Psilocybin and psilocin research index

Human Cortical Serotonin 2A Receptor Occupancy by Psilocybin Measured Using [11C]MDL100,907 Dynamic PET and a Resting-State fMRI-Based Brain Parcellation.

Psilocybin (a serotonin 2A, or 5-HT2A, receptor agonist) has shown preliminary efficacy as a treatment for mood and substance use disorders. The current report utilized positron emission tomography (PET) with the selective 5-HT2A receptor inverse agonist radioligand [11C]MDL100,907 (a.k.a. M100,907) and cortical regions of interest (ROIs) derived from restin...

The effects of psilocybin on cognitive and emotional functions in healthy participants: Results from a phase 1, randomised, placebo-controlled trial involving simultaneous psilocybin administration and preparation.

BackgroundPsilocybin, a psychoactive serotonin receptor partial agonist, has been reported to acutely reduce clinical symptoms of depressive disorders. Psilocybin's effects on cognitive function have not been widely or systematically studied.AimThe aim of this study was to explore the safety of simultaneous administration of psilocybin to healthy participant...

Neurochemical and behavioural characterisation of the psychedelic 5HT2AR agonist psilocybin in mice

Psychedelics as Novel Therapeutics in Alzheimer's Disease: Rationale and Potential Mechanisms.

Serotonin 2A receptor (5-HTR) agonist "classic psychedelics" are drawing increasing interest as potential mental health treatments. Recent work suggests psychedelics can exert persisting anxiolytic and antidepressant effects lasting up to several months after a single administration. Data indicate acute subjective drug effects as important psychological fact...

Serotonergic psychedelics for depression: What do we know about neurobiological mechanisms of action?

Current treatment options for major depressive disorder (MDD) have limited efficacy and are associated with adverse effects. Recent studies investigating the antidepressant effect of serotonergic psychedelics-also known as classic psychedelics-have promising preliminary results with large effect sizes. In this context, we conducted a review of the putative n...

Molecular Mechanisms of Psilocybin and Implications for the Treatment of Depression.

Therapeutic deficiencies with monoaminergic antidepressants invites the need to identify and develop novel rapid-acting antidepressants. Hitherto, ketamine and esketamine are identified as safe, well-tolerated rapid-acting antidepressants in adults with treatment-resistant depression, and also mitigate measures of suicidality. Psilocybin is a naturally occur...

[Rapid-acting antidepressants-neurobiological mechanisms of action].

Rapid-acting antidepressants disprove the dogma that antidepressants need several weeks to become clinically effective. Ketamine, the prototype of a rapid-acting antidepressant, is an N-methyl-D-aspartate (NMDA) receptor blocking agent. A single i.v. application of ketamine induces rapid changes in glutamatergic neurotransmitter systems, leading to preferent...

A Complex Impact of Systemically Administered 5-HT2A Receptor Ligands on Conditioned Fear.

BackgroundThough drugs binding to serotonergic 5-HT2A receptors have long been claimed to influence human anxiety, it remains unclear if this receptor subtype is best described as anxiety promoting or anxiety dampening. Whereas conditioned fear expressed as freezing in rats is modified by application of 5-HT2A-acting drugs locally into different brain region...

Psychedelics and psychiatric disorders: A emerging role

Introduction Recently there has been renewal in interest of psychedelic research. Classic psychedelics such as lysergic acid diethylamide (LSD), psilocybin and mescaline act pharmacologically as agonists at the 5-HT2A receptor. The entactogens like methylenedioxymethamphetamine (MDMA), acts as a serotonin, dopamine and noradrenaline agonist. All of these dru...

Psychedelics: A new era of treatment?

Introduction Psychedelics - including LSD (lysergic acid diethylamide), psilocybin, DMT (N, N-dimethyltryptamine), ayahuasca and mescaline - have an ancient history across various civilizations. In 1950, after LSD’s discovery by Hofmann, psychedelics enjoyed a short-lived relationship with psychiatry, before prohibitive legislature emerging in response to th...

Psilocybin in the treatment of obsessive-compulsive disorder: What do we know so far?

Introduction Psilocybin is a naturally occurring plant alkaloid in mushrooms and a prodrug of psilocin. It is a serotonin receptor (5-HT2A) agonist and known psychedelic, with similar hallucinatory properties to lysergic acid diethylamide (LSD). It has been identified as a safe and effective option in treatment-resistant depression. Literature focus mainly o...

Psychedelic-Assisted Psychotherapy for Post-Traumatic Stress Disorder, Anxiety Disorders, Mood Disorders, or Substance Use Disorders

Hallucinogens include many different drugs, which are often called “psychedelic” drugs. The US National Institute on Drug Abuse categorizes these drugs into 2 categories: classic hallucinogens and dissociative drugs. Both types of psychedelics can lead to hallucinations - sensations and images that seem real although they are imaginary. In addition, an indiv...

LSD and psilocybin flatten the brain’s energy landscape: insights from receptor-informed network control theory

Psychedelics like lysergic acid diethylamide (LSD) and psilocybin offer a powerful window into the function of the human brain and mind, by temporarily altering subjective experience through their neurochemical effects. A recent model postulates that serotonin 2a (5-HT2a) receptor agonism allows the brain to explore its dynamic landscape more readily, as ref...

Molecular and Functional Imaging Studies of Psychedelic Drug Action in Animals and Humans.

Hallucinogens are a loosely defined group of compounds including LSD, N,N-dimethyltryptamines, mescaline, psilocybin/psilocin, and 2,5-dimethoxy-4-methamphetamine (DOM), which can evoke intense visual and emotional experiences. We are witnessing a renaissance of research interest in hallucinogens, driven by increasing awareness of their psychotherapeutic pot...

Psilocybin in the treatment of obsessive-compulsive disorder: What do we know so far?

Introduction Psilocybin is a naturally occurring plant alkaloid in mushrooms and a prodrug of psilocin. It is a serotonin receptor (5-HT2A) agonist and known psychedelic, with similar hallucinatory properties to lysergic acid diethylamide (LSD). It has been identified as a safe and effective option in treatment-resistant depression. Literature focus mainly o...

5-HT2A and 5-HT2C receptors as potential targets for the treatment of nicotine use and dependence.

Nicotine use and dependence, typically achieved through cigarette smoking, but increasingly through vape products, is the leading cause of preventable death today. Despite a recognition that many current smokers would like to quit, the success rate at doing so is low and indicative of the persistent nature of nicotine dependence and the high urge to relapse....

A Single Dose of Psilocybin Increases Synaptic Density and Decreases 5-HT2A Receptor Density in the Pig Brain.

A single dose of psilocybin, a psychedelic and serotonin 2A receptor (5-HT2AR) agonist, may be associated with antidepressant effects. The mechanism behind its antidepressive action is unknown but could be linked to increased synaptogenesis and down-regulation of cerebral 5-HT2AR. Here, we investigate if a single psychedelic dose of psilocybin changes synapt...

What is the clinical evidence on psilocybin for the treatment of psychiatric disorders? A systematic review.

BackgroundPsilocybin is a predominant agonist of 5HT1A and 5HT2A/C receptors and was first isolated in 1958, shortly before it became a controlled substance. Research on the potential therapeutic effects of this compound has recently re-emerged alongside what is being addressed as a psychedelic renaissance.MethodsIn this paper we performed a systematic revie...

Set and Setting: A Randomized Study of Different Musical Genres in Supporting Psychedelic Therapy

Mounting evidence supports the serotonin 2A receptor agonist psilocybin as a psychiatric pharmacotherapy. Little research has experimentally examined how session “set and setting” impacts subjective and therapeutic effects. We analyzed effects of musical genre played during sessions of a psilocybin study for tobacco smoking cessation. Participants (N=10) rec...

Investigation of the Structure-Activity Relationships of Psilocybin Analogues

The 5-HT2A receptor is thought to be the primary target for psilocybin (4-phosphoryloxy-N,N-dimethyltryptamine) and other serotonergic hallucinogens (psychedelic drugs). Although a large amount of experimental work has been conducted to characterize the pharmacology of psilocybin and its dephosphorylated metabolite psilocin (4-hydroxy-N,N-dimethyltryptamine)...