as the reference region patients showed a hyperfrontal metabolic pattern. Other significant regional differences were found with respect to thalamus, striatum and temporal cortex. The finding of a hyperfrontality in un- and never medicated psychotic schizophrenic patients must be discussed in the light of the psychopathological symptoms of patients when tested, a possible disruption of cortico-striato-thalamic feedback loops and recent findings of a hyperfrontality in experimentally induced psychosis (ketamine- and psilocybin-model of schizophrenia).

keywords:
Brain, Frontal Lobe, Humans, Fluorodeoxyglucose F18, Glucose, Positron-Emission Tomography, Schizophrenia, Schizophrenic Psychology, Adult, Middle Aged, Female, Male

raw_json:
{"europe_pmc_id":"15834758","source":"MED","pub_type":null,"publisher":null,"importer":"Europe PMC"}


title: Hallucinogen persisting perception disorder after psilocybin consumption: a case study.
authors: Espiard ML, Lecardeur L, Abadie P, Halbecq I, Dollfus S.
publication_date: 2005-07-31
doi: 10.1016/j.eurpsy.2005.04.008
pubmed_id: 15963699
source_url: https://doi.org/10.1016/j.eurpsy.2005.04.008
substance_tags: psilocybin
topic_tags: Depression,Anxiety,Addiction,Adolescents
study_type: Other
source_name: Europe PMC
publication_status: published
date_added: 2026-07-01 06:54:14
last_checked: 2026-07-01 11:22:07
abstract:
The recurrence of flashbacks without acute or chronic hallucinogen consumption has been recognized in the DSM IV criteria as the hallucinogen persisting perception disorder (HPPD). Perceptual disturbances may last for 5 years or more and represent a real psychosocial distress. We reported here a case of a 18-year-old young man presenting HPPD after a mixed intoxication with psylocibin and cannabis. This report shows symptomatic recurrences persisting more than 8 months. Various differential diagnoses were evoked and our therapeutic strategies were described.

keywords:
Humans, Perceptual Disorders, Recurrence, Sertraline, Risperidone, Antipsychotic Agents, Hallucinogens, Antidepressive Agents, Diagnosis, Differential, Marijuana Smoking, Anxiety, Depressive Disorder, Psychiatric Status Rating Scales, Time Factors, Social Behavior Disorders, Adolescent, Male, Psilocybin

raw_json:
{"europe_pmc_id":"15963699","source":"MED","pub_type":null,"publisher":null,"importer":"Europe PMC"}


authors: Carter OL, Pettigrew JD, Hasler F, Wallis GM, Liu GB, Hell D, Vollenweider FX.
publication_date: 2005-05-31
doi: 10.1038/sj.npp.1300621
pubmed_id: 15688092
source_url: https://doi.org/10.1038/sj.npp.1300621
substance_tags: psilocybin
topic_tags: Pharmacology,Mechanism of Action,Receptor Pharmacology,Consciousness
study_type: Clinical Trial
source_name: Europe PMC
publication_status: published
date_added: 2026-07-01 06:54:14
last_checked: 2026-07-01 11:22:06
title:
Modulating the rate and rhythmicity of perceptual rivalry alternations with the mixed 5-HT2A and 5-HT1A agonist psilocybin.

abstract:
Binocular rivalry occurs when different images are presented simultaneously to corresponding points within the left and right eyes. Under these conditions, the observer's perception will alternate between the two perceptual alternatives. Motivated by the reported link between the rate of perceptual alternations, symptoms of psychosis and an incidental observation that the rhythmicity of perceptual alternations during binocular rivalry was greatly increased 10 h after the consumption of LSD, this study aimed to investigate the pharmacology underlying binocular rivalry and to explore the connection between the timing of perceptual switching and psychosis. Psilocybin (4-phosphoryloxy-N,N-dimethyltryptamine, PY) was chosen for the study because, like LSD, it is known to act as an agonist at serotonin (5-HT)1A and 5-HT2A receptors and to produce an altered state sometimes marked by psychosis-like symptoms. A total of 12 healthy human volunteers were tested under placebo, low-dose (115 microg/kg) and high-dose (250 microg/kg) PY conditions. In line with predictions, under both low- and high-dose conditions, the results show that at 90 min postadministration (the peak of drug action), rate and rhythmicity of perceptual alternations were significantly reduced from placebo levels. Following the 90 min testing period, the perceptual switch rate successively increased, with some individuals showing increases well beyond pretest levels at the final testing, 360 min postadministration. However, as some subjects had still not returned to pretest levels by this time, the mean phase duration at 360 min was not found to differ significantly from placebo. Reflecting the drug-induced changes in rivalry phase durations, subjects showed clear changes in psychological state as indexed by the 5D-ASC (altered states of consciousness) rating scales. This study suggests the involvement of serotonergic pathways in binocular rivalry and supports the previously proposed role of a brainstem oscillator in perceptual rivalry alternations and symptoms of psychosis.

keywords:
Brain Stem, Raphe Nuclei, Humans, Serotonin, Hallucinogens, Affect, Consciousness, Memory, Short-Term, Perception, Visual Perception, Vision, Binocular, Dose-Response Relationship, Drug, Adult, Female, Male, Functional Laterality, Serotonin Receptor Agonists, Serotonin 5-HT1 Receptor Agonists, Serotonin 5-HT2 Receptor Agonists, Psilocybin

raw_json:
{"europe_pmc_id":"15688092","source":"MED","pub_type":null,"publisher":null,"importer":"Europe PMC"}


authors: Saito K, Toyo'oka T, Kato M, Fukushima T, Shirota O, Goda Y.
publication_date: 2005-01-05
doi: 10.1016/j.talanta.2004.11.031
pubmed_id: 18970021
source_url: https://doi.org/10.1016/j.talanta.2004.11.031
substance_tags: psilocybin
topic_tags: General
study_type: Clinical Trial
source_name: Europe PMC
publication_status: published
date_added: 2026-07-01 06:54:14
last_checked: 2026-07-01 11:22:06
title:
Determination of psilocybin in hallucinogenic mushrooms by reversed-phase liquid chromatography with fluorescence detection.

abstract:
The determination of psilocybin was carried out by reversed-phase liquid chromatography (HPLC) with fluorescence (FL) detection. Psilocybin was labeled with 5-dimethylaminonaphthalene-1-[N-(2-aminoethyl)]sulfonamide (DNS-ED) at 60 degrees C for 4h in the presence of 1-ethyl-3-(3-dimethylaminopropyl)-carbodiimide (EDC) as the activation reagent. The resulting derivative was separated on a Mightysil RP-18 GP column (150mmx4.6mm, i.d. 3mum) with the mixture of 50mM ammonium acetate (AcONH(4)) and CH(3)CN, and detected at 539nm (excitation at 321nm). The structure of the derivative was identified by HPLC-ESI-MS. A good linear relation of the calibration curve of psilocybin was observed under the proposed conditions for labeling, separation and detection. The quantification limit was 4.4ng in 1mg dried mushroom. The proposed procedure was successfully used for the determination of psilocybin in real samples. The contents of psilocybin in six magic mushrooms by the proposed HPLC-FL method were less than 20.0ng in 1mg dried samples.

raw_json:
{"europe_pmc_id":"18970021","source":"MED","pub_type":null,"publisher":null,"importer":"Europe PMC"}


title: [DNA and chemical analyses of commercial fly agaric-related products].
authors: Maruyama T, Kawahara N, Fukiharu T, Yokoyama K, Makino Y, Goda Y.
publication_date: 2005-03-31
doi: 10.3358/shokueishi.46.49
pubmed_id: 16018591
source_url: https://doi.org/10.3358/shokueishi.46.49
keywords: Amanita, Tryptamines, Harmine, DNA, Fungal, Base Sequence, Internet
substance_tags: psilocybin,psilocin
topic_tags: Mitochondrial Function
study_type: Other
source_name: Europe PMC
publication_status: published
date_added: 2026-07-01 06:54:14
last_checked: 2026-07-01 11:22:06
abstract:
Since June 6, 2002, psilocin and psilocybin-containing fungi (commonly called "magic mushrooms") have been regulated by the Narcotics and Psychotropics Control Law in Japan. However, various fly agaric-related products are now entering the Japanese market via the internet. In this study, fly agaric-related products available in this way were investigated for raw materials by DNA analysis and for additives by chemical analysis. Nucleotide sequence analysis of the mitochondrial 12S rDNA region suggested that these fly agaric-related products originate from A. muscaria or A. muscaria var. persicina. Furthermore, they were classified into three strains based on the ITS2-LSU nucleotide sequence. Harmine derivatives and/or tryptamine derivatives were detected in some of these products by LC/MS analysis. In accordance with this, the matK gene of Peganum harmala was found in all of the harmine derivative-containing samples.

raw_json:
{"europe_pmc_id":"16018591","source":"MED","pub_type":null,"publisher":null,"importer":"Europe PMC"}


title: Substance abuse on the college campus.
authors: Rimsza ME, Moses KS.
publication_date: 2005-01-31
doi: 10.1016/j.pcl.2004.10.008
pubmed_id: 15748936
source_url: https://doi.org/10.1016/j.pcl.2004.10.008
substance_tags: psilocybin
topic_tags: Addiction,Review Article
study_type: Review Article
source_name: Europe PMC
publication_status: published
date_added: 2026-07-01 06:54:14
last_checked: 2026-07-01 11:22:07
abstract:
Substance abuse is a major health and behavioral concern in college students. Alcohol and marijuana are the most commonly abused drugs on college campuses. Others include tobacco, 3,4-methylenedioxymethamphetamine, gamma-hydroxybutyrate, flunitrazepam (Rohypnol), lysergic acid, ketamine, methamphetamine, phencyclidine, cocaine, and psilocybin mushrooms. This article reviews the use of these drugs by college students. Substance use is a major contributing factor in poor academic performance and failure to successfully complete a college education.

keywords:
Humans, Substance-Related Disorders, Substance Abuse Detection, Students, Universities, Illicit Drugs

raw_json:
{"europe_pmc_id":"15748936","source":"MED","pub_type":null,"publisher":null,"importer":"Europe PMC"}


title: Response consistency in young adolescents' drug use self-reports: a recanting rate analysis.
authors: Percy A, McAlister S, Higgins K, McCrystal P, Thornton M
journal: Addiction (Abingdon, England)
publication_date: 2005-01-31
doi: 10.1111/j.1360-0443.2004.00943.x
pubmed_id: 15679748
source_url: https://pubmed.ncbi.nlm.nih.gov/15679748/
substance_tags: psilocybin
topic_tags: Addiction,Observational Study,Adolescents
study_type: Observational Study
source_name: PubMed
publication_status: published
date_added: 2026-07-01 06:54:14
last_checked: 2026-07-01 06:54:14
raw_json: {"pubmed_id":"15679748"}
abstract:
To assess the reliability of drug use reports by young respondents, this study examined the extent of recanting previous drug use reports within an ongoing longitudinal survey of adolescent drug use. Here, recanting was defined as a positive report of life-time drug use that was subsequently denied 1 year later. The covariates of recanting were also studied.
An ongoing longitudinal survey of young adolescents (Belfast Youth Development Study) in Northern Ireland.
Pencil and paper questionnaires were administered to pupils within participating schools.
Measures analysed included (a) recanting rates across 13 substances, (b) educational characteristics, (c) offending behaviour and (d) socio-economic status.
High levels of drug use recanting were identified, ranging from 7% of past alcohol use to 87% of past magic mushroom use. Recanting increased with the social stigma of the substance used. Denying past alcohol use was associated with being male, attending a catholic school, having positive attitudes towards school, having negative education expectations and not reporting any offending behaviour. Recanting alcohol intoxication was associated with being male and not reporting serious offending behaviour. Cannabis recanting was associated with having negative education expectations, receiving drugs education and not reporting serious offending behaviour.
The high levels of recanting uncovered cast doubts on the reliability of drug use reports from young adolescents. Failure to address this response error may lead to biased prevalence estimates, particularly within school surveys and drug education evaluation trials.


title: Hallucinogenic mushrooms.
authors: Schwartz RH, Smith DE.
publication_date: 1988-01-31
doi: 10.1177/000992288802700202
pubmed_id: 3338231
source_url: https://doi.org/10.1177/000992288802700202
substance_tags: psilocybin
topic_tags: Pharmacology,Review Article,Adolescents
study_type: Review Article
source_name: Europe PMC
publication_status: published
date_added: 2026-07-01 06:54:14
last_checked: 2026-07-01 11:22:07
raw_json: {"europe_pmc_id":"3338231","source":"MED","pub_type":null,"publisher":null,"importer":"Europe PMC"}
abstract:
Ingestion of mushrooms containing psilocybin produces hallucinogenic effects and has become a popular form of substance abuse among some adolescents and young adults. We have reviewed the medical literature on psilocybin mushrooms and describe current patterns of use, provide background material on the botony and pharmacology of these crude drugs, and report results of a small study on usage patterns among identified adolescent drug abusers. Among 174 adolescents already identified as substance abusers, 45 (26%) reported having used hallucinogenic mushrooms, frequently in conjunction with alcohol or other drugs. An average intake of 2-4 mushrooms was obtained for about +8, and led to intoxication for 5-6 hours. Mixing of intoxicants such as alcohol, marijuana, and psilocybin mushrooms was the rule. The acute adverse reactions may have been the result of drug synergy. Pediatricians should become aware of the specific patterns of the use of hallucinogenic drugs by adolescents and consider the possibility of such use when evaluating a delirious or psychotic adolescent.

keywords:
Humans, Mushroom Poisoning, Substance-Related Disorders, Lysergic Acid Diethylamide, Adolescent, Female, Male, Psilocybin


title: Psilocybin impairs high-level but not low-level motion perception.
authors: Carter OL, Pettigrew JD, Burr DC, Alais D, Hasler F, Vollenweider FX.
publication_date: 2004-07-31
doi: 10.1097/00001756-200408260-00023
pubmed_id: 15305143
source_url: https://doi.org/10.1097/00001756-200408260-00023
substance_tags: psilocybin
topic_tags: Receptor Pharmacology
study_type: Other
source_name: Europe PMC
publication_status: published
date_added: 2026-07-01 06:54:14
last_checked: 2026-07-01 11:22:06
abstract:
The hallucinogenic serotonin(1A&2A) agonist psilocybin is known for its ability to induce illusions of motion in otherwise stationary objects or textured surfaces. This study investigated the effect of psilocybin on local and global motion processing in nine human volunteers. Using a forced choice direction of motion discrimination task we show that psilocybin selectively impairs coherence sensitivity for random dot patterns, likely mediated by high-level global motion detectors, but not contrast sensitivity for drifting gratings, believed to be mediated by low-level detectors. These results are in line with those observed within schizophrenic populations and are discussed in respect to the proposition that psilocybin may provide a model to investigate clinical psychosis and the pharmacological underpinnings of visual perception in normal populations.

keywords:
Humans, Hallucinogens, Analysis of Variance, Photic Stimulation, Pattern Recognition, Visual, Motion Perception, Contrast Sensitivity, Choice Behavior, Psychophysics, Dose-Response Relationship, Drug, Adult, Female, Male, Psilocybin

raw_json:
{"europe_pmc_id":"15305143","source":"MED","pub_type":null,"publisher":null,"importer":"Europe PMC"}


authors: Scholey AB, Parrott AC, Buchanan T, Heffernan TM, Ling J, Rodgers J.
publication_date: 2004-05-31
doi: 10.1016/j.addbeh.2004.02.022
pubmed_id: 15135556
source_url: https://doi.org/10.1016/j.addbeh.2004.02.022
substance_tags: psilocybin
topic_tags: Addiction,Observational Study
study_type: Observational Study
source_name: Europe PMC
publication_status: published
date_added: 2026-07-01 06:54:14
last_checked: 2026-07-01 11:22:07
title:
Increased intensity of Ecstasy and polydrug usage in the more experienced recreational Ecstasy/MDMA users: a WWW study.

abstract:
Recreational Ecstasy/MDMA (3,4-methylenedioxymethamphetamine) users often take a variety of psychoactive drugs, but there is little empirical data on how these drug consumption patterns change with greater experience of Ecstasy. The aim of this study was to compare the polydrug usage patterns reported by non-Ecstasy users, novice Ecstasy users, moderate Ecstasy users, and heavy Ecstasy users. In a WWW study of 763 unpaid volunteers, 481 had never taken Ecstasy, whereas 282 reported they had taken it. The Ecstasy users comprised 109 novice users (1-9 occasions), 136 moderate Ecstasy users (10-99 occasions), and 36 heavy Ecstasy users (+100 occasions). Each participant also reported their experience with a range of other psychoactive drugs. The Ecstasy users reported significantly greater psychoactive drug usage than the non-Ecstasy users. The novice, moderate, and heavy Ecstasy users also differed significantly from each other in the use of cocaine, amphetamine, LSD, and psilocybin mushrooms, but not of alcohol, cannabis, or cigarettes/nicotine. Experienced Ecstasy users also took significantly more MDMA tablets on each occasion, and reported a higher maximum weekly intake. The increased use of Ecstasy is associated with more intensive patterns of Ecstasy/MDMA intake, and the greater use of illicit CNS stimulants and hallucinogens, but not of alcohol, nicotine, or cannabis. These results are discussed in the context of cross-tolerance and drug predisposition/preference.

keywords:
Humans, Substance-Related Disorders, N-Methyl-3,4-methylenedioxyamphetamine, Central Nervous System Stimulants, Hallucinogens, Psychotropic Drugs, Alcohol Drinking, Smoking, Internet, Adult, Female, Male, Surveys and Questionnaires, Illicit Drugs

raw_json:
{"europe_pmc_id":"15135556","source":"MED","pub_type":null,"publisher":null,"importer":"Europe PMC"}


title: Hallucinogens and dissociative agents naturally growing in the United States.
authors: Halpern JH.
publication_date: 2004-04-30
doi: 10.1016/j.pharmthera.2004.03.003
pubmed_id: 15163594
source_url: https://doi.org/10.1016/j.pharmthera.2004.03.003
substance_tags: psilocybin,psilocin
topic_tags: Review Article,Safety
study_type: Review Article
source_name: Europe PMC
publication_status: published
date_added: 2026-07-01 06:54:14
last_checked: 2026-07-01 11:22:06
abstract:
It is usually believed that drugs of abuse are smuggled into the United States or are clandestinely produced for illicit distribution. Less well known is that many hallucinogens and dissociative agents can be obtained from plants and fungi growing wild or in gardens. Some of these botanical sources can be located throughout the United States; others have a more narrow distribution. This article reviews plants containing N,N-dimethyltryptamine, reversible type A monoamine oxidase inhibitors (MAOI), lysergic acid amide, the anticholinergic drugs atropine and scopolamine, or the diterpene salvinorin-A (Salvia divinorum). Also reviewed are mescaline-containing cacti, psilocybin/psilocin-containing mushrooms, and the Amanita muscaria and Amanita pantherina mushrooms that contain muscimol and ibotenic acid. Dangerous misidentification is most common with the mushrooms, but even a novice forager can quickly learn how to properly identify and prepare for ingestion many of these plants. Moreover, through the ever-expanding dissemination of information via the Internet, this knowledge is being obtained and acted upon by more and more individuals. This general overview includes information on the geographical range, drug content, preparation, intoxication, and the special health risks associated with some of these plants. Information is also offered on the unique issue of when bona fide religions use such plants as sacraments in the United States. In addition to the Native American Church's (NAC) longstanding right to peyote, two religions of Brazilian origin, the Santo Daime and the Uniao do Vegetal (UDV), are seeking legal protection in the United States for their use of sacramental dimethyltryptamine-containing "ayahuasca."

keywords:
Fungi, Plants, N,N-Dimethyltryptamine, Ibotenic Acid, Muscimol, Hallucinogens, Dissociative Disorders, United States, Plant Development

raw_json:
{"europe_pmc_id":"15163594","source":"MED","pub_type":null,"publisher":null,"importer":"Europe PMC"}


title: Forensic analysis of hallucinogenic fungi: a DNA-based approach.
authors: Nugent KG, Saville BJ.
publication_date: 2004-02-29
doi: 10.1016/j.forsciint.2003.11.022
pubmed_id: 15036436
source_url: https://doi.org/10.1016/j.forsciint.2003.11.022
substance_tags: psilocybin,psilocin
topic_tags: General
study_type: Other
source_name: Europe PMC
publication_status: published
date_added: 2026-07-01 06:54:14
last_checked: 2026-07-01 11:22:06
abstract:
Hallucinogenic fungi synthesize two controlled substances, psilocin and psilocybin. Possession of the fungal species that contain these compounds is a criminal offence in North America. Some related species that are morphologically similar, do not contain the controlled substances. Therefore, unambiguous identification of fungi to the species level is critical in determining if a mushroom is illegal. We investigate a phylogenetic approach for the identification of species that contain the psychoactive compounds. We analyzed 35 North American specimens representing seven different genera of hallucinogenic and non-hallucinogenic mushrooms. We amplified and sequenced the internal transcribed spacer region of the rDNA (ITS-1) and a 5' portion of the nuclear large ribosomal subunit of rRNA (nLSU rRNA or 28S). ITS-1 locus sequence data was highly variable and produced a phylogenetic resolution that was not consistent with morphological identifications. In contrast, the nLSU rRNA data clustered isolates from the same species and separated hallucinogen containing and non-hallucinogen containing isolates into distinct clades. With this information, we propose an approach that combines the specificity of PCR detection and the resolving power of phylogenetic analysis to efficiently and unambiguously identify hallucinogenic fungal specimens for legal purposes.

keywords:
Humans, Agaricales, DNA, Fungal, DNA, Ribosomal Spacer, RNA, Ribosomal, DNA Primers, Hallucinogens, Polymerase Chain Reaction, Sequence Alignment, Phylogeny, Base Sequence, Forensic Sciences, Molecular Sequence Data, Psilocybin

raw_json:
{"europe_pmc_id":"15036436","source":"MED","pub_type":null,"publisher":null,"importer":"Europe PMC"}


authors: Fantegrossi WE, Woods JH, Winger G.
publication_date: 2004-02-29
doi: 10.1097/00008877-200403000-00007
pubmed_id: 15096915
source_url: https://doi.org/10.1097/00008877-200403000-00007
substance_tags: psilocybin
topic_tags: Addiction
study_type: Other
source_name: Europe PMC
publication_status: published
date_added: 2026-07-01 06:54:14
last_checked: 2026-07-01 11:22:07
title:
Transient reinforcing effects of phenylisopropylamine and indolealkylamine hallucinogens in rhesus monkeys.

abstract:
Relatively few studies have assessed the reinforcing effects of hallucinogenic compounds, and no such studies have attempted to engender contingent responding for these compounds in animals with behavioral histories that include experience with serotonergically mediated reinforcing effects. The objectives of the present study were to investigate the capacity of several hallucinogenic compounds to maintain self-administration behavior in rhesus monkeys with a previous history of 3,4-methylenedioxymethamphetamine (MDMA) self-administration, and to compare these effects across a range of doses of drugs from two structural classes (indolealkylamines and phenylisopropylamines). The results indicate that no compound generated reliable responding and that no subject ever self-administered 4-iodo-2,5-dimethoxyphenylisopropylamine (DOI) at rates above those engendered by contingent saline. However, 3 out of 4 subjects did respond at rates between 0.75 and 3.0 responses/s in one or more sessions where N,N-dimethyltryptamine (DMT), mescaline or psilocybin were available. During some of these sessions in which self-administration was maintained, animals earned a majority of all available infusions and appeared intoxicated by the end of the session. This pattern of transient self-administration may indicate that these compounds have weak reinforcing effects, or mixed reinforcing and aversive effects.

keywords:
Animals, Macaca mulatta, Amines, N,N-Dimethyltryptamine, Amphetamines, Mescaline, Cocaine, Indoles, Hallucinogens, Self Administration, Injections, Intravenous, Reinforcement Schedule, Dose-Response Relationship, Drug, Female, Male, Psilocybin, Reinforcement, Psychology

raw_json:
{"europe_pmc_id":"15096915","source":"MED","pub_type":null,"publisher":null,"importer":"Europe PMC"}


authors: Hasler F, Grimberg U, Benz MA, Huber T, Vollenweider FX.
publication_date: 2003-11-12
doi: 10.1007/s00213-003-1640-6
pubmed_id: 14615876
source_url: https://doi.org/10.1007/s00213-003-1640-6
substance_tags: psilocybin
topic_tags: Anxiety,Receptor Pharmacology,Consciousness,Emotional Processing
study_type: Other
source_name: Europe PMC
publication_status: published
date_added: 2026-07-01 06:54:14
last_checked: 2026-07-01 11:22:07
title:
Acute psychological and physiological effects of psilocybin in healthy humans: a double-blind, placebo-controlled dose-effect study.

abstract:
RationaleSerotonin (5-Hydroxytryptamine, 5-HT) receptors play an important role in perception, affect regulation and attention. Pharmacological challenge with the 5-HT(2A) agonist psilocybin (PY) is useful in studying the neurobiological basis of cognition and consciousness.ObjectiveInvestigation of dose-dependent effects of PY on psycho(patho)logical and physiological parameters.MethodsEight subjects received placebo (PL), and 45 ("very low dose, VLD"), 115 ("low dose, LD"), 215 ("medium dose, MD"), and 315 ("high dose, HD") microg/kg body weight PY. The "Altered States of Consciousness Rating Scale" (5D-ASC), the "Frankfurt Attention Inventory" (FAIR), and the "Adjective Mood Rating Scale" (AMRS) were used to assess the effects of PY on psycho(patho)logical core dimensions, attention, and mood. A24-h electrocardiogram (EKG) was recorded and blood pressure was measured. Plasma concentrations of thyroid-stimulating hormone (TSH), prolactin (PRL), cortisol (CORT), adrenocorticotropic hormone (ACTH), and standard clinical chemical parameters were determined.ResultsPY dose dependently increased scores of all 5D-ASC core dimensions. Only one subject reacted with transient anxiety to HD PY. Compared with PL, MD and HD PY led to a 50% reduction of performance in the FAIR test. "General inactivation", "emotional excitability", and "dreaminess" were the only domains of the AMRS showing increased scores following MD and HD PY. The mean arterial blood pressure (MAP) was moderately elevated only 60 min following administration of HD PY. Neither EKG nor body temperature was affected by any dose of PY. TSH, ACTH, and CORT plasma levels were elevated during peak effects of HD PY, whereas PRL plasma levels were increased following MD and HD PY.ConclusionPY affects core dimensions of altered states of consciousness and physiological parameters in a dose-dependent manner. Our study provided no cause for concern that PY is hazardous with respect to somatic health.

keywords:
Humans, Analysis of Variance, Double-Blind Method, Affect, Attention, Blood Pressure, Heart Rate, Dose-Response Relationship, Drug, Adult, Female, Male, Psilocybin

raw_json:
{"europe_pmc_id":"14615876","source":"MED","pub_type":null,"publisher":null,"importer":"Europe PMC"}


title: Khat and mushrooms associated with psychosis.
authors: Nielen RJ, van der Heijden FM, Tuinier S, Verhoeven WM.
publication_date: 2003-12-31
doi: 10.1080/15622970410029908
pubmed_id: 15048636
source_url: https://doi.org/10.1080/15622970410029908
keywords: Humans, Agaricales, Catha, Psychomotor Agitation, Psychotic Disorders, Adult, Male
substance_tags: psilocybin
topic_tags: Review Article
study_type: Review Article
source_name: Europe PMC
publication_status: published
date_added: 2026-07-01 06:54:14
last_checked: 2026-07-01 11:22:07
abstract:
ObjectiveThis paper describes two cases with khat- and two with psilocybin-induced psychoses and draws attention to the medical and social consequences of the use of these drugs.MethodTwo male patients are presented who developed relapsing and short-lasting psychotic episodes after chewing kath leaves. In addition, two male patients are reported who showed an acute exacerbation of psychosis after ingestion of psilocybin mushrooms. In addition, a review of the literature is presented.ResultsThe khat-induced psychotic symptoms disappeared without any treatment within one week. One of the patients with a psilocybin-induced psychosis was treated with risperidone. In the other, symptomatology subsided in a few days. No somatic medical complications occurred.ConclusionAdequate psychiatric diagnosis and treatment of the psychoses and the negative social consequences of the use of these drugs are stressed as well as the delineation from functional psychoses in cases of chronic use. The latter applies to patients with psychiatric comorbidity in particular.

raw_json:
{"europe_pmc_id":"15048636","source":"MED","pub_type":null,"publisher":null,"importer":"Europe PMC"}


title: Morphological and chemical analysis of magic mushrooms in Japan.
authors: Tsujikawa K, Kanamori T, Iwata Y, Ohmae Y, Sugita R, Inoue H, Kishi T.
publication_date: 2003-11-30
doi: 10.1016/j.forsciint.2003.08.009
pubmed_id: 14642723
source_url: https://doi.org/10.1016/j.forsciint.2003.08.009
substance_tags: psilocybin,psilocin
topic_tags: General
study_type: Other
source_name: Europe PMC
publication_status: published
date_added: 2026-07-01 06:54:14
last_checked: 2026-07-01 11:22:06
abstract:
Morphological and toxicological analyses were performed on hallucinogenic mushrooms that are currently circulated in Japan. Scanning electron microscope (SEM) indicated a three-dimensional microstructures in the mushrooms. The complementary use of SEM with an optical microscope was effective for observing characteristic tissues, such as basidiomycetes, spores, cystidia and basidia. Hallucinogenic alkaloids were extracted with methanol and determined by high performance liquid chromatography (HPLC) with a UV detector set at 220 nm. The psilocin/psilocybin contents in Psilocybe cubensis were in the range of 0.14-0.42%/0.37-1.30% in the whole mushroom (0.17-0.78%/0.44-1.35% in the cap and 0.09-0.30%/0.05-1.27% in the stem), respectively. The hallucinogenic alkaloids in Copelandia were 0.43-0.76%/0.08-0.22% in the whole mushroom (0.64-0.74%/0.02-0.22% in the cap and 0.31-0.78%/0.01-0.39% in the stem). It thus appears that P. cubensis is psilocybin-rich, whereas Copelandia is psilocin-rich.

keywords:
Agaricales, Spores, Fungal, Plant Stems, Methanol, Alkaloids, Hallucinogens, Solvents, Microscopy, Electron, Scanning, Chromatography, High Pressure Liquid, Forensic Medicine, Japan, Psilocybin

raw_json:
{"europe_pmc_id":"14642723","source":"MED","pub_type":null,"publisher":null,"importer":"Europe PMC"}


title: [Acute higher funghi mushroom poisoning and its treatment].
authors: Saviuc P, Flesch F.
publication_date: 2003-08-31
pubmed_id: 14534493
source_url: https://europepmc.org/article/MED/14534493
keywords: Humans, Mushroom Poisoning, Syndrome, Acute Disease, Time Factors
substance_tags: psilocybin
topic_tags: Mechanism of Action
study_type: Other
source_name: Europe PMC
publication_status: published
date_added: 2026-07-01 06:54:14
last_checked: 2026-07-01 11:22:07
abstract:
PrincipleThe various mushroom poisoning syndromes are summarised together with elements underlining uncertainty and lack of knowledge. For each of the classical syndromes concerned, classified in delays inferior or superior to 6 hours, the toxins and their mechanisms of action, the main mushrooms responsible, the symptoms and their treatment are all presented.Early syndromesCharacterised by early onset within 6 hours, these represent the majority of intoxications. There are 6 syndromes: gastro-intestinal (resinoid), muscarine (sudorien, cholinergic), pantherine (myco-atropine, anticholinergic), coprine (similar to the antabuse syndrome), narcotine (psilocybin, hallucinatory) and paxillus syndrome (exceptional).Late syndromesCharacterised by an onset after six hours, they regroup the phalloid syndrome that is responsible for 90 to 95% of deaths due to higher funghi mushrooms, the orellanine and gyromitrin syndrome and new syndromes identified over the past decade concerning acute renal failure with shorter onset than during the orellanine syndrome (Amanita proxima), erythermalgia (Clitocybe amoenolens), rhabdomyolysis (Tricholoma equestre) and central nervous system failure (Hapalopilus rutilans).

raw_json:
{"europe_pmc_id":"14534493","source":"MED","pub_type":null,"publisher":null,"importer":"Europe PMC"}


title: Psychoactive drugs and quality of life.
authors: Ventegodt S, Merrick J.
publication_date: 2003-08-17
doi: 10.1100/tsw.2003.57
pubmed_id: 12941969
source_url: https://doi.org/10.1100/tsw.2003.57
substance_tags: psilocybin
topic_tags: Addiction,Observational Study,Adolescents
study_type: Observational Study
source_name: Europe PMC
publication_status: published
date_added: 2026-07-01 06:54:14
last_checked: 2026-07-01 11:22:07
abstract:
This study was performed on a representative sample of the Danish population in order to investigate the connection to the use of psychoactive drugs and quality of life (QOL) by way of a questionnaire-based survey. The questionnaire was mailed in February 1993 to 2,460 persons aged between 18 and 88, randomly selected from the CPR (Danish Central Register), and 7,222 persons from the Copenhagen Perinatal Birth Cohort 1959-61. A total of 1,501 persons between the ages 18 and 88 years and 4,626 persons between the ages 31 and 33 years returned the questionnaire (response rates of 61.0% and 64.1%, respectively). Variables investigated in this study were ten different psychotropic drugs and quality of life. Our study showed that over half the Danish population had used illegal psychotropic drugs. The most commonly used was cannabis (marijuana) though experience of this drug appeared not to co-vary with QOL to any significant extent. Cocaine, amphetamine, and psilocybin had been used by 1.2 to 3.3% of the population and this varied with QOL to a clear albeit small extent. LSD has been used by 1.2% of the population and the users had a QOL score 10% lower than those who had never used psychotropic drugs. The group with the lowest quality of life was found to be persons who had used heroin, morphine, methadone, and a mixture of alcohol and tranquilizers (10-20% below the group with the highest quality of life).

keywords:
Humans, Substance-Related Disorders, Marijuana Abuse, Amphetamines, Methadone, Morphine, Heroin, Cocaine, Hallucinogens, Psychotropic Drugs, Data Collection, Cohort Studies, Quality of Life, Adolescent, Adult, Aged, Aged, 80 and over, Middle Aged, Stimulants, Historical, Surveys and Questionnaires

raw_json:
{"europe_pmc_id":"12941969","source":"MED","pub_type":null,"publisher":null,"importer":"Europe PMC"}


title: [Levels of psilocybin and psilocin in various types of mushrooms].
authors: Stríbrný J, Borovicka J, Sokol M.
publication_date: 2003-06-30
pubmed_id: 14631713
source_url: https://europepmc.org/article/MED/14631713
keywords: Agaricales, Hallucinogens, Czech Republic, Gas Chromatography-Mass Spectrometry, Psilocybin
substance_tags: psilocybin,psilocin
topic_tags: General
study_type: Other
source_name: Europe PMC
publication_status: published
date_added: 2026-07-01 06:54:14
last_checked: 2026-07-01 11:22:04
abstract:
Psilocin and psilocybin are psychoactive components of mushrooms of the genus Psilocybe and many others (Panaeolus, Inocybe, Pluteus etc.). In our republic, several species of Psilocybe with a high content of these components can be found. In the present study, we give a semiquantitative content of psilocin and psilocybin in some of our mushrooms in dry substance (Psilocybe semilanceata, Psilocybe bohemica, Psilocybe arcana, Psilocybe cyanescens, Panaeolus acuminatus sensu Ricken, Inocybe haemacta and Pluteus salicinus). For quantification, the GC/MS instrumentation was applied. Psilocin and psilocybin were silylated by the derivatization agent N-methyl-N-trimet-hylsilyltrifluoroacetamide. As an internal standard, 5-methoxytryptamin was used. The results of this study prove the presence of at least three species of Psilocybe with a high content of psychoactive components growing in our republic: Psilocybe semilanceata, Psilocybe bohemica and Psilocybe arcana.

raw_json:
{"europe_pmc_id":"14631713","source":"MED","pub_type":null,"publisher":null,"importer":"Europe PMC"}


title: [Hallucinogens, amphetamines and entactogens].
authors: Vollenweider FX, Vollenweider-Scherpenhuyzen MF.
publication_date: 2003-05-31
doi: 10.1024/0040-5930.60.6.323
pubmed_id: 12848067
source_url: https://doi.org/10.1024/0040-5930.60.6.323
substance_tags: psilocybin
topic_tags: Emotional Processing,Observational Study,Safety,Toxicity
study_type: Observational Study
source_name: Europe PMC
publication_status: published
date_added: 2026-07-01 06:54:14
last_checked: 2026-07-01 11:22:07
abstract:
MDMA ("Ecstasy") and its analogues such as MDE and MDA are amphetamine derivatives reported to produce an altered state with emotional overtones. Since more than ten years, ecstasy is after cannabis the most frequently used recreational drug by young adults, particularly in the so-called techno-scene. However, according to a recent survey there is an increasing trend for a revival of classic amphetamine and hallucinogen abuse, possibly due to the concern about the potential neurotoxicity and somatic risks associated with ecstasy use. Of the hallucinogens consumed, psilocybin containing mushroom ("magic mushrooms"), but also LSD are at the forefront. The present contribution summarizes the psychological and somatic effects of hallucinogens, amphetamines, and entactogens.

keywords:
Humans, Amphetamine-Related Disorders, Amphetamines, Hallucinogens, Cross-Sectional Studies, Structure-Activity Relationship, Switzerland

raw_json:
{"europe_pmc_id":"12848067","source":"MED","pub_type":null,"publisher":null,"importer":"Europe PMC"}


authors: Carod Artal FJ.
publication_date: 2003-04-30
doi: 10.33588/rn.3610.2003019
pubmed_id: 12766871
source_url: https://doi.org/10.33588/rn.3610.2003019
substance_tags: psilocybin
topic_tags: Review Article,Toxicity
study_type: Review Article
source_name: Europe PMC
publication_status: published
date_added: 2026-07-01 06:54:14
last_checked: 2026-07-01 11:22:07
title:
[Neurological syndromes associated with the ingestion of plants and fungi with a toxic component (II). Hallucinogenic fungi and plants, mycotoxins and medicinal herbs].

abstract:
IntroductionA wide range of fungi and medicinal herbs, rich in hallucinogenic substances and widely used for mystic and medicinal purposes, can give rise to neurotoxic symptoms.DevelopmentWe review the toxic syndromes that can arise from the ingestion of hallucinogenic fungi, cacti and plants, together with descriptions of cases of acute poisoning resulting from the use of medicinal herbs and from foodstuffs that are contaminated by mycotoxins. A series of different psychedelic fungi belonging to the Psilocybe, Panaeolus and Stropharia genera contain hallucinogenic alkaloids such as psilocybin. Some of the most notable plants displaying hallucinogenic and sedative properties are Papaver somniferum, Erytroxylum sp. and Cannabis sativa. Infusions of ayahuasca are obtained from the lianas and roots of different plants with psychoactive properties, such as Banisteriopsis caapi and Psychotria viridis, which contain alkaloids derived from tryptamine and from the beta carboline harmala. Peyote, a cactus rich in mescaline, and Claviceps purpurea (a fungus rich in LSD) are strong hallucinogens. We also examine ergotism and mycotoxicosis from Arthrinium sp. Poisoning from mycotoxin containing moulds on sugar cane can give rise to encephalopathy and late dystonia. Some of the more noteworthy medicinal plants for which neurological toxicity has been reported are Hypericum perforatum, kava kava (Piper methysticum), Aconitum sp. and Callilepis laureola.ConclusionsBecause of the increasingly more widespread consumption of herbs and fungi and their potentially neurotoxic effects, in clinical practice there is a need to be aware of the neurological syndromes deriving from their use.

keywords:
Humans, Fungi, Plants, Medicinal, Neurodegenerative Diseases, Dystonia, Hallucinogens, Mycotoxins, Administration, Oral

raw_json:
{"europe_pmc_id":"12766871","source":"MED","pub_type":null,"publisher":null,"importer":"Europe PMC"}


title: The examination of mushroom poisonings at Akita University.
authors: Gonmori K, Yoshioka N
journal: Legal medicine (Tokyo, Japan)
publication_date: 2003-02-28
doi: 10.1016/s1344-6223(02)00127-x
pubmed_id: 12935559
source_url: https://pubmed.ncbi.nlm.nih.gov/12935559/
substance_tags: psilocybin
topic_tags: General
study_type: Other
source_name: PubMed
publication_status: published
date_added: 2026-07-01 06:54:14
last_checked: 2026-07-01 11:20:41
raw_json: {"pubmed_id":"12935559"}
abstract:
In the past 10 years from 1991 to 2000, the number of consultations to the Japan Poison Information Center were 947 concerning mushroom poisonings. However, those from the hospital cases were not analyzed toxicologically. We examined toxicologically 20 cases (35 patients) of mushroom poisonings from 1993 to 2001. Investigation of amanita toxin poisoning was requested in 19 cases. We could detect the amanita toxin, amanitin, and phalloidin, in two cases, which resulted in concluding the cause of death. A fatal case by the magic mushroom poisoning was analyzed in the blood, urine, and mushroom, and we detected the hallucinogenic substances from the body fluids and ingested mushrooms. We report the results of our examinations, and point out the usefulness of the examination of the mushroom itself and biological samples toxicologically for forensic practice.


authors: Maruyama T, Shirota O, Kawahara N, Yokoyama K, Makino Y, Goda Y.
publication_date: 2003-01-31
doi: 10.3358/shokueishi.44.44
pubmed_id: 12749196
source_url: https://doi.org/10.3358/shokueishi.44.44
keywords: Agaricales, DNA, Intergenic, Hallucinogens, Base Sequence, Psilocybin
substance_tags: psilocybin,psilocin
topic_tags: General
study_type: Other
source_name: Europe PMC
publication_status: published
date_added: 2026-07-01 06:54:14
last_checked: 2026-07-01 11:22:06
title:
[Discrimination of psychoactive fungi (commonly called "magic mushrooms") based on the DNA sequence of the internal transcribed spacer region].

abstract:
'Magic mushrooms' (MMs) are psychoactive fungi containing the hallucinogenic compounds, psilocin (1) and psilocybin (2). Since June 6, 2002, these fungi have been regulated by the Narcotics and Psychotropics Control Law in Japan. Because there are many kinds of MMs and they are sold even as dry powders in local markets, it is very difficult to identify the original species of the MMs by morphological observation. Therefore, we investigated the internal transcribed spacer (ITS) region in the ribosomal RNA gene of MMs obtained in Japanese markets to classify them by a genetic approach. Based on the size and nucleotide sequence of the ITS region amplified by PCR, tested MMs were classified into 6 groups. Furthermore, a comparison of the DNA sequences of the MMs with those of authentic samples or with those found in the databases (GenBank, EMBL and DDBJ) made it possible to identify the species of tested MMs. Analysis by LC revealed that psilocin (1) was contained at the highest level in Panaeolus cyanescens among the MMs, but was absent in the Amanita species.

raw_json:
{"europe_pmc_id":"12749196","source":"MED","pub_type":null,"publisher":null,"importer":"Europe PMC"}


authors: Umbricht D, Vollenweider FX, Schmid L, Grübel C, Skrabo A, Huber T, Koller R.
publication_date: 2002-12-31
doi: 10.1038/sj.npp.1300005
pubmed_id: 12496954
source_url: https://doi.org/10.1038/sj.npp.1300005
substance_tags: psilocybin
topic_tags: Pharmacology,Receptor Pharmacology,Healthy Volunteers
study_type: Other
source_name: Europe PMC
publication_status: published
date_added: 2026-07-01 06:54:14
last_checked: 2026-07-01 11:22:06
title:
Effects of the 5-HT2A agonist psilocybin on mismatch negativity generation and AX-continuous performance task: implications for the neuropharmacology of cognitive deficits in schizophrenia.

abstract:
Previously the NMDA (N-methyl-D-aspartate) receptor (NMDAR) antagonist ketamine was shown to disrupt generation of the auditory event-related potential (ERP) mismatch negativity (MMN) and the performance of an 'AX'-type continuous performance test (AX-CPT)--measures of auditory and visual context-dependent information processing--in a similar manner as observed in schizophrenia. This placebo-controlled study investigated effects of the 5-HT(2A) receptor agonist psilocybin on the same measures in 18 healthy volunteers. Psilocybin administration induced significant performance deficits in the AX-CPT, but failed to reduce MMN generation significantly. These results indirectly support evidence that deficient MMN generation in schizophrenia may be a relatively distinct manifestation of deficient NMDAR functioning. In contrast, secondary pharmacological effects shared by NMDAR antagonists and the 5-HT(2A) agonist (ie disruption of glutamatergic neurotransmission) may be the mechanism underlying impairments in AX-CPT performance observed during both psilocybin and ketamine administration. Comparable deficits in schizophrenia may result from independent dysfunctions of 5-HT(2A) and NMDAR-related neurotransmission.

keywords:
Humans, Receptors, Serotonin, Receptor, Serotonin, 5-HT2A, Receptors, N-Methyl-D-Aspartate, Electroencephalography, Orientation, Psychomotor Performance, Cognition Disorders, Schizophrenic Psychology, Evoked Potentials, Evoked Potentials, Auditory, Adult, Female, Male, Serotonin Receptor Agonists, Psilocybin, Discrimination, Psychological

raw_json:
{"europe_pmc_id":"12496954","source":"MED","pub_type":null,"publisher":null,"importer":"Europe PMC"}


authors: Riba J, Rodríguez-Fornells A, Barbanoj MJ.
publication_date: 2002-10-11
doi: 10.1007/s00213-002-1237-5
pubmed_id: 12474114
source_url: https://doi.org/10.1007/s00213-002-1237-5
substance_tags: psilocybin
topic_tags: Mechanism of Action,Receptor Pharmacology,Clinical Trial,Observational Study,Healthy Volunteers
study_type: Clinical Trial
source_name: Europe PMC
publication_status: published
date_added: 2026-07-01 06:54:14
last_checked: 2026-07-01 11:22:07
title:
Effects of ayahuasca on sensory and sensorimotor gating in humans as measured by P50 suppression and prepulse inhibition of the startle reflex, respectively.

abstract:
RationaleAyahuasca, a South American psychotropic plant tea, combines the psychedelic agent and 5-HT(2A/2C) agonist N, N-dimethyltryptamine (DMT) with beta-carboline alkaloids showing monoamine oxidase-inhibiting properties. Current human research with psychedelics and entactogens has explored the possibility that drugs displaying agonist activity at the 5-HT(2A/2C) sites temporally disrupt inhibitory neural mechanisms thought to intervene in the normal filtering of information. Suppression of the P50 auditory evoked potential (AEP) and prepulse inhibition of startle (PPI) are considered operational measures of sensory (P50 suppression) and sensorimotor (PPI) gating. Contrary to findings in lower animals, unexpected increases in sensorimotor gating have been found in humans following the administration of the serotonergic psychedelic psilocybin and the serotonin releaser 3,4-methylenedioxymethamphetamine (MDMA). In addition, to our knowledge P50 suppression has not been assessed previously in humans following the administration of a 5-HT(2A/2C) agonist.ObjectivesTo assess the effects of the acute administration of ayahuasca on P50 suppression and PPI in humans, in order to evaluate the drug's modulatory actions on these measures of sensory and sensorimotor gating.MethodsEighteen healthy volunteers with prior experience of psychedelic drug use participated in a clinical trial in which placebo or ayahuasca doses (0.6 mg and 0.85 mg DMT/kg body weight) were administered according to a double-blind, cross-over balanced design. P50 and startle reflex (pulse-alone and 60 ms, 120 ms, 240 ms and 2000 ms prepulse-to-pulse intervals) recordings were undertaken at 1.5 h and 2 h after drug intake, respectively.ResultsAyahuasca produced diverging effects on each of the two gating measures evaluated. Whereas significant dose-dependent reductions of P50 suppression were observed after ayahuasca, no significant effects were found on the startle response, its habituation rate, or on PPI at any of the prepulse-to-pulse intervals studied.ConclusionThe present findings indicate, at the doses tested, a decremental effect of ayahuasca on sensory gating, as measured by P50 suppression, and no distinct effects on sensorimotor gating, as measured by PPI.

keywords:
Humans, Banisteriopsis, Plants, Medicinal, Psychotropic Drugs, Plant Extracts, Acoustic Stimulation, Analysis of Variance, Double-Blind Method, Sensory Thresholds, Psychomotor Performance, Evoked Potentials, Auditory, Neural Inhibition, Dose-Response Relationship, Drug, Adult, Female, Male, Habituation, Psychophysiologic, Reflex, Startle, Surveys and Questionnaires

raw_json:
{"europe_pmc_id":"12474114","source":"MED","pub_type":null,"publisher":null,"importer":"Europe PMC"}


title: Psychotropic drugs in developmental mushrooms: a case study review.
authors: Gross ST.
publication_date: 2002-10-31
doi: 10.1520/jfs15564j
pubmed_id: 12455653
source_url: https://doi.org/10.1520/jfs15564j
substance_tags: psilocybin
topic_tags: Review Article
study_type: Review Article
source_name: Europe PMC
publication_status: published
date_added: 2026-07-01 06:54:14
last_checked: 2026-07-01 11:22:07
abstract:
Psilocyn and psilocybin can be identified in different stages of developing psilocybe mushrooms. Knowing the various stages of the mushroom development can be useful when receiving evidence from illicit mushroom growing operations. Exhibits from three separate cases were submitted to the drug analysis section of the Minnesota Bureau of Criminal Apprehension Forensic Science Laboratory. Each case contained different stages of developing mushrooms. This report describes the evidence in each case, the sample preparation, the sample analysis and the final report that was written.

keywords:
Agaricales, Psychotropic Drugs, Chromatography, Thin Layer, Forensic Medicine, Molecular Structure, Gas Chromatography-Mass Spectrometry, Psilocybin, Illicit Drugs

raw_json:
{"europe_pmc_id":"12455653","source":"MED","pub_type":null,"publisher":null,"importer":"Europe PMC"}


title: The pharmacology of psilocybin.
authors: Passie T, Seifert J, Schneider U, Emrich HM.
publication_date: 2002-09-30
doi: 10.1080/1355621021000005937
pubmed_id: 14578010
source_url: https://doi.org/10.1080/1355621021000005937
substance_tags: psilocybin
topic_tags: Neuroplasticity,Pharmacology,Receptor Pharmacology,Clinical Trial,Review Article,Animal Study
study_type: Clinical Trial
source_name: Europe PMC
publication_status: published
date_added: 2026-07-01 06:54:14
last_checked: 2026-07-01 11:22:06
abstract:
Psilocybin (4-phosphoryloxy-N,N-dimethyltryptamine) is the major psychoactive alkaloid of some species of mushrooms distributed worldwide. These mushrooms represent a growing problem regarding hallucinogenic drug abuse. Despite its experimental medical use in the 1960s, only very few pharmacological data about psilocybin were known until recently. Because of its still growing capacity for abuse and the widely dispersed data this review presents all the available pharmacological data about psilocybin.

keywords:
Brain, Animals, Humans, Mice, Agaricales, Substance-Related Disorders, Serotonin, Receptors, Presynaptic, Hallucinogens, Somatoform Disorders, Controlled Clinical Trials as Topic, Psilocybin

raw_json:
{"europe_pmc_id":"14578010","source":"MED","pub_type":null,"publisher":null,"importer":"Europe PMC"}


authors: Hasler F, Bourquin D, Brenneisen R, Vollenweider FX.
publication_date: 2002-08-31
doi: 10.1016/s0731-7085(02)00278-9
pubmed_id: 12191719
source_url: https://doi.org/10.1016/s0731-7085(02)00278-9
substance_tags: psilocybin,psilocin
topic_tags: General
study_type: Other
source_name: Europe PMC
publication_status: published
date_added: 2026-07-01 06:54:14
last_checked: 2026-07-01 11:22:05
title:
Renal excretion profiles of psilocin following oral administration of psilocybin: a controlled study in man.

abstract:
In a clinical study eight volunteers received psilocybin (PY) in psychoactive oral doses of 212+/-25 microg/kg body weight. To investigate the elimination kinetics of psilocin (PI), the first metabolite of PY, urine was collected for 24 h and PI concentrations were determined by high-performance liquid chromatography with column switching and electrochemical detection (HPLC-ECD). Sample workup included protection of the unstable PI with ascorbic acid, freeze-drying, and extraction with methanol. Peak PI concentrations up to 870 microg/l were measured in urine samples from the 2-4 h collection interval. The PI excretion rate in this period was 55.5+/-33.8 microg/h. The limit of quantitation (10 microg/L) was usually reached 24 h after drug administration. Within 24 h, 3.4+/-0.9% of the applied dose of PY was excreted as free PI. Addition of beta-glucuronidase to urine samples and incubation for 5 h at 40 degrees C led to twofold higher PI concentrations, although 18+/-7% of the amount of unconjugated PI was decomposed during incubation. We conclude that in humans PI is partially excreted as PI-O-glucuronide and that enzymatic hydrolysis extends the time of detectability for PI in urine samples.

keywords:
Humans, Chromatography, High Pressure Liquid, Administration, Oral, Affect, Adult, Middle Aged, Female, Male, Psilocybin

raw_json:
{"europe_pmc_id":"12191719","source":"MED","pub_type":null,"publisher":null,"importer":"Europe PMC"}


title: Ecstasy and drug consumption patterns: a Canadian rave population study.
authors: Gross SR, Barrett SP, Shestowsky JS, Pihl RO.
publication_date: 2002-07-31
doi: 10.1177/070674370204700606
pubmed_id: 12211882
source_url: https://doi.org/10.1177/070674370204700606
substance_tags: psilocybin
topic_tags: Addiction,Observational Study
study_type: Observational Study
source_name: Europe PMC
publication_status: published
date_added: 2026-07-01 06:54:14
last_checked: 2026-07-01 11:22:07
abstract:
ObjectiveThis study investigates the drug consumption patterns of a sample of rave attendees in the city of Montreal, Quebec, and seeks to identify the prevalence of 3,4-methylendioxymethamphetamine (MDMA) and other drug use in this population.MethodWe administered a self-report questionnaire to 210 respondents. For various licit and illicit substances, participants reported their age of first use, number of lifetime uses, and usage in the previous 30 days.ResultsWe found a significant rank order for the sequence of first use: 1) alcohol, 2) nicotine, 3) cannabis, 4) LSD, 5) psilocybin, 6) amphetamine, 7) cocaine, 8) MDMA, 9) gamma-hydroxybutyrate (GHB), 10) ephedrine, 11) ketamine. Alcohol and cannabis were the most commonly used substances, both in cumulative number of lifetime uses and in usage in the preceding 30 days. MDMA and amphetamine were also notable as the next 2 most popular drugs for use in the preceding 30 days and in terms of those who had tried the drugs at least once. We identified a progressive rank order of experimentation, with early alcohol or cannabis use (or both) associated with the early use of all other drugs tried by more than 25% of the sample. We found MDMA and amphetamine use to be prevalent, as was general experimentation with all drugs studied, other than heroin.ConclusionDrug consumption levels were substantial in this "rave" population, particularly with respect to recent use of MDMA, amphetamine, cannabis, and alcohol. Results also indicate that the sequence of drug experimentation in this population follows an identifiable pattern.

keywords:
Humans, Substance-Related Disorders, N-Methyl-3,4-methylenedioxyamphetamine, Hallucinogens, Self Administration, Drug Administration Schedule, Incidence, Prevalence, Retrospective Studies, Preventive Health Services, Canada, Surveys and Questionnaires

raw_json:
{"europe_pmc_id":"12211882","source":"MED","pub_type":null,"publisher":null,"importer":"Europe PMC"}


authors: ten Berge J.
publication_date: 2002-06-30
doi: 10.1080/02791072.2002.10399961
pubmed_id: 12422935
source_url: https://doi.org/10.1080/02791072.2002.10399961
substance_tags: psilocybin
topic_tags: Creativity
study_type: Other
source_name: Europe PMC
publication_status: published
date_added: 2026-07-01 06:54:14
last_checked: 2026-07-01 11:22:07
title:
Jekyll and Hyde revisited: paradoxes in the appreciation of drug experiences and their effects on creativity.

abstract:
Historically, states of intoxication--like dreams and madness--are seen in either one of two opposed ways. The intoxicated are either "possessed" or "under the influence" of an external agency, or revealing hidden feelings or truths (in vino veritas). Along the same lines, artists who worked during LSD, mescalin or psilocybin intoxication often refer to feelings of either being "possessed" or "liberated," a difference that can be explained partly by their expectations and partly by their evaluations, which both tend to conform to the cultural dichotomy in interpreting the irrational. Both interpretations, however, tend to obscure not only the other, but also-it is posited-the paradoxical nature of the drug experience itself. Analysis of a protocol shows that intoxication might comprise feelings of "possession" as well as "liberation" almost simultaneously, and mediumistic and some psychedelic art shows stylistic traits that can be seen as the visual expressions of both these feelings. It seems that the "demoniacal" and "psychedelic" mode come together in experiential reality, only to be divided in the cultural sphere.

keywords:
Humans, Mescaline, Lysergic Acid Diethylamide, Hallucinogens, Internal-External Control, Psychoanalytic Interpretation, Art, History, 20th Century, Mind-Body Relations, Metaphysical, Creativity, Psilocybin

raw_json:
{"europe_pmc_id":"12422935","source":"MED","pub_type":null,"publisher":null,"importer":"Europe PMC"}


title: 5-HT2A receptor-stimulated phosphoinositide hydrolysis in the stimulus effects of hallucinogens.
authors: Rabin RA, Regina M, Doat M, Winter JC.
publication_date: 2002-04-30
doi: 10.1016/s0091-3057(01)00720-1
pubmed_id: 11900766
source_url: https://doi.org/10.1016/s0091-3057(01)00720-1
substance_tags: psilocybin
topic_tags: Mechanism of Action,Receptor Pharmacology,Animal Study
study_type: Animal Study
source_name: Europe PMC
publication_status: published
date_added: 2026-07-01 06:54:14
last_checked: 2026-07-01 11:22:07
abstract:
The role of 5-HT2A-mediated stimulation of phosphoinositide hydrolysis in the discriminative effects of hallucinogens was investigated in PC12 cells stably expressing the rat 5-HT2A receptor (PC12-5-HT2A cells). The hallucinogenic compounds, D-lysergic acid diethylamide (LSD), (-)2,5-dimethoxy-4-methylamphetamine (DOM), psilocybin, N,N-dimethyltryptamine (DMT), 5-methoxy-N,N-dimethyltryptamine (MDMT) and N,N-diethyltryptamine (DET), all caused a concentration-dependent increase in the generation of [3H]inositol phosphates. The nonhallucinogenic compounds, 6-fluoro-N,N-diethyltryptamine (6-F-DET), lisuride and quipazine, also displayed significant efficacy in stimulating phosphoinositide hydrolysis, while 2-bromo-lysergic acid diethylamide (BOL), which is not a hallucinogen, did not alter inositol phosphate generation. The beta-carbolines, harmaline and harmane, also did not alter phosphoinositide hydrolysis. Comparison of these results with previous drug discrimination studies indicated the apparent lack of correlation between the degree of substitution in LSD- and DOM-trained animals and efficacy in stimulating phosphoinositide hydrolysis. The present study indicates that 5-HT2A-mediated stimulation of phosphoinositide hydrolysis does not appear to be the sole critical signaling mechanism involved in the discriminative effects of hallucinogens.

keywords:
PC12 Cells, Animals, Rats, Phosphatidylinositols, Receptors, Serotonin, Receptor, Serotonin, 5-HT2A, Hallucinogens, Hydrolysis, Dose-Response Relationship, Drug

raw_json:
{"europe_pmc_id":"11900766","source":"MED","pub_type":null,"publisher":null,"importer":"Europe PMC"}


title: Drugs of abuse monitoring in blood for control of driving under the influence of drugs.
authors: Moeller MR, Kraemer T.
publication_date: 2002-03-31
doi: 10.1097/00007691-200204000-00003
pubmed_id: 11897967
source_url: https://doi.org/10.1097/00007691-200204000-00003
substance_tags: psilocybin,psilocin
topic_tags: Addiction,Review Article,Safety,Toxicity
study_type: Review Article
source_name: Europe PMC
publication_status: published
date_added: 2026-07-01 06:54:14
last_checked: 2026-07-01 11:22:07
abstract:
Driving under the influence of drugs is an issue of growing concern in the industrialized countries as a risk and a cause for road accidents. In forensic toxicology, the increasing number of samples for determination of drugs in blood is mainly due to zero-tolerance laws in several countries and well-trained police officers who can better recognize drivers under the influence of drugs of abuse. This review describes procedures for detection of the following drugs of abuse in whole blood, plasma, and serum: amphetamine, methamphetamine, 3,4-methylenedioxy methamphetamine (MDMA), N-ethyl-3, 4-methylenedioxyamphetamine (MDEA), 3,4-methylenedioxyamphetamine (MDA), cannabinoids (delta-9-tetrahydrocannabinol [THC], 11-hydroxy-delta-9-THC, 11-nor-9-carboxy-delta-9-THC), cocaine, benzoylecgonine, ecgonine methyl ester, cocaethylene, the opiates (heroin, 6-monoacetylmorphine, morphine, or codeine), and methadone as well as gamma-hydroxybutyric acid (GHB), lysergic acid diethylamide (LSD), phencyclidine (PCP), and psilocybin/psilocin. For many of the analytes, sensitive immunologic methods for screening are available. Gas chromatography-mass spectrometry (GC-MS) is still the state-of-the-art method for confirmatory analysis or for screening and confirmation in one step. Liquid chromatography-mass spectrometry (LC-MS) procedures for such purposes are also included in this review. Basic data about the biosample assayed, internal standard, workup, GC or LC column and mobile phase, detection mode, reference data, and validation data of each procedure are summarized in two tables.

keywords:
Humans, Chromatography, Liquid, Substance Abuse Detection, Forensic Medicine, Accidents, Traffic, Gas Chromatography-Mass Spectrometry, Illicit Drugs

raw_json:
{"europe_pmc_id":"11897967","source":"MED","pub_type":null,"publisher":null,"importer":"Europe PMC"}


authors: Umbricht D, Koller R, Vollenweider FX, Schmid L.
publication_date: 2002-02-28
doi: 10.1016/s0006-3223(01)01242-2
pubmed_id: 11904134
source_url: https://doi.org/10.1016/s0006-3223(01)01242-2
substance_tags: psilocybin
topic_tags: Receptor Pharmacology,Consciousness,Healthy Volunteers
study_type: Other
source_name: Europe PMC
publication_status: published
date_added: 2026-07-01 06:54:14
last_checked: 2026-07-01 11:22:07
title:
Mismatch negativity predicts psychotic experiences induced by NMDA receptor antagonist in healthy volunteers.

abstract:
BackgroundPrevious studies indicate that mismatch negativity (MMN)-a preattentive auditory event-related potential (ERP)-depends on NMDA receptor (NMDAR) functioning. To explore if the strength of MMN generation reflects the functional condition of the NMDAR system in healthy volunteers, we analyzed correlations between MMN recorded before drug administration and subsequent responses to the NMDAR antagonist ketamine or the 5-HT2a agonist psilocybin.MethodsIn two separate studies, MMN was recorded to both frequency and duration deviants prior to administration of ketamine or psilocybin. Behavioral and subjective effects of ketamine and psilocybin were assessed with the Brief Psychiatric Rating Scale and the OAV Scale-a rating scale developed to measure altered states of consciousness. Correlations between ERP amplitudes (MMN, N1, and P2) and drug-induced effects were calculated in each study group and compared between them.ResultsSmaller MMN to both pitch and duration deviants was significantly correlated to stronger effects during ketamine, but not psilocybin administration. No significant correlations were observed for N1 and P2.ConclusionsSmaller MMN indicates a NMDAR system that is more vulnerable to disruption by the NMDAR antagonist ketamine. MMN generation appears to index the functional state of NMDAR-mediated neurotransmission even in subjects who do not demonstrate any psychopathology.

keywords:
Cerebral Cortex, Humans, Psychoses, Substance-Induced, Ketamine, Receptors, Serotonin, Receptor, Serotonin, 5-HT2A, Receptors, N-Methyl-D-Aspartate, Electroencephalography, Administration, Oral, Infusions, Intravenous, Psychiatric Status Rating Scales, Contingent Negative Variation, Evoked Potentials, Auditory, Adult, Female, Male, Psilocybin

raw_json:
{"europe_pmc_id":"11904134","source":"MED","pub_type":null,"publisher":null,"importer":"Europe PMC"}


title: What geometric visual hallucinations tell us about the visual cortex.
authors: Bressloff PC, Cowan JD, Golubitsky M, Thomas PJ, Wiener MC.
publication_date: 2002-02-28
doi: 10.1162/089976602317250861
pubmed_id: 11860679
source_url: https://doi.org/10.1162/089976602317250861
keywords: Visual Cortex, Humans, Hallucinations, Mathematics, Models, Neurological
substance_tags: psilocybin
topic_tags: Mechanism of Action
study_type: Other
source_name: Europe PMC
publication_status: published
date_added: 2026-07-01 06:54:14
last_checked: 2026-07-01 11:22:07
abstract:
Many observers see geometric visual hallucinations after taking hallucinogens such as LSD, cannabis, mescaline or psilocybin; on viewing bright flickering lights; on waking up or falling asleep; in "near-death" experiences; and in many other syndromes. Klüver organized the images into four groups called form constants: (I) tunnels and funnels, (II) spirals, (III) lattices, including honeycombs and triangles, and (IV) cobwebs. In most cases, the images are seen in both eyes and move with them. We interpret this to mean that they are generated in the brain. Here, we summarize a theory of their origin in visual cortex (area V1), based on the assumption that the form of the retino-cortical map and the architecture of V1 determine their geometry. (A much longer and more detailed mathematical version has been published in Philosophical Transactions of the Royal Society B, 356 [2001].) We model V1 as the continuum limit of a lattice of interconnected hypercolumns, each comprising a number of interconnected iso-orientation columns. Based on anatomical evidence, we assume that the lateral connectivity between hypercolumns exhibits symmetries, rendering it invariant under the action of the Euclidean group E(2), composed of reflections and translations in the plane, and a (novel) shift-twist action. Using this symmetry, we show that the various patterns of activity that spontaneously emerge when V1's spatially uniform resting state becomes unstable correspond to the form constants when transformed to the visual field using the retino-cortical map. The results are sensitive to the detailed specification of the lateral connectivity and suggest that the cortical mechanisms that generate geometric visual hallucinations are closely related to those used to process edges, contours, surfaces, and textures.

raw_json:
{"europe_pmc_id":"11860679","source":"MED","pub_type":null,"publisher":null,"importer":"Europe PMC"}


title: Possible mechanisms of panic attack and schizophrenia via APUD system.
authors: Fukuda K.
publication_date: 2002-01-31
doi: 10.1054/mehy.2001.1473
pubmed_id: 11812187
source_url: https://doi.org/10.1054/mehy.2001.1473
substance_tags: psilocybin
topic_tags: Mechanism of Action,Receptor Pharmacology,Biomarkers
study_type: Clinical Trial
source_name: Europe PMC
publication_status: published
date_added: 2026-07-01 06:54:14
last_checked: 2026-07-01 11:22:07
abstract:
Psilocybin poisoning produces biphasic reactions composed of a schizophrenic phase and a panic attack-like phase. There is a time lag of several hours between phases, which may be considered an accumulation time in certain sites between the gut and the brain. So far as 5-hydroxytryptamine (5-HT) congeners are concerned, no sites are to be found except the amine precursor uptake and decarboxylation (APUD) system. It is postulated that argyrophil cells (AC) in the foregut, neuroepithelial bodies (NEB) in the lung, and raphe nuclei (RN) in the brainstem axis are relevant to mental disorders. Schizophrenia might be due to the massive destruction of APUD cells, and the paroxysmal release of 5-HT with peptides and panneuroendocrine markers from NEB might be the cause of panic attack.

keywords:
Raphe Nuclei, APUD Cells, Humans, Serotonin, Hallucinogens, Panic Disorder, Schizophrenia, Models, Biological, Psilocybin

raw_json:
{"europe_pmc_id":"11812187","source":"MED","pub_type":null,"publisher":null,"importer":"Europe PMC"}


title: Effects of the hallucinogen psilocybin on covert orienting of visual attention in humans.
authors: Gouzoulis-Mayfrank E, Thelen B, Maier S, Heekeren K, Kovar KA, Sass H, Spitzer M.
publication_date: 2001-12-31
doi: 10.1159/000063672
pubmed_id: 12097810
source_url: https://doi.org/10.1159/000063672
substance_tags: psilocybin
topic_tags: Healthy Volunteers
study_type: Other
source_name: Europe PMC
publication_status: published
date_added: 2026-07-01 06:54:14
last_checked: 2026-07-01 11:22:06
abstract:
Hallucinogenic drug-induced states are considered as models for acute schizophrenic disorders (experimental psychoses). In a double-blind study with healthy volunteers we investigated the influence of the serotonergic hallucinogen psilocybin, the ecstasy-like drug 3,4-methylenedioxyethylamphetamine (MDE), the stimulant d- methamphetamine and placebo on covert orienting of spatial attention (n = 8 in each group). Reaction times were prolonged after ingestion of psilocybin > MDE, but not after d-methamphetamine. In addition, subjects on psilocybin exhibited particularly slow reaction times in invalid trials at short cue target intervals and failure of response inhibition in valid trials at long cue target intervals for right visual field targets. Despite some methodological limitations, these results are in line with both bilateral impairment of disengagement of attention and a lateralized impairment of inhibition of return (IOR) in productive psychotic states. Additional investigations with larger samples, different hallucinogenic substances (serotonergic agonists vs. NMDA antagonists) and different dose regimens are needed in order to further explore the suggested relationship between visuospatial attentional dysfunction and acute psychotic conditions.

keywords:
Humans, Methamphetamine, 3,4-Methylenedioxyamphetamine, Central Nervous System Stimulants, Hallucinogens, Double-Blind Method, Space Perception, Visual Perception, Attention, Reaction Time, Adult, Middle Aged, Female, Male, Psilocybin

raw_json:
{"europe_pmc_id":"12097810","source":"MED","pub_type":null,"publisher":null,"importer":"Europe PMC"}


title: Brain mechanisms of hallucinogens and entactogens.
authors: Vollenweider FX.
publication_date: 2001-11-30
doi: 10.31887/dcns.2001.3.4/fxvollenweider
pubmed_id: 22033605
source_url: https://doi.org/10.31887/dcns.2001.3.4/fxvollenweider
substance_tags: psilocybin
topic_tags: Brain Imaging,Mechanism of Action,Receptor Pharmacology,Aging,Emotional Processing,Review Article
study_type: Review Article
source_name: Europe PMC
publication_status: published
date_added: 2026-07-01 06:54:14
last_checked: 2026-07-01 11:22:07
abstract:
This review focuses on recent brain imaging and behavioral studies of sensory gating functions, which assess similarities between the effects of classic hallucinogens (eg, psilocybin), dissociative anesthetics (eg, ketamine), and entactogens (eg, 3,4-methylenedioxymethamphetamine [MDMA]) in humans. Serotonergic hallucinogens and psychotomimetic anesthetics produce overlapping psychotic syndromes associated with a marked activation of the prefrontal cortex (hyperfrontality) and other overlapping changes in temporoparietal, striatal, and thalamic regions, suggesting that both classes of drugs act upon a common final pathway. Together with the observation that both hallucinogens and N-methyl-oaspartate (NMDA) antagonists disrupt sensory gating in rats by acting on 5-hydroxytryptamine (serotonin) 5-HT(2) receptors located in cortico-striato-thalamic circuitry these findings suggest that disruption of cortico-subcortical processing leading to sensory overload of the cortex is a communality of these psychoses. In contrast to hallucinogens, the entactogen MDMA produces an emotional state of positive mood, concomitant with an activation of prefrontolimbiclparalimbic structures and a deactivation of amygdala and thalamus.

raw_json:
{"europe_pmc_id":"22033605","source":"MED","pub_type":null,"publisher":null,"importer":"Europe PMC"}


title: A systems model of altered consciousness: integrating natural and drug-induced psychoses.
authors: Vollenweider FX, Geyer MA.
publication_date: 2001-10-31
doi: 10.1016/s0361-9230(01)00646-3
pubmed_id: 11750795
source_url: https://doi.org/10.1016/s0361-9230(01)00646-3
substance_tags: psilocybin
topic_tags: Brain Imaging,Mechanism of Action,Receptor Pharmacology,Consciousness,Aging
study_type: Other
source_name: Europe PMC
publication_status: published
date_added: 2026-07-01 06:54:14
last_checked: 2026-07-01 11:22:07
abstract:
Increasing evidence from neuroimaging and behavioral studies suggests that functional disturbances within cortico-striato-thalamic pathways are critical to psychotic symptom formation in drug-induced and possibly also naturally occurring psychoses. Recent basic and clinical research with psychotomimetic drugs, such as the N-methyl-D-aspartate (NMDA) glutamate receptor antagonist, ketamine, and the serotonin-2A (5-HT(2A)) receptor agonist, psilocybin, suggest that the hallucinogenic effects of these drugs arise, at least in part, from their common capacity to disrupt thalamo-cortical gating of external and internal information to the cortex. Deficient gating of sensory and cognitive information is thought to result in an overloading inundation of information and subsequent cognitive fragmentation and psychosis. Cross-species studies of homologues gating functions, such as prepulse inhibition of the startle reflex, in animal and human models of psychosis corroborate this view and provide a translational testing mechanism for the exploration of novel pathophysiologic and therapeutic hypotheses relevant to psychotic disorders, such as the group of schizophrenias.

keywords:
Brain, Neural Pathways, Animals, Humans, Consciousness Disorders, Psychoses, Substance-Induced, Receptors, N-Methyl-D-Aspartate, Hallucinogens, Schizophrenia, Models, Neurological

raw_json:
{"europe_pmc_id":"11750795","source":"MED","pub_type":null,"publisher":null,"importer":"Europe PMC"}


title: Characteristics of pregnant women who use ecstasy (3, 4-methylenedioxymethamphetamine).
authors: Ho E, Karimi-Tabesh L, Koren G
journal: Neurotoxicology and teratology
publication_date: 2000-12-31
doi: 10.1016/s0892-0362(01)00178-7
pubmed_id: 11792525
source_url: https://pubmed.ncbi.nlm.nih.gov/11792525/
substance_tags: psilocybin
topic_tags: Addiction,Emotional Processing,Observational Study,Safety
study_type: Observational Study
source_name: PubMed
publication_status: published
date_added: 2026-07-01 06:54:14
last_checked: 2026-07-01 06:54:14
raw_json: {"pubmed_id":"11792525"}
abstract:
To determine the characteristics of pregnant women who use Ecstasy (3,4-methylenedioxymethamphetamine, MDMA), and to identify reproductive risk factors associated with this group of women. Prospective, observational study. Pregnant women who have contacted the Motherisk Alcohol and Substance Use Helpline at The Hospital for Sick Children, in Toronto, about exposure to drugs, chemicals, infection or radiation. All inquiries from December 1998 to October 2000 concerning pregnant women who reported use of MDMA, and control cases of women not exposed to MDMA selected within the same week of the MDMA callers. Age, maternal demographics, pregnancy characteristics, patterns of alcohol, tobacco, and illicit drug use, psychological/emotional status, sexually transmitted disease, MDMA method and pattern of use, and adverse drug reactions after ingestion of MDMA. The 132 pregnant women who used MDMA were significantly younger (mean 23.2 vs. 31.2 years, P<.0001), and had more unplanned pregnancies compared to 122 pregnant nonusers (84.2% vs. 54.3%, P<.05). MDMA users were also more likely to be single (57.0% vs. 18.3%, P<.001), and to be White (82.2% vs. 56.0%, P<.05). Comparably more MDMA users smoked cigarettes (53.8% vs. 19.7%, P<.0001), drank alcohol (66.4% vs. 37.3%, P<.0001), and had significantly more episodes of binge drinking during pregnancy (mean 2.12 vs. 0.05, P<.001). Illicit drugs such as cocaine, marijuana, methamphetamine, ketamine, gamma-hydroxy butyrate, and psilocybin were used more frequently among the MDMA sample. Over a third of MDMA users reported psychiatric/emotional problems, including 6.5% with a clinically diagnosed condition that was being treated with medication and/or counseling. Pregnant women who use MDMA tend to be young, single, and report psychological morbidity, and have a clustering of risk factors that may compromise the pregnancy and fetus. Smoking, heavy alcohol intake, and polydrug use, combined with a higher than expected rate of unplanned pregnancies, increases the risk of fetal exposure to potentially harmful substances. It is important to account for the range of confounding risk factors among women who use MDMA in order to define possible direct effects of MDMA in pregnancy.


title: Patterns of recreational drug use at dance events in Edinburgh, Scotland.
authors: Riley SC, James C, Gregory D, Dingle H, Cadger M.
publication_date: 2001-06-30
doi: 10.1046/j.1360-0443.2001.967103513.x
pubmed_id: 11440614
source_url: https://doi.org/10.1046/j.1360-0443.2001.967103513.x
substance_tags: psilocybin
topic_tags: Addiction,Observational Study,Adolescents,Safety
study_type: Observational Study
source_name: Europe PMC
publication_status: published
date_added: 2026-07-01 06:54:14
last_checked: 2026-07-01 11:22:07
abstract:
AimsTo describe the patterns of drug use at dance (rave) events in terms of prevalence, frequency, type of drugs used, patterns of use, access and risk-associated behaviours.DesignSelf-selecting participant-completed survey.SettingThree dance events in Edinburgh, Scotland, UK.ParticipantsOne hundred and twenty-two drug users (57% males, 43% females), 90% of whom were in employment or education, with an age range of 16-47, 80% between 18 and 23 years.MeasurementsParticipants who answered 'yes' to the question 'Have you used drugs for dance events in the past year' reported (i) the prevalence, types and frequency of drugs used; (ii) prevalence and contents of mixing drugs; (iii) accessing drugs; and (iv) engagement with drug-associated risk behaviours.FindingsOver 80% of the participants had used ecstasy and amphetamine, over 30% cocaine and LSD; over 10% nitrites, psilocybin and ketamine and less than 5% had used crack or tranquillizers. Participants reported regular consumption of ecstasy and amphetamine (e.g. 35% used ecstasy and 25% amphetamine on a weekly basis) often taken in combination, with the occasional use of cocaine, LSD, ketamine and psilocybin. Poly- and mixing-drug behaviours were significantly more likely than monodrug usage. Drugs were accessed through friends than from any other source. Eighty-five per cent reported mixing drugs and/or alcohol, 35% driving on drugs, 36% having a bad experience on drugs; 30% unprotected sex; and 0.9% injecting drugs. Women in the sample reported higher consumption than men.ConclusionsDance-drug use has a characteristic pattern that has implications for health promotion and criminal policy.

keywords:
Humans, Substance-Related Disorders, Prevalence, Risk-Taking, Sex Distribution, Dancing, Adolescent, Adult, Middle Aged, Scotland, Female, Male, Illicit Drugs

raw_json:
{"europe_pmc_id":"11440614","source":"MED","pub_type":null,"publisher":null,"importer":"Europe PMC"}


title: Drug addiction. Part I. Psychoactive substances in the past and presence.
authors: Vetulani J.
publication_date: 2001-04-30
pubmed_id: 11785921
source_url: https://europepmc.org/article/MED/11785921
substance_tags: psilocybin
topic_tags: Addiction,Consciousness,Review Article
study_type: Review Article
source_name: Europe PMC
publication_status: published
date_added: 2026-07-01 06:54:14
last_checked: 2026-07-01 11:22:07
abstract:
Substances capable of changing the functions of the central nervous system are widely distributed in plant kingdom, and many of them were discovered by ancient food-gatherers at the dawn of humanity. In the Old World only a few substances producing euphoria or altered states of consciousness and having habit-forming properties are still widely used. They are the products of poppy (opium, morphine), hemp (hashish, marijuana), and of fermentation of various organic materials alkohol. This list has recently been joined by the psilocybin-containing mushrooms. The addiction-forming compounds originated in the New World and widely spread are tobacco (nicotine) and cocaine. In the 19th and 20th, century the development of medicinal chemistry resulted in several synthetic compounds, originally proposed as therapeutics, such as barbiturates, benzodiazepines and amphetamines. Due to legal problems, to avoid production of the substances already prohibited, many designer drugs were manufactured. In addition, several compounds were synthesized as recreational drugs. Also some compounds that were not regarded as drugs, such as aromatic hydrocarbons and other cleansing agents, as well as steroids were found to have properties of dangerous, habit-forming agents. The attitude of society and the pattern of use of psychoactive substances have changed with time, particularly in the last decades. The active principles are now more addictive because of concentration, purification, chemical modifications and the way of ingestion, which now favors most rapid transport to the central nervous system. The substance abuse approaches the level of global epidemics, and the recent usage of drugs of addition is also reviewed.

keywords:
Humans, Substance-Related Disorders, Central Nervous System Agents, Psychotropic Drugs, Plant Preparations, Designer Drugs, Anabolic Agents, Western World, History, Ancient, History, 19th Century, History, 20th Century, Illicit Drugs

raw_json:
{"europe_pmc_id":"11785921","source":"MED","pub_type":null,"publisher":null,"importer":"Europe PMC"}


title: The effect of Psilocybe cubensis extract on hippocampal neurons in vitro.
authors: Moldavan MG, Grodzinskaya AA, Solomko EF, Lomberh ML, Wasser SP, Storozhuk VM.
publication_date: 2000-12-31
pubmed_id: 11962085
source_url: https://europepmc.org/article/MED/11962085
substance_tags: psilocybin,psilocin
topic_tags: Neuroplasticity,Receptor Pharmacology,Animal Study,In Vitro Study
study_type: Animal Study
source_name: Europe PMC
publication_status: published
date_added: 2026-07-01 06:54:14
last_checked: 2026-07-01 11:22:06
abstract:
The action of P. cubensis mushroom extract, containing psilocybin (PCB) and psilocin, on spike activity of hippocampal CA1 pyramidal neurons was studied in in vitro rat brain slices. In 38 (76%) out of 50 investigated neurons spike activity was decreased, in 2 (4%) cells it increased. There was no response 10 (20%) neurons. Application of the extract caused short burst firing in 12 (24%) neurons. All neurons showing inhibition during PCB-containing extract application, were also inhibited by serotonin (5-HT). Usually inhibitory reaction did not last over 4-5 min upon 3 min extract application and could be prolonged up to 10-43 min up on serotonin application. Part of neurons were inhibited by serotonin and did not react to extract application. Inhibitory reactions induced by extract application were blocked by ritanserin in half of the tested units and were induced due to activation of 5-HT2 serotonin receptors. The extract suppressed excitative spike reactions caused by application of L-glutamic acid. It is concluded, that application of PCB-containing extract in most cases reduced spike activity in hippocampal CA1 pyramidal neurons and suppressed glutamate transmission.

keywords:
Hippocampus, Neurons, Animals, Rats, Rats, Wistar, Agaricales, Serotonin, Glutamic Acid, Hallucinogens, Synaptic Transmission, Action Potentials, Neural Inhibition, Psilocybin

raw_json:
{"europe_pmc_id":"11962085","source":"MED","pub_type":null,"publisher":null,"importer":"Europe PMC"}


authors: Salomé F, Boyer P, Fayol M.
publication_date: 2000-11-30
doi: 10.1016/s0924-9338(00)00520-4
pubmed_id: 11175923
source_url: https://doi.org/10.1016/s0924-9338(00)00520-4
substance_tags: psilocybin
topic_tags: Pharmacology,Review Article,Observational Study
study_type: Review Article
source_name: Europe PMC
publication_status: published
date_added: 2026-07-01 06:54:14
last_checked: 2026-07-01 11:22:07
title:
The effects of psychoactive drugs and neuroleptics on language in normal subjects and schizophrenic patients: a review.

abstract:
The aim of this survey is to present an overview of research into psychopharmacology as regards the effects of different psychoactive drugs and neuroleptics (NL) on language in normal subjects and schizophrenic patients. Eighteen studies that have investigated the effects of different drugs (alcohol, amphetamines, secobarbital, L-dopa, psilocybin, ketamine, fenfluramine) and neuroleptics (conventional and atypical) on language are reviewed. There are no studies concerning the effects of neuroleptics on language in healthy subjects. The results of the effects of other molecules indicate that language production can be increased (alcohol, amphetamine, secobarbital), rendered more complex (d-amphetamine), more focused (L-dopa) or more unfocused (psilocybin) and clearly impaired (ketamine). For schizophrenic patients, most studies show that conventional neuroleptic treatments, at a therapeutic dosage and in acute or chronic mode, reduce language disorders at all levels (clinic, linguistic, psycholinguistic). In conjunction with other molecules, the classical NL, when administered at a moderate dosage and in chronic mode, modify language in schizophrenia, either by improving the verbal flow and reducing pauses and positive thought disorder (NL + amphetamine) or by inducing an impairment in the language measurements (NL + fenfluramine). Clinical, methodological and theoretical considerations of results are debated in the framework of schizophrenic language disorders.

keywords:
Brain, Humans, Psychotropic Drugs, Language, Verbal Behavior, Thinking, Psycholinguistics, Schizophrenia, Adult

raw_json:
{"europe_pmc_id":"11175923","source":"MED","pub_type":null,"publisher":null,"importer":"Europe PMC"}


title: Effect of ring fluorination on the pharmacology of hallucinogenic tryptamines.
authors: Blair JB, Kurrasch-Orbaugh D, Marona-Lewicka D, Cumbay MG, Watts VJ, Barker EL, Nichols DE.
publication_date: 2000-10-31
doi: 10.1021/jm000339w
pubmed_id: 11101361
source_url: https://doi.org/10.1021/jm000339w
substance_tags: psilocin
topic_tags: Pharmacology,Receptor Pharmacology,Animal Study,In Vitro Study
study_type: Animal Study
source_name: Europe PMC
publication_status: published
date_added: 2026-07-01 06:54:14
last_checked: 2026-07-01 11:22:07
abstract:
A series of fluorinated analogues of the hallucinogenic tryptamines N,N-diethyltryptamine (DET), 4-hydroxy-N,N-dimethyltryptamine (4-OH-DMT, psilocin), and 5-methoxy-DMT was synthesized to investigate possible explanations for the inactivity of 6-fluoro-DET as a hallucinogen and to determine the effects of fluorination on the molecular recognition and activation of these compounds at serotonin receptor subtypes. The target compounds were evaluated using in vivo behavioral assays for hallucinogen-like and 5-HT(1A) agonist activity and in vitro radioligand competition assays for their affinity at 5-HT(2A), 5-HT(2C), and 5-HT(1A) receptor sites. Functional activity at the 5-HT(2A) receptor was determined for all compounds. In addition, for some compounds functional activity was determined at the 5-HT(1A) receptor. Hallucinogen-like activity, evaluated in the two-lever drug discrimination paradigm using LSD-trained rats, was attenuated or abolished for all of the fluorinated analogues. One of the tryptamines, 4-fluoro-5-methoxy-DMT (6), displayed high 5-HT(1A) agonist activity, with potency greater than that of the 5-HT(1A) agonist 8-OH-DPAT. The ED(50) of 6 in the two-lever drug discrimination paradigm using rats trained to discriminate the 5-HT(1A) agonist LY293284 was 0.17 micromol/kg, and the K(i) at [(3)H]8-OH-DPAT-labeled 5-HT(1A) receptors was 0.23 nM. The results indicate that fluorination of hallucinogenic tryptamines generally has little effect on 5-HT(2A/2C) receptor affinity or intrinsic activity. Affinity at the 5-HT(1A) receptor was reduced, however, in all but one example, and all of the compounds tested were full agonists but with reduced functional potency at this serotonin receptor subtype. The one notable exception was 4-fluoro-5-methoxy-DMT (6), which had markedly enhanced 5-HT(1A) receptor affinity and functional potency. Although it is generally considered that hallucinogenic activity results from 5-HT(2A) receptor activation, the present results suggest a possible role for involvement of the 5-HT(1A) receptor with tryptamines.

keywords:
CHO Cells, 3T3 Cells, Animals, Humans, Mice, Rats, Fluorine, Tryptamines, Phosphatidylinositols, Receptors, Serotonin, Receptors, Serotonin, 5-HT1, Receptor, Serotonin, 5-HT2A, Receptor, Serotonin, 5-HT2C, Cyclic AMP, Hallucinogens, Radioligand Assay, Drug Evaluation, Preclinical, Discrimination Learning, Binding, Competitive, Structure-Activity Relationship, Hydrolysis, Cricetinae, Serotonin Receptor Agonists, Colforsin

raw_json:
{"europe_pmc_id":"11101361","source":"MED","pub_type":null,"publisher":null,"importer":"Europe PMC"}


title: Hallucinogenic drugs attenuate the subjective response to alcohol in humans.
authors: Barrett SP, Archambault J, Engelberg MJ, Pihl RO.
publication_date: 2000-09-30
doi: 10.1002/1099-1077(200010)15:7<559::aid-hup230>3.0.co;2-j
pubmed_id: 12404626
source_url: https://doi.org/10.1002/1099-1077(200010)15:7<559::aid-hup230>3.0.co;2-j
substance_tags: psilocybin
topic_tags: Receptor Pharmacology,Drug Interactions
study_type: Other
source_name: Europe PMC
publication_status: published
date_added: 2026-07-01 06:54:14
last_checked: 2026-07-01 11:22:07
abstract:
This study investigated possible interactions between alcohol and hallucinogens in 22 lysergic acid diethylamide (LSD) and/or psilocybin users through retrospective structured interviews. Of those who had used LSD with alcohol, 86;7 per cent reported a complete blockade of subjective alcohol effects, while the remaining cases reported a diminished response. In addition, 60 per cent of respondents who had used alcohol and psilocybin together reported a partial antagonism of subjective alcohol effects.T-test analyses revealed that LSD's antagonism of alcohol effects were significantly greater than those associated with psilocybin. It is proposed that LSD's effect on alcohol intoxication may involve interactions with various serotonergic and/or dopaminergic receptor systems. Copyright 2000 John Wiley & Sons, Ltd.

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title: [Intoxications by hallucinogenic mushrooms].
authors: Pierrot M, Josse P, Raspiller MF, Goulmy M, Rambourg MO, Manel J, Lambert H.
publication_date: 2000-09-30
pubmed_id: 11104939
source_url: https://europepmc.org/article/MED/11104939
keywords: Humans, Mushroom Poisoning, Hallucinogens, Follow-Up Studies, Time Factors, Adult, Male, Psilocybin
substance_tags: psilocybin,psilocin
topic_tags: Review Article,Adolescents
study_type: Review Article
source_name: Europe PMC
publication_status: published
date_added: 2026-07-01 06:54:14
last_checked: 2026-07-01 11:22:06
abstract:
In the context of excessive use of natural or synthetic psychoactive substances, with stimulating, psychedelic and hallucinogenic effects, an increase, if not a recurrence, in consumption of Psilocybe semilanceata has been observed in France over some fifteen years. Psilocybin and psilocin are the active compounds, responsible for the hallucinogenic effects and are a part of the substance group, derived from tryptamine and characterized by an indole nucleus. We report a clinical case observed in an emergency unit and review the historical, epidemiological and pharmacological data now available for these intoxications. Of particular interests in hallucinogenic mushroom abuse are: increased consumption in the context of youth cultural and entertainment movements; possible difficulties in the diagnosis in emergency conditions; possibility of severe and fatal complications.

raw_json:
{"europe_pmc_id":"11104939","source":"MED","pub_type":null,"publisher":null,"importer":"Europe PMC"}


authors: Bogusz MJ.
publication_date: 2000-09-30
doi: 10.1016/s0378-4347(00)00461-8
pubmed_id: 11092582
source_url: https://doi.org/10.1016/s0378-4347(00)00461-8
substance_tags: psilocybin,psilocin
topic_tags: Addiction
study_type: Clinical Trial
source_name: Europe PMC
publication_status: published
date_added: 2026-07-01 06:54:14
last_checked: 2026-07-01 11:22:06
title:
Liquid chromatography-mass spectrometry as a routine method in forensic sciences: a proof of maturity.

abstract:
The applications of LC-API-MS in routine forensic toxicological casework were presented. This technique has been used for routine determination of several groups of drugs: opiate agonists (like morphine, codeine, dihydrocodeine and their glucuronides, methadone, buprenorphine) cocaine and its metabolites (benzoylecgonine and ecgonine methyl ester), amphetamine and other psychoactive phenethylamines, like MDMA, MDE or MDA, benzodiazepine derivatives (flunitrazepam and metabolites, triazolam, bromazepam), hallucinogens (LSD, psilocybin, psilocin) and olanzapine, A common solid-phase extraction procedure for all drugs (with exception of LSD) has been developed. Among two ionization sources, atmospheric pressure chemical ionization appeared more universal and assured generally higher sensitivity. Only in the case of very polar drugs (e.g. psilocin or psilocybin) electrospray ionization was more sensitive. LC-API-MS became a very powerful and flexible method for dedicated analyses of substances of forensic interest. The use of this technique for general, broad applicable screening depends on the establishing of interlaboratory database of standardized mass spectra.

keywords:
Humans, Pharmaceutical Preparations, Chromatography, High Pressure Liquid, Forensic Medicine, Atmospheric Pressure, Mass Spectrometry

raw_json:
{"europe_pmc_id":"11092582","source":"MED","pub_type":null,"publisher":null,"importer":"Europe PMC"}


authors: Musshoff F, Madea B, Beike J.
publication_date: 2000-08-31
doi: 10.1016/s0379-0738(00)00211-5
pubmed_id: 10978653
source_url: https://doi.org/10.1016/s0379-0738(00)00211-5
substance_tags: psilocybin,psilocin
topic_tags: Toxicity
study_type: Other
source_name: Europe PMC
publication_status: published
date_added: 2026-07-01 06:54:14
last_checked: 2026-07-01 11:22:06
title:
Hallucinogenic mushrooms on the German market - simple instructions for examination and identification.

abstract:
'Magic mushrooms' is the name most commonly given to psychoactive fungi containing the hallucinogenic components psilocybin and psilocin. Material confiscated by local authorities was examined using morphologic, microscopic, microchemical, and toxicological methods. Psilocybe cubensis was the most popular mushroom in the sample collective, followed by Psilocybe semilanceata, Panaeolus cyanescens and Psilocybe tampanensis. The alkaloid content was determined with

keywords:
Humans, Agaricales, Substance-Related Disorders, Hallucinogens, Chromatography, Liquid, Substance Abuse Detection, Toxicology, Drug and Narcotic Control, Germany, Psilocybin

raw_json:
{"europe_pmc_id":"10978653","source":"MED","pub_type":null,"publisher":null,"importer":"Europe PMC"}


title: Bufotenine: toward an understanding of possible psychoactive mechanisms.
authors: McBride MC.
publication_date: 2000-06-30
doi: 10.1080/02791072.2000.10400456
pubmed_id: 11061684
source_url: https://doi.org/10.1080/02791072.2000.10400456
keywords: Blood-Brain Barrier, Humans, Serotonin, Bufotenin, Receptors, Serotonin, Psychotropic Drugs
substance_tags: psilocin
topic_tags: Pharmacology,Mechanism of Action,Receptor Pharmacology,Review Article
study_type: Review Article
source_name: Europe PMC
publication_status: published
date_added: 2026-07-01 06:54:14
last_checked: 2026-07-01 11:22:07
abstract:
A review of the neuropharmacology of the alleged hallucinogen bufotenine is presented, including recent experimental results showing activity similar to LSD and other known hallucinogens (psilocin and 5-MeO-DMT) at the purported hallucinogenic serotonin (5-HT) receptors, 5-HT2A and 5-HT2C. In addition, current reports of computer modeling of the receptors and ligand binding sites give evidence of bufotenine's ability to bind and activate these receptors. While binding and activation of the purported hallucinogenic receptors are not the full extent of the hallucinogenic signature, this evidence shows support for the rationale that the reported lack of the drug's classic hallucinogenic response in human experiments is due to poor ability to cross the blood brain barrier (BBB), not lack of activation of the appropriate brain receptors. Further evidence is reviewed that in some physiological states, some drugs with characteristics similar to bufotenine which do not normally cross the BBB, cross it and enter the brain. While direct human experimental evidence of bufotenine's hallucinogenic activity seems lacking, the above combined factors are considered, and possible explanations of bufotenine's reported psychoactivity are suggested. Additionally, updated experimental models testing the possible nature of bufotenine's hallucinogenic potential are proposed.

raw_json:
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authors: Adlaf EM, Paglia A, Ivis FJ, Ialomiteanu A.
publication_date: 2000-05-31
pubmed_id: 10870495
source_url: https://europepmc.org/article/MED/10870495
substance_tags: psilocybin
topic_tags: Addiction,Observational Study,Adolescents,Safety
study_type: Observational Study
source_name: Europe PMC
publication_status: published
date_added: 2026-07-01 06:54:14
last_checked: 2026-07-01 11:22:07
title:
Nonmedical drug use among adolescent students: highlights from the 1999 Ontario Student Drug Use Survey.

abstract:
BackgroundDuring the 1990s, rates of nonmedical drug use among adolescents escalated. We assessed data from 5 cycles of the Ontario Student Drug Use Survey for overall trends in the proportion of students reporting illegal drug use between 1991 and 1999.MethodsThe survey is a repeated, cross-sectional, 2-stage cluster-design survey of students enrolled in grades 7, 9, 11 and 13. Outcome measures were prevalence of use of 17 drugs, including alcohol and tobacco, over the 12 months preceding the survey.ResultsThe rates of drug use increased between 1993 and 1999. The 95% confidence intervals (CIs) for the differences in proportions between 1997 and 1999 indicated significant increases in the overall use of 6 drugs: alcohol (95% CIdiff 6.1, 1.9-10.3), cannabis (95% CIdiff 46.3, 0.2-8.4), glue (95% CIdiff 2.3, 1.3-3.3), other solvents (95% CIdiff 5.0, 3.1-6.3), barbiturates (95% CIdiff 1.9, 0.4-3.4) and hallucinogens such as mescaline and psilocybin (95% CIdiff 3.5, 0.8-6.9). Fewer grade 7 students in 1999 than in earlier cohorts reported using alcohol or cigarettes by age 9.InterpretationThe public health implications of the findings are mixed. On the positive side, there is no evidence of increases in early onset of drug use. On the negative side, the overall proportion of students reporting illegal drug use has continued to rise.

keywords:
Humans, Substance-Related Disorders, Health Surveys, Population Surveillance, Prevalence, Cluster Analysis, Confidence Intervals, Risk Factors, Cross-Sectional Studies, Students, Adolescent, Ontario, Female, Male

raw_json:
{"europe_pmc_id":"10870495","source":"MED","pub_type":null,"publisher":null,"importer":"Europe PMC"}


title: Detecting psychoactive drugs in the developmental stages of mushrooms.
authors: Gross ST.
publication_date: 2000-04-30
doi: 10.1520/jfs14725j
pubmed_id: 10855955
source_url: https://doi.org/10.1520/jfs14725j
substance_tags: psilocybin
topic_tags: General
study_type: Other
source_name: Europe PMC
publication_status: published
date_added: 2026-07-01 06:54:14
last_checked: 2026-07-01 11:22:07
abstract:
The following questions regarding the detection of psychoactive drugs in mushrooms are addressed: At what stage of the mushroom development can the psychoactive drugs psilocyn and psilocybin be identified, and what effect does light have on the growth of these mushrooms. To answer these questions, Psilocybe cyanescens Wakefield mushrooms were grown from their spores in a controlled setting. At various times of their development, samples were taken and analyzed for psilocyn and psilocybin. Knowing what stage of development the psychoactive drugs can be identified may be useful to law enforcement personnel and forensic chemists. Methanolic extracts of various samples were analyzed by TLC and by GC/MS. It was determined that the mycelium knot stage of the mushroom was the earliest stage at which the psychoactive drugs could be detected. It was observed that light affected the time of development and the appearance of these mushrooms.

keywords:
Agaricales, Psychotropic Drugs, Chromatography, Thin Layer, Sensitivity and Specificity, Forensic Medicine, Gas Chromatography-Mass Spectrometry

raw_json:
{"europe_pmc_id":"10855955","source":"MED","pub_type":null,"publisher":null,"importer":"Europe PMC"}


authors: Yamada F.
publication_date: 2000-03-31
doi: 10.1248/yakushi1947.120.4_363
pubmed_id: 10774258
source_url: https://doi.org/10.1248/yakushi1947.120.4_363
keywords: Alkaloids, Indoles, Chemistry, Organic
substance_tags: psilocin
topic_tags: General
study_type: Other
source_name: Europe PMC
publication_status: published
date_added: 2026-07-01 06:54:14
last_checked: 2026-07-01 11:22:07
title:
[Development of synthetic methods for 4-substituted indoles and their applications for the syntheses of natural products].

abstract:
In our continuing work on synthesizing 4-substituted indole alkaloids as simple as possible by creating suitable reactions, we developed synthetic methods for 4-substituted indoles having a nitrogen or oxygen functional group at the 4-position starting from indole-3-carbaldehyde and one step conversion method of indole-3-carbaldehydes into indole-3-acetonitriles. Utilizing them, we could establish a practical synthetic route to 1,3,4,5-tetrahydropyrrolo[4,3,2-de]-quinoline in three steps from indole-3-carbaldehyde. On the basis of these results, short step total syntheses of marine indole alkaloids, such as isobatzelline C, batzelline C, makaluvamine A, and damirones A and B, were achieved. Furthermore, a novel preparative method of psilocin was established in only five steps from indole-3-carbaldehyde. The syntheses of psilocin analogs having a formyl group or bromine in the benzene part were also achieved.

raw_json:
{"europe_pmc_id":"10774258","source":"MED","pub_type":null,"publisher":null,"importer":"Europe PMC"}


title: [Microscopic study of powders of hallucinogenic mushrooms--Psilocybe sp].
authors: Schäfer AT.
publication_date: 1999-12-31
pubmed_id: 10726173
source_url: https://europepmc.org/article/MED/10726173
keywords: Humans, Spores, Agaricales, Hallucinogens, Powders, Microscopy, Psilocybin
substance_tags: psilocybin
topic_tags: General
study_type: Other
source_name: Europe PMC
publication_status: published
date_added: 2026-07-01 06:54:14
last_checked: 2026-07-01 11:22:07
abstract:
The paper presents simple methods for microscopic examination and basic microchemical testing for the identification of suspect mushroom powders. The microscopic features of the most commonly cultivated and trafficked hallucinogenic genus Psilocybin are described and may serve for the decision whether any suspect material consists of such mushroom powder (and is therefore to be subjected to further analysis) or not.

raw_json:
{"europe_pmc_id":"10726173","source":"MED","pub_type":null,"publisher":null,"importer":"Europe PMC"}


title: Chromatographic screening techniques in systematic toxicological analysis.
authors: Drummer OH.
publication_date: 1999-09-30
doi: 10.1016/s0378-4347(99)00265-0
pubmed_id: 10572973
source_url: https://doi.org/10.1016/s0378-4347(99)00265-0
keywords: Humans, Pharmaceutical Preparations, Specimen Handling, Chromatography, Toxicology
substance_tags: psilocin
topic_tags: Review Article,Toxicity
study_type: Clinical Trial
source_name: Europe PMC
publication_status: published
date_added: 2026-07-01 06:54:14
last_checked: 2026-07-01 11:22:07
abstract:
A review of techniques used to screen biological specimens for the presence of drugs was conducted with particular reference to systematic toxicological analysis. Extraction systems of both the liquid-liquid and solid-phase type show little apparent difference in their relative ability to extract a range of drugs according to their physio-chemical properties, although mixed-phase SPE extraction is a preferred technique for GC-based applications, and liquid-liquid were preferred for HPLC-based applications. No one chromatographic system has been shown to be capable of detecting a full range of common drugs of abuse, and common ethical drugs, hence two or more assays are required for laboratories wishing to cover a reasonably comprehensive range of drugs of toxicological significance. While immunoassays are invariably used to screen for drugs of abuse, chromatographic systems relying on derivatization and capable of extracting both acidic and basic drugs would be capable of screening a limited range of targeted drugs. Drugs most difficult to detect in systematic toxicological analysis include LSD, psilocin, THC and its metabolites, fentanyl and its designer derivatives, some potent opiates, potent benzodiazepines and some potent neuroleptics, many of the newer anti-convulsants, alkaloids colchicine, amantins, aflatoxins, antineoplastics, coumarin-based anti-coagulants, and a number of cardiovascular drugs. The widespread use of LC-MS and LC-MS-MS for specific drug detection and the emergence of capillary electrophoresis linked to MS and MS-MS provide an exciting possibility for the future to increase the range of drugs detected in any one chromatographic screening system.

raw_json:
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authors: Gerasimov M, Marona-Lewicka D, Kurrasch-Orbaugh DM, Qandil AM, Nichols DE.
publication_date: 1999-09-30
doi: 10.1021/jm990325u
pubmed_id: 10514296
source_url: https://doi.org/10.1021/jm990325u
substance_tags: psilocin
topic_tags: Pharmacology,Receptor Pharmacology,In Vitro Study
study_type: In Vitro Study
source_name: Europe PMC
publication_status: published
date_added: 2026-07-01 06:54:14
last_checked: 2026-07-01 11:22:07
title:
Further studies on oxygenated tryptamines with LSD-like activity incorporating a chiral pyrrolidine moiety into the side chain.

abstract:
The enantiomers of 3-(N-methylpyrrolidin-2-ylmethyl)-5-methoxyindole, 1, and 3-(N-methylpyrrolidin-2-ylmethyl)-4-hydoxyindole, 3, were prepared using an asymmetric synthesis that employed (+)- or (-)-proline. A new approach was developed that had certain advantages over the synthesis originally reported for the isomers of 1. (+/-)-3-(N-Methylpyrrolidin-3-yl)-4-hydroxyindole, 5, was also prepared as a rigid analogue of psilocin and compared with its 5-methoxy counterpart 4. Radioligand competition assays were used to assess the affinity of compounds for the 5-HT(2A) receptor labeled with the agonist ligand [(125)I]DOI and the antagonist ligand [(3)H]MDL100907. Two-lever drug discrimination assays in rats trained to discriminate either LSD or DOI from saline were employed to assess the hallucinogen-like behavioral properties of these rigid tryptamine analogues. The receptor binding assay results clearly demonstrated a stereochemical preference for the R enantiomers that did not discriminate the position of the oxygen function. The receptor is 10-20-fold more selective for the R isomers. The affinities of the R enantiomers were virtually identical for both 1 and 3 at the agonist-labeled receptor, while racemic 4 and 5 had about one-tenth the affinity. The drug discrimination data in both LSD- and DOI-trained rats paralleled the binding data using [(125)I]DOI displacement. Both (R)-1 and (R)-3 are about equipotent, comparable to DOI in activity but about 10-fold less potent than LSD. Compound 4 produced only partial substitution, even at a dose nearly 5-fold higher than for (R)-1. Based on conformational energies, it seems doubtful that these compounds bind to the 5-HT(2A) receptor in an ergoline-like conformation. The results also suggest that both 1 and 3 would possess LSD-like psychopharmacology in humans.

keywords:
Frontal Lobe, Animals, Rats, Rats, Sprague-Dawley, Tryptamines, Lysergic Acid Diethylamide, Pyrrolidines, Indoles, Receptors, Serotonin, Receptor, Serotonin, 5-HT2A, Radioligand Assay, Discrimination Learning, Binding, Competitive, Structure-Activity Relationship, Stereoisomerism, Male, In Vitro Techniques

raw_json:
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authors: Krämer E, Kovar KA.
publication_date: 1999-07-31
doi: 10.1016/s0378-4347(99)00212-1
pubmed_id: 10510769
source_url: https://doi.org/10.1016/s0378-4347(99)00212-1
substance_tags: psilocin
topic_tags: General
study_type: Clinical Trial
source_name: Europe PMC
publication_status: published
date_added: 2026-07-01 06:54:14
last_checked: 2026-07-01 11:22:07
title:
On-line coupling of automated solid-phase extraction with high-performance liquid chromatography and electrochemical detection. Quantitation of oxidizable drugs of abuse and their metabolites in plasma and urine.

abstract:
The concentration effect of automated on-line solid-phase extraction (SPE) in combination with HPLC and very sensitive electrochemical detection was employed for the determination of N-ethyl-4-hydroxy-3-methoxy-amphetamine (HMEA, the main metabolite of the ecstasy analogue MDE), delta 9-tetrahydrocannabinol (THC) and 11-nor-delta 9-tetrahydrocannabinol-carboxylic acid (THC-COOH) in plasma and urine in comparison to a previously published psilocin assay. For the SPE either CBA (functional group: carboxypropyl)- or CH (functional group: cyclohexyl)-sorbent was used. The following separation was carried out on a reversed-phase column (LiChroCart, Superspher 60 RP select B from Merck). Depending on the hydrodynamic voltammogram of the analyzed substance the oxidation potential varied from 920 mV up to 1.2 V. In spite of using high potentials, precision and accuracy were always within the accepted statistical requirements. The limits of quantitation were between 5 ng/ml (THC, THC-COOH in plasma) and 20 ng/ml (HMEA in plasma). Advantages of on-line SPE in comparison with off-line methods were less manual effort, evidently smaller volumes (< or = 400 microliters) of plasma or urine and almost always higher recovery rates (> 93%). The assays have been successfully proven with real biological samples and found suitable for use in routine analysis.

keywords:
Humans, Amphetamines, Chromatography, High Pressure Liquid, Reproducibility of Results, Electrochemistry, Automation, Dronabinol, Illicit Drugs

raw_json:
{"europe_pmc_id":"10510769","source":"MED","pub_type":null,"publisher":null,"importer":"Europe PMC"}


title: [Biological addictive drugs--is there a change in drug taking behavior of young drug addicts?].
authors: Löhrer F, Albers M.
publication_date: 1999-06-30
pubmed_id: 10457973
source_url: https://europepmc.org/article/MED/10457973
substance_tags: psilocybin
topic_tags: General
study_type: Other
source_name: Europe PMC
publication_status: published
date_added: 2026-07-01 06:54:14
last_checked: 2026-07-01 11:22:07
abstract:
Abuse of natural products was frequently noticed among young patients with multiple substance abuse. 180 patients of a rehabilitation clinic for young addicts filled out a questionnaire regarding their regularly consumed drugs. Ayahuasca and cactus, the natural drugs of the 70's are rarely found. The patients frequently consumed psilocybin, amanita and datura. We inform about the toxicological basis of the used drugs. A specific exploration of patients with multiple substance abuse in regard to the use of biological drugs is an necessary as random and multicentre follow-up-studies.

keywords:
Humans, Substance-Related Disorders, Psychotropic Drugs, Plant Extracts, Incidence, Cross-Sectional Studies, Health Education, Adult, Germany, Female, Male

raw_json:
{"europe_pmc_id":"10457973","source":"MED","pub_type":null,"publisher":null,"importer":"Europe PMC"}


publication_date: 1999-05-31
doi: 10.1016/s0893-133x(98)00089-x
pubmed_id: 10327426
source_url: https://doi.org/10.1016/s0893-133x(98)00089-x
substance_tags: psilocybin
topic_tags: Brain Imaging,Pharmacology,Mechanism of Action,Aging,Healthy Volunteers,Drug Interactions
study_type: Other
source_name: Europe PMC
publication_status: published
date_added: 2026-07-01 06:54:14
last_checked: 2026-07-01 11:22:07
title:
Neurometabolic effects of psilocybin, 3,4-methylenedioxyethylamphetamine (MDE) and d-methamphetamine in healthy volunteers. A double-blind, placebo-controlled PET study with [18F]FDG.

authors:
Gouzoulis-Mayfrank E, Schreckenberger M, Sabri O, Arning C, Thelen B, Spitzer M, Kovar KA, Hermle L, Büll U, Sass H.

abstract:
The neurometabolic effects of the hallucinogen psilocybin (PSI; 0.2 mg/kg), the entactogen 3,4-methylenedioxyethylamphetamine (MDE; 2 mg/kg) and the stimulant d-methamphetamine (METH; 0.2-0.4 mg/kg) and the drugs' interactions with a prefrontal activation task were investigated in a double-blind, placebo-controlled human [F-18]fluorodeoxyglucoseFDG-positron emission tomographicPET study (each group: n = 8). Subjects underwent two scans (control: word repetition; activation word association) within 2-4 weeks. Psilocybin increased rMRGlu in distinct right hemispheric frontotemporal cortical regions, particularly in the anterior cingulate and decreased rMRGlu in the thalamus. Both MDE and METH induced cortical hypometabolism and cerebellar hypermetabolism. In the MDE group, cortical hypometabolism was more pronounced in frontal regions, with the exception of the right anterior cingulate, which tended to be hyperactive. Cognitive activation-related increases in left frontocortical regions were attenuated under all three psychoactive substances, but less so under MDE. Taking into account performance data and subjective reports on task difficulty, these effects may result from different mechanisms across the three groups. Our PSI data are in line with studies on acute schizophrenic patients suggesting frontal overactivity at rest, but diminished capacity to activate prefrontal regions upon cognitive demand. The MDE data support the hypothesis that entactogens constitute a distinct psychoactive substance class, which takes an intermediate position between stimulants and hallucinogens.

keywords:
Cerebellum, Humans, Methamphetamine, 3,4-Methylenedioxyamphetamine, Glucose, Adrenergic Agents, Hallucinogens, Nootropic Agents, Magnetic Resonance Imaging, Radionuclide Imaging, Double-Blind Method, Cognition, Psychopathology, Adult, Middle Aged, Female, Male, Psilocybin

raw_json:
{"europe_pmc_id":"10327426","source":"MED","pub_type":null,"publisher":null,"importer":"Europe PMC"}


authors: Babakhanian RV, Ivanova GV, Kostyrko TA, Safraĭ AE, Iagmurov OD.
publication_date: 1999-04-30
pubmed_id: 10396957
source_url: https://europepmc.org/article/MED/10396957
substance_tags: psilocybin
topic_tags: Pharmacology,Mitochondrial Function
study_type: Other
source_name: Europe PMC
publication_status: published
date_added: 2026-07-01 06:54:14
last_checked: 2026-07-01 11:22:07
title:
[The morphofunctional changes in the internal organs in the modelling of poisonings by psilocybine-containing mushrooms].

abstract:
Histological analysis of the viscera in experimental poisoning with psilocybin-containing mushrooms showed nonspecific changes in all examined organs, presenting as expressed hemocirculatory disorders and intracellular dystrophy. Quantitative histochemical analysis showed appreciable shifts in the activities of enzymes involved in the cytoplasmic and mitochondrial redox processes and of specific enzymes involved in nerve tissue metabolism. This may reflect some features in the direct effects of narcotic alkaloids contained in psilocybin-producing mushrooms.

keywords:
Viscera, Animals, Rats, Poisoning, Disease Models, Animal, Hallucinogens, Histocytochemistry, Analysis of Variance, Statistics, Nonparametric, Aggression, Male, Psilocybin

raw_json:
{"europe_pmc_id":"10396957","source":"MED","pub_type":null,"publisher":null,"importer":"Europe PMC"}


authors: Vollenweider FX, Vontobel P, Hell D, Leenders KL.
publication_date: 1999-04-30
doi: 10.1016/s0893-133x(98)00108-0
pubmed_id: 10192823
source_url: https://doi.org/10.1016/s0893-133x(98)00108-0
substance_tags: psilocybin
topic_tags: Receptor Pharmacology,Healthy Volunteers,Drug Interactions
study_type: Other
source_name: Europe PMC
publication_status: published
date_added: 2026-07-01 06:54:14
last_checked: 2026-07-01 11:22:06
title:
5-HT modulation of dopamine release in basal ganglia in psilocybin-induced psychosis in man--a PET study with [11C]raclopride.

abstract:
The modulating effects of serotonin on dopamine neurotransmission are not well understood, particularly in acute psychotic states. Positron emission tomography was used to examine the effect of psilocybin on the in vivo binding of [11C]raclopride to D2-dopamine receptors in the striatum in healthy volunteers after placebo and a psychotomimetic dose of psilocybin (n = 7). Psilocybin is a potent indoleamine hallucinogen and a mixed 5-HT2A and 5-HT1A receptor agonist. Psilocybin administration (0.25 mg/kg p.o.) produced changes in mood, disturbances in thinking, illusions, elementary and complex visual hallucinations and impaired ego-functioning. Psilocybin significantly decreased [11C]raclopride receptor binding potential (BP) bilaterally in the caudate nucleus (19%) and putamen (20%) consistent with an increase in endogenous dopamine. Changes in [11C]raclopride BP in the ventral striatum correlated with depersonalization associated with euphoria. Together with previous reports of 5-HT receptor involvement in striatal dopamine release, it is concluded that stimulation of both 5-HT2A and 5-HT1A receptors may be important for the modulation of striatal dopamine release in acute psychoses. The present results indirectly support the hypothesis of a serotonin-dopamine dysbalance in schizophrenia and suggest that psilocybin is a valuable tool in the analysis of serotonin-dopamine interactions in acute psychotic states.

keywords:
Basal Ganglia, Humans, Psychoses, Substance-Induced, Raclopride, Salicylamides, Dopamine, Serotonin, Dopamine Antagonists, Antipsychotic Agents, Hallucinogens, Tomography, Emission-Computed, Psychometrics, Adult, Male, Psilocybin

raw_json:
{"europe_pmc_id":"10192823","source":"MED","pub_type":null,"publisher":null,"importer":"Europe PMC"}


publication_date: 1999-01-31
doi: 10.1007/s002130050860
pubmed_id: 10102781
source_url: https://doi.org/10.1007/s002130050860
substance_tags: psilocybin
topic_tags: Emotional Processing,Healthy Volunteers
study_type: Clinical Trial
source_name: Europe PMC
publication_status: published
date_added: 2026-07-01 06:54:14
last_checked: 2026-07-01 11:22:07
title:
Psychopathological, neuroendocrine and autonomic effects of 3,4-methylenedioxyethylamphetamine (MDE), psilocybin and d-methamphetamine in healthy volunteers. Results of an experimental double-blind placebo-controlled study.

authors:
Gouzoulis-Mayfrank E, Thelen B, Habermeyer E, Kunert HJ, Kovar KA, Lindenblatt H, Hermle L, Spitzer M, Sass H.

abstract:
The aim of this study was to contribute to the characterization of the entactogen (ecstasy) substance group. The psychopathological, neuroendocrine and autonomic effects of common recreational doses of the entactogen 3,4-methylenedioxyethylamphetamine (MDE), the hallucinogen psilocybin, the stimulant d-methamphetamine and placebo were investigated in a double-blind study with healthy volunteers (n = 32). Psychological effects of the drugs were assessed by means of standardized rating scales, self assessment inventories and free descriptions. The most characteristic effects of MDE were pleasant emotional experiences of relaxation, peacefulness, content and closeness to others. However, significant stimulant and hallucinogen-like effects were also present, although the latter were weaker than the effects of psilocybin. MDE elicited the strongest endocrine and autonomic effects among the three drugs, including robust rises of serum cortisol and prolactin, elevations of blood pressure and heart rate, and a moderate, but significant rise of body temperature. The apparent contrast between psychological and autonomic effects (subjective relaxation versus physical activation) was a unique feature of the MDE state. Our findings are in line with both users' reports and results from previous experimental studies, and support the view that entactogens constitute a distinct psychoactive substance class taking an intermediate position between hallucinogens and stimulants.

keywords:
Neurosecretory Systems, Humans, Acute-Phase Reaction, Methamphetamine, 3,4-Methylenedioxyamphetamine, Central Nervous System Stimulants, Hallucinogens, Autonomic Agents, Double-Blind Method, Psychopathology, Adult, Aged, Middle Aged, Female, Male, Psilocybin

raw_json:
{"europe_pmc_id":"10102781","source":"MED","pub_type":null,"publisher":null,"importer":"Europe PMC"}


authors: Keller T, Schneider A, Regenscheit P, Dirnhofer R, Rücker T, Jaspers J, Kisser W.
publication_date: 1998-12-31
doi: 10.1016/s0379-0738(98)00168-6
pubmed_id: 10077856
source_url: https://doi.org/10.1016/s0379-0738(98)00168-6
substance_tags: psilocybin,psilocin
topic_tags: General
study_type: Other
source_name: Europe PMC
publication_status: published
date_added: 2026-07-01 06:54:14
last_checked: 2026-07-01 11:22:05
title:
Analysis of psilocybin and psilocin in Psilocybe subcubensis Guzmán by ion mobility spectrometry and gas chromatography-mass spectrometry.

abstract:
A new method has been developed for the rapid analysis of psilocybin and/or psilocin in fungus material using ion mobility spectrometry. Quantitative analysis was performed by gas chromatography-mass spectrometry after a simple one-step extraction involving homogenization of the dried fruit bodies of fungi in chloroform and derivatization with MSTFA. The proposed methods resulted in rapid procedures useful in analyzing psychotropic fungi for psilocybin and psilocin.

keywords:
Humans, Agaricales, Hallucinogens, Sensitivity and Specificity, Reproducibility of Results, Forensic Medicine, Drug and Narcotic Control, Mass Spectrometry, Gas Chromatography-Mass Spectrometry, Psilocybin

raw_json:
{"europe_pmc_id":"10077856","source":"MED","pub_type":null,"publisher":null,"importer":"Europe PMC"}


title: Psilocybin induces schizophrenia-like psychosis in humans via a serotonin-2 agonist action.
authors: Vollenweider FX, Vollenweider-Scherpenhuyzen MF, Bäbler A, Vogel H, Hell D.
publication_date: 1998-11-30
doi: 10.1097/00001756-199812010-00024
pubmed_id: 9875725
source_url: https://doi.org/10.1097/00001756-199812010-00024
substance_tags: psilocybin
topic_tags: Receptor Pharmacology
study_type: Other
source_name: Europe PMC
publication_status: published
date_added: 2026-07-01 06:54:14
last_checked: 2026-07-01 11:22:06
raw_json: {"europe_pmc_id":"9875725","source":"MED","pub_type":null,"publisher":null,"importer":"Europe PMC"}
abstract:
Psilocybin, an indoleamine hallucinogen, produces a psychosis-like syndrome in humans that resembles first episodes of schizophrenia. In healthy human volunteers, the psychotomimetic effects of psilocybin were blocked dose-dependently by the serotonin-2A antagonist ketanserin or the atypical antipsychotic risperidone, but were increased by the dopamine antagonist and typical antipsychotic haloperidol. These data are consistent with animal studies and provide the first evidence in humans that psilocybin-induced psychosis is due to serotonin-2A receptor activation, independently of dopamine stimulation. Thus, serotonin-2A overactivity may be involved in the pathophysiology of schizophrenia and serotonin-2A antagonism may contribute to therapeutic effects of antipsychotics.

keywords:
Humans, Ketanserin, Serotonin Antagonists, Hallucinogens, Analysis of Variance, Psychomotor Performance, Reaction Time, Schizophrenia, Neuropsychological Tests, Dose-Response Relationship, Drug, Reference Values, Adult, Female, Male, Serotonin Receptor Agonists, Psilocybin


title: [The forensic chemical study of psilocybine-containing fungi].
authors: Babakhanian RV, Bushuev ES, Zenkevich IG, Kazankov SP, Kostyrko TA, Kuz'minykh KS.
publication_date: 1998-10-31
pubmed_id: 9989170
source_url: https://europepmc.org/article/MED/9989170
substance_tags: psilocybin
topic_tags: General
study_type: Clinical Trial
source_name: Europe PMC
publication_status: published
date_added: 2026-07-01 06:54:14
last_checked: 2026-07-01 11:22:07
raw_json: {"europe_pmc_id":"9989170","source":"MED","pub_type":null,"publisher":null,"importer":"Europe PMC"}
abstract:
A method for isolating the main components (psilocybin and psilocine) from Psilocybe semilanceata mushrooms, their identification and measurement by thin-layer and gas-liquid chromatography, chromatographic mass-spectrometry, and inverse-phase high-performance liquid chromatography is developed.

keywords:
Agaricales, Hallucinogens, Chromatography, High Pressure Liquid, Chromatography, Thin Layer, Forensic Medicine, Gas Chromatography-Mass Spectrometry, Psilocybin


authors: Gouzoulis-Mayfrank E, Heekeren K, Thelen B, Lindenblatt H, Kovar KA, Sass H, Geyer MA.
publication_date: 1998-10-31
doi: 10.1097/00008877-199811000-00011
pubmed_id: 9862081
source_url: https://doi.org/10.1097/00008877-199811000-00011
substance_tags: psilocybin
topic_tags: Neuroplasticity,Animal Study
study_type: Other
source_name: Europe PMC
publication_status: published
date_added: 2026-07-01 06:54:14
last_checked: 2026-07-01 11:22:06
raw_json: {"europe_pmc_id":"9862081","source":"MED","pub_type":null,"publisher":null,"importer":"Europe PMC"}
title:
Effects of the hallucinogen psilocybin on habituation and prepulse inhibition of the startle reflex in humans.

abstract:
Schizophrenic patients exhibit deficits in indices of sensorimotor gating, such as habituation and prepulse inhibition (PPI) of the startle reflex. Hallucinogenic drug-induced states are putative models for the early and acute stages of schizophrenic and schizophrenia-spectrum disorders. Hallucinogenic drugs have been shown to disrupt PPI and/or retard habituation of the startle reflex in animal models of schizophrenia, consistent with the view of hallucinogen-induced states as 'model psychoses'. We evaluated the effects of the hallucinogen psilocybin on PPI and habituation of the startle reflex in a double-blind, placebo-controlled human study with 12 healthy subjects. In contrast to animal studies, in our small human sample, psilocybin increased PPI, while having no clear effect on habituation (n = 6). These findings must be considered preliminary because several factors, including dose regimens and experimental parameters, may influence the results of studies on startle plasticity. Further investigations both with psychotic patients in different stages of the disease and with human and animal models of schizophrenia are needed in order to explore the effects of hallucinogens on sensorimotor gating and the relationship between information processing in hallucinogenic drug-induced states and the naturally occurring psychoses.

keywords:
Humans, Hallucinogens, Electromyography, Double-Blind Method, Adult, Middle Aged, Female, Male, Habituation, Psychophysiologic, Reflex, Startle, Psilocybin, Inhibition, Psychological


title: Dr. Leary's Concord Prison Experiment: a 34-year follow-up study.
authors: Doblin R.
publication_date: 1998-09-30
doi: 10.1080/02791072.1998.10399715
pubmed_id: 9924845
source_url: https://doi.org/10.1080/02791072.1998.10399715
substance_tags: psilocybin
topic_tags: General
study_type: Other
source_name: Europe PMC
publication_status: published
date_added: 2026-07-01 06:54:14
last_checked: 2026-07-01 11:22:07
raw_json: {"europe_pmc_id":"9924845","source":"MED","pub_type":null,"publisher":null,"importer":"Europe PMC"}
abstract:
This study is a long-term follow-up to the Concord Prison Experiment, one of the best-known studies in the psychedelic psychotherapy literature. The Concord Prison Experiment was conducted from 1961 to 1963 by a team of researchers at Harvard University under the direction of Timothy Leary. The original study involved the administration of psilocybin-assisted group psychotherapy to 32 prisoners in an effort to reduce recidivism rates. This follow-up study involved a search through the state and federal criminal justice system records of 21 of the original 32 subjects, as well as personal interviews with two of the subjects and three of the researchers: Timothy Leary, Ralph Metzner and Gunther Weil. The results of the follow-up study indicate that published claims of a treatment effect were erroneous. This follow-up study supports the emphasis in the original reports on the necessity of embedding psilocybin-assisted psychotherapy with inmates within a comprehensive treatment plan that includes post-release, nondrug group support programs. Despite substantial efforts by the experimental team to provide post-release support, these services were not made sufficiently available to the subjects in this study. Whether a new program of psilocybin-assisted group psychotherapy and post-release programs would significantly reduce recidivism rates is an empirical question that deserves to be addressed within the context of a new experiment.

keywords:
Humans, Hallucinogens, Follow-Up Studies, Psychotherapy, Crime, History, 20th Century, Adult, Middle Aged, Prisoners, Male, Psilocybin


title: Recent findings from the Ontario Student Drug Use Survey.
authors: Adlaf EM, Ivis FJ.
publication_date: 1998-08-31
pubmed_id: 9757168
source_url: https://europepmc.org/article/MED/9757168
substance_tags: psilocybin
topic_tags: Addiction,Observational Study,Adolescents,Safety
study_type: Observational Study
source_name: Europe PMC
publication_status: published
date_added: 2026-07-01 06:54:14
last_checked: 2026-07-01 11:22:07
raw_json: {"europe_pmc_id":"9757168","source":"MED","pub_type":null,"publisher":null,"importer":"Europe PMC"}
abstract:
BackgroundEvery 2 years, the Addiction Research Foundation of Ontario, a division of the Centre for Addiction and Mental Health, sponsors the Ontario Student Drug Use Survey. The results of the surveys conducted in 1995 and 1997 are presented here and compared with results from the early 1990s.MethodsQuestionnaires were completed by 3870 and 3990 Ontario public school students enrolled in grades 7, 9, 11 and 13 in 1995 and 1997 respectively. The outcome measures were prevalence of use of 20 types of drugs and other substances, including alcohol, tobacco and prescription drugs, over the previous 12 months.ResultsFor several drugs the prevalence of use in the previous 12 months had increased from 1993 to 1995, but from 1995 to 1997 there was a significant increase for only one type (hallucinogens such as mescaline and psilocybin). The inhalation of glue declined, and the use of the other 18 types of drugs remained stable.InterpretationRecent data suggest that increases in adolescent student drug use reported earlier this decade have not continued. However, the stability in rates of drug use is not a justification for complacency in this important area of public health.

keywords:
Humans, Substance-Related Disorders, Health Surveys, Population Surveillance, Prevalence, Risk Factors, Cross-Sectional Studies, Students, Adolescent, Ontario, Female, Male, Surveys and Questionnaires


