The use of psychedelic substances at sub-sensorium 'microdoses', has gained popular academic interest for reported positive effects on wellness and cognition. The present study describes microdosing practices, motivations and mental health among a sample of self-selected microdosers (n = 4050) and non-microdosers (n = 4653) via a mobile application. Psilocyb...
RationaleClassical psychedelics, including psilocybin and lysergic acid diethylamide (LSD), are under investigation as potential therapeutic agents in psychiatry. Whereas most studies utilize relatively high doses, there are also reports of beneficial effects of "microdosing," or repeated use of very low doses of these drugs. The behavioral and neural effect...
BackgroundPsilocybin is a psychedelic drug that has shown lasting positive effects on clinical symptoms and self-reported well-being following a single dose. There has been little research into the long-term effects of psilocybin on brain connectivity in humans.AimEvaluate changes in resting-state functional connectivity (RSFC) at 1 week and 3 months after o...
BackgroundThe recognition of emotions in facial expressions (REFE) is a core aspect of social cognition. Previous studies with the serotonergic hallucinogens lysergic acid diethylamide and psilocybin showed that these drugs reduced the recognition of negative (fear) faces in healthy volunteers. This trial assessed the acute and prolonged effects of a single ...
BackgroundPsilocybin may have antidepressant properties, but direct comparisons between psilocybin and established treatments for depression are lacking.MethodsIn a phase 2, double-blind, randomized, controlled trial involving patients with long-standing, moderate-to-severe major depressive disorder, we compared psilocybin with escitalopram, a selective sero...
BackgroundDespite tetrahydrocannabinol (THC)'s reputation for creating dramatic effects at high doses, empirical work rarely addresses cannabis's impact on subjective responses common to the tryptamine psychedelics. We focused on these effects because they have preceded and covaried with the therapeutic impact of psilocybin in previous work.AimsThe current s...
IntroductionCannabidiol (CBD) is purportedly a promising therapeutic agent to provide relief for a variety of medical conditions with mild or no psychoactive effects. However, little is known about young adults who use cannabis and CBD-dominant products, and associations between CBD use and other drug use.MethodsYoung adults (aged 24-32) who currently used c...
Tryptamines are hallucinogenic substances many of which have appeared recently as novel psychoactive substances (NPS). Herein, we describe the establishment of a rapid UHPLC-MS/MS quantitative method for the targeted screening of 16 tryptamines of abuse in hair. Twenty milligram pieces of hair were pulverized below 4 °C in 0.5 mL of deionized water containin...
Bonny Method of Guided Imagery and Music emerged following discontinuation of psychedelic therapy research in the early 1970s, but psychedelic therapy research has since revived. Music remains a vital component. This study examined participants' experiences of music in psychedelic therapy research. A rapid review of qualitative and quantitative journal artic...
RationaleIs it possible to have a psychedelic experience from a placebo alone? Most psychedelic studies find few effects in the placebo control group, yet these effects may have been obscured by the study design, setting, or analysis decisions.ObjectiveWe examined individual variation in placebo effects in a naturalistic environment resembling a typical psyc...
BackgroundLysergic acid diethylamide (LSD) and psilocybin are serotonergic hallucinogens that are used primarily for recreational abuse. Small studies evaluated the efficacy of LSD and psilocybin for several psychiatric conditions. There are limited safety or toxicity data for either of these substances, especially in large populations.MethodsThis was a retr...
ObjectivesClassic psychedelics (serotonin 2A receptor agonists) and dissociative hallucinogens (NMDA receptor antagonists), though differing in pharmacology, may share neuropsychological effects. These drugs, however, have undergone limited direct comparison. This report presents data from a double-blind, placebo-controlled within-subjects study comparing th...
AimThe aim of the current study was to investigate the relationship between escalating higher doses of psilocybin and the potential psilocybin occasioned positive subjective effects.MethodsHealthy participants ( n=12) were given three escalating doses of oral psilocybin (0.3 mg/kg; 0.45 mg/kg; 0.6 mg/kg) or (18.8-36.6 mg; 27.1-54.0 mg; 36.3-59.2 mg) a minimu...
Disruptions in social decision-making are becoming evident in many psychiatric conditions. These are studied using paradigms investigating the psychological mechanisms underlying interpersonal interactions, such as the Ultimatum Game (UG). Rejection behaviour in the UG represents altruistic punishment - the costly punishment of norm violators - but the mecha...
BackgroundRecent evidence suggests that psychedelic use predicts reduced perpetration of intimate partner violence among men involved in the criminal justice system. However, the extent to which this association generalizes to community samples has not been examined, and potential mechanisms underlying this association have not been directly explored.AimsThe...
Recent studies suggest that the antidepressant effects of the psychedelic 5-HT2A receptor agonist psilocybin are mediated through its modulatory properties on prefrontal and limbic brain regions including the amygdala. To further investigate the effects of psilocybin on emotion processing networks, we studied for the first-time psilocybin's acute effects on ...
IntroductionPsilocybin is a psychedelic tryptamine that has shown promise in recent clinical trials for the treatment of depression and substance use disorders. This open-label study of the pharmacokinetics of psilocybin was performed to describe the pharmacokinetics and safety profile of psilocybin in sequential, escalating oral doses of 0.3, 0.45, and 0.6 ...
RationaleAlthough psilocybin and dextromethorphan (DXM) are hallucinogens, they have different receptor mechanisms of action and have not been directly compared.ObjectiveThis study compared subjective, behavioral, and physiological effects of psilocybin and dextromethorphan under conditions that minimized expectancy effects.MethodsSingle, acute oral doses of...
RationaleDepressed patients robustly exhibit affective biases in emotional processing which are altered by SSRIs and predict clinical outcome.ObjectivesThe objective of this study is to investigate whether psilocybin, recently shown to rapidly improve mood in treatment-resistant depression (TRD), alters patients' emotional processing biases.MethodsSeventeen ...
Criminal behavior exacts a large toll on society and is resistant to intervention. Some evidence suggests classic psychedelics may inhibit criminal behavior, but the extent of these effects has not been comprehensively explored. In this study, we tested the relationships of classic psychedelic use and psilocybin use per se with criminal behavior among over 4...
