BACKGROUND: N,N-dimethyltryptamine is a short-acting psychedelic tryptamine found naturally in many plants and animals. Few studies to date have addressed the neural and psychological effects of N,N-dimethyltryptamine alone, either administered intravenously or inhaled in freebase form, and none have been conducted in natural settings. AIMS: Our primary aim was to study the acute effects of...
Sub-anesthetic ketamine administration may be helpful for substance use disorders. Converging evidence suggests that the efficacy of ketamine for certain conditions may implicate a subset of its psychoactive effects. The aim of this analysis is to evaluate whether the mystical-type effects of ketamine are critical for clinical efficacy in alcohol-dependent individuals. In this secondary...
Ketamine has rapid anxiolytic effects in treatment-resistant obsessive compulsive, post-traumatic stress, generalised anxiety and social anxiety disorders. This study aimed to assess changes following acute and maintenance ketamine therapy on the Fear Questionnaire (FQ) subscales and the Spielberger State Anxiety Inventory (SSAI). This secondary analysis used data from a mixed open-label and...
Background: Several measures have been developed to examine acute psychedelic effects (e.g. mystical-type and challenging experiences), but no measure assesses acute psychologically insightful experiences that may occur during psychedelic experiences. Aim: The purpose of this study was to develop and examine the psychometric properties of the Psychological Insight Questionnaire. Method: A...
BACKGROUND: While the acute effects of cannabis are relatively benign for most users, some individuals experience significant adverse effects. This study aimed to identify whether variation in schizotypal personality traits and frequency of cannabis use influence the acute effects of delta-9-tetrahydrocannabinol (THC). METHODS: Individual participant data from four double-blind, randomised,...
Rationale: Novel, evidence-based treatments are required for treatment-resistant post-traumatic stress disorder (PTSD). 3,4-Methylenedioxymethamphetamine (MDMA) has beneficially augmented psychotherapy in several small clinical trials. Objective: To review the use of MDMA-assisted psychotherapy in treatment-resistant PTSD. Methods: Systematic searches of four databases were conducted from...
The discovery of the rapid antidepressant effects of the dissociative anaesthetic ketamine, an uncompetitive N-Methyl-D-Aspartate receptor antagonist, is arguably the most important breakthrough in depression research in the last 50 years. Ketamine remains an off-label treatment for treatment-resistant depression with factors that limit widespread use including its dissociative effects and...
Background: Psilocybin is a serotonergic psychedelic found in “magic mushrooms” with a putative therapeutic potential for treatment-resistant depression, anxiety, obsessive-compulsive disorder, and addiction. In rodents, psilocybin acutely induces plasticity-related immediate early genes in cortical tissue; however, studies into the effects on subcortical regions, of different doses, and the...
Background: Individuals meeting criteria for treatment-resistant depression (TRD) are differentially affected by high levels of anxiety symptoms. Aims: There is a need to identify the efficacy of novel rapid-onset treatments in adults with mood disorders and comorbid anxious-distress. Methods: This study included patients with treatment-resistant major depressive disorder (MDD) or bipolar...
Background: Lysergic acid diethylamide (LSD) and 3,4-methylenedioxymethamphetamine (MDMA) were used in psychotherapy in the 1960s–1980s, and are currently being re-investigated as treatments for several psychiatric disorders. In Switzerland, limited medical use of these substances is possible in patients not responding to other treatments (compassionate use). Methods: This study aimed to...
Background: Psilocybin is a serotonergic psychedelic with psychoactive effects mediated by serotonin 2A receptor (5-HT2AR) activation. It produces an acute psychedelic altered state of consciousness with a unique phenomenology that can be temporally characterized by three intensity phases: onset of psychoactive effect, a peak plateau and return to normal consciousness. Aims: We evaluated...
Background: Microdosing psychedelics is the practice of taking small, sub-hallucinogenic doses of lysergic acid diethylamide or psilocybin-containing mushrooms. Despite its surging popularity, little is known about the specific intentions to start microdosing and the effects of this practice. Aims: First, we aimed to replicate previous findings regarding the subjective benefits and challenges...
The last two decades have seen a revival of interest in the entactogen 3,4-methylenedioxy-N-methylamphetamine (MDMA) as an adjunct to psychotherapy, particularly for the treatment of post-traumatic stress disorder. While clinical results are highly promising, and MDMA is expected to be approved as a treatment in the near future, it is currently the only compound in its class of action that is...
Experiences of having an encounter with seemingly autonomous entities are sometimes reported after inhaling N,N-dimethyltryptamine. The study characterized the subjective phenomena, interpretation, and persisting changes that people attribute to N,N-dimethyltryptamine-occasioned entity encounter experiences. Two thousand, five hundred and sixty-one individuals (mean age 32 years; 77% male)...
Background: Lysergic acid diethylamide (LSD) is an ergot alkaloid derivative with psychedelic properties that has been implicated in the management of persistent pain. Clinical studies in the 1960s and 1970s have demonstrated profound analgesic effects of full doses of LSD in terminally ill patients, but this line of research evaporated after LSD was scheduled worldwide. Aim: The present...
BACKGROUND: Cannabidiol has potential therapeutic benefits for people with psychiatric disorders characterised by reward function impairment. There is existing evidence that cannabidiol may influence some aspects of reward processing. However, it is unknown whether cannabidiol acutely affects brain function underpinning reward anticipation and feedback. HYPOTHESES: We predicted that cannabidiol...
Background: Data on actual harm of magic mushrooms suggest that toxicity and abuse potential is low, however, their legal status suggests otherwise. We aimed to gauge perception of harm of magic mushrooms in both users and mushroom-naïve participants. We also aimed to observe differences in expectations of effects between users and mushroom-naïve participants, and whether motivations for use...
Background: Ayahuasca is a traditional Amazon brew and its potential antidepressant properties have recently been explored in scientific settings. We conducted a double-blind placebo-controlled trial of ayahuasca with treatment-resistant depression patients ( n = 28) and healthy controls ( n = 45). Aims: We are evaluating the blood inflammatory biomarkers: C-reactive protein and interleukin 6,...
Background: Recently, the recreational use of substituted phenethylamines has grown rapidly. Among these are 2-(3,5-dimethoxy-4-((2-methylallyl)oxy)phenyl)ethanamine (MAL) and 2-(2,5-dimethoxy-4-methylphenyl)-2-methoxyethan-1-amine (BOD). However, studies characterizing their abuse potential are still lacking. Aim: The purpose of this study was to investigate the abuse potential of MAL and BOD....
Background: Synthetic cathinone derivatives are used as alternatives both for stimulant drugs such as cocaine and methamphetamine and for club drugs such as 3,4-methylenedioxymethamphetamine (MDMA), but little is known about their MDMA-like subjective effects. Methods In order to determine their similarity to MDMA, the discriminative stimulus effects of 10 pyrrolidinyl cathinones...
Rodent behavioural assays are widely used to delineate the mechanisms of psychiatric disorders and predict the efficacy of drug candidates. Conventional behavioural paradigms are restricted to short time windows and involve transferring animals from the homecage to unfamiliar apparatus which induces stress. Additionally, factors including environmental perturbations, handling and the presence...
BACKGROUND: 3,4-Methylenedioxymethamphetamine (MDMA) is being actively researched as an adjunct to psychotherapy. It may be beneficial to trust, empathy and cooperative behaviour due to its acute prosocial effects. AIM: To test (a) the acute effects of MDMA on measures of empathy, trust and cooperative behaviour, and (b) subacute changes in mood three days after MDMA administration. METHODS: =7...
New psychoactive substances (NPS) pose a public health threat. Many studies have tried to identify the reasons of NPS use; however, none of them have so far used any standardised measures. The aim of this study was (i) to develop and cross-culturally validate the New Psychoactive Substance Use Motives Measure (NPSMM) and (ii) to compare motives of NPS use across countries and user types. Three...
Background: Psychedelic drugs have shown an efficacy in some psychiatric disorders and have an original mechanism of action with a 5-HT 2A agonism. Aim: The aim of this meta-analysis was to assess by a quantitative analysis the putative efficacy of psychedelic drugs on depressive symptoms and to investigate the kinetic of this efficacy. Methods: We searched the MEDLINE and PsycINFO databases...
Background: We previously reported that ketamine has anxiolytic effects in patients with treatment-resistant generalized anxiety and social anxiety disorders. Aims: The purpose of this study was to replicate our earlier report about ketamine‘s anxiolytic activity, using a more robust study design. Methods: This was a double-blind, psychoactive-controlled ascending dose study in 12 patients with...