"Iracema comes with the pot full of the green liquor. The shaman decrees the dreams to each warrior and distributes the wine of jurema, which carries the brave Tabajara to heaven." José de Alencar, in his poetic novel “Iracema” (1865)1. IntroductionThe "wine of jurema", used in ancient Brazilian shamanic rituals, is rich in N,N-dimethyltryptamine (DMT), a na...
In visual perception, an effect known as surround suppression occurs wherein the apparent contrast of a center stimulus is reduced when it is presented within a higher-contrast surrounding stimulus. Many key aspects of visual perception involve surround suppression, yet the neuromodulatory processes involved remain unclear. Psilocybin is a serotonergic psych...
Psychedelics have recently re-emerged as potential treatments for various psychiatric conditions that impose major public health costs and for which current treatment options have limited efficacy. At the same time, personalized medicine is increasingly being implemented in psychiatry to provide individualized drug dosing recommendations based on genetics. T...
Background Recent studies have intensively explored the potential antidepressant effects of psilocybin. However, important variables such as previous experience, repeated administration, setting and sex remain underexplored. This study describes the acute psilocybin experience and long-term effects in a small sample of healthy individuals. Methods In a doubl...
BACKGROUND: Psychedelic substances reliably induce marked altered states of consciousness (ASC), which may be important for lasting effects and clinical outcomes of psychedelic intervention. Several instruments are available to measure the acute psychedelic experience, of which the Five Dimensional Altered States of Consciousness Questionnaire (5D-ASC) is co...
Intense interest surrounds current research on psychedelics, particularly regarding their potential in treating mental health disorders. Various studies suggest a link between the subjective effects produced by psychedelics and their therapeutic efficacy. Neuroimaging evidence indicates an association of changes in brain functional connectivity with the subj...
Abstract Psychedelic therapy has the potential to become a revolutionary and transdiagnostic mental health treatment, yielding enduring benefits that are often attributed to the experiences that coincide with peak psychedelic effects. However, there may be an underrecognized temporal structure to this process that helps explain why psychedelic and related al...
Psychiatry is in a growth phase in which several psychedelic medicines have entered its arena with great promise. Of these, presently, ketamine is the only medicine that may be legally prescribed. We hypothesize that at subanesthetic doses, ketamine produces a unique spectrum of altered states, ranging from psychoactive to deep ego-dissolving experiences, th...
BACKGROUND: Serotonergic psychedelics, such as psilocybin, alter perceptual and cognitive systems that are functionally integrated with the amygdala. These changes can alter cognition and emotions that are hypothesized to contribute to their therapeutic utility. However, the neural mechanisms of cognitive and subcortical systems altered by psychedelics are n...
Background: Depression is a major global health challenge, affecting over 300 million people worldwide. Current pharmacological and psychotherapeutic interventions have limited efficacy, underscoring the need for novel approaches. Emerging evidence suggests that peak emotional experiences characterized by awe, transcendence, and meaning hold promise for rapi...
Cannabis and classic psychedelics are controlled substances with emerging evidence of efficacy in the treatment of a variety of psychiatric illnesses. Cannabis has largely not been regarded as having psychedelic effects in contemporary literature, despite many examples of historical use along with classic psychedelics to attain altered states of consciousnes...
BACKGROUND: Research with the Psychedelic Experience Questionnaire/Scale (PES) focuses on questions relating to mystical experience (Mystical Experience Questionnaire (MEQ)). The psychometric potential of the non-MEQ items of the PES remains largely unexplored. AIMS: We investigated whether the PES also yields subscales besides the MEQ30 subscales. METHODS: ...
Interest in the use of serotonergic agonists such as psilocybin in treatment-resistant depression (TRD) has grown more quickly than the evidence on which to base a final opinion, as emphasized by McIntyre et al1 in their review. Psilocybin, once metabolized to psilocin, activates 5-HT2A receptors, enhancing GABA function in local circuits in the cortex and i...
Background: Psychedelic drug experiences are shaped by current-moment contextual factors, commonly categorized as internal (set) and external (setting). Potential influences of past environments, however, have received little attention. Aims: To investigate how previous environmental stimuli shaped the experiences of patients receiving ketamine for treatment...
BACKGROUND: Pharmacological and nonpharmacological methods of inducing altered states of consciousness (ASCs) are becoming increasingly relevant in the treatment of psychiatric disorders. While comparisons between them are often drawn, to date no study has directly compared their neural correlates. METHODS: To address this knowledge gap, we directly compared...
The Altered Xperience Project (AXP) is an ongoing research project that takes the form of an open citizen science initiative. Its main goal is to systematically collect and consolidate data on the subjective experiences induced by various consciousness-manipulating techniques (CMTs). These include both psychoactive substances as well as non-pharmacological m...
The Altered Xperience Project (AXP) is an ongoing research project that takes the form of an open citizen science initiative. Its main goal is to systematically collect and consolidate data on the subjective experiences induced by various consciousness-manipulating techniques (CMTs). These include both psychoactive substances as well as non-pharmacological m...
The emerging neuroscientific frontier of brain fingerprinting has recently established that human functional connectomes (FCs) exhibit fingerprint-like idiosyncratic features, which map onto heterogeneously distributed behavioural traits. Here, we harness brain-fingerprinting tools to extract FC features that predict subjective drug experience induced by the...
Psychedelics are a unique class of drug that commonly produce vivid hallucinations as well as profound psychological and mystical experiences. A grouping of interconnected brain regions characterized by increased temporal coherence at rest have been termed the Default Mode Network (DMN). The DMN has been the focus of numerous studies assessing its role in se...
