Background: Psychedelic microdosing—repeated sub-perceptual doses of lysergic acid diethylamide (LSD) or psilocybin—has attracted scientific interest as a potential mood and cognitive intervention. The evidence base remains methodologically heterogeneous and vulnerable to expectancy bias. Methods: We conducted an umbrella review with narrative synthesis following Joanna Briggs Institute...
With growing research on the use of psychedelics to treat mental health conditions, greater attention to the psychosocial procedures accompanying substance administration is warranted. This scoping review aims to categorize psychosocial protocols used in research involving psychedelics as psychiatric treatment according to their purpose, denomination, format, therapeutic orientation,...
Oral S-ketamine (S-KETPO) is being explored as an alternative to intravenous maintenance treatment (S-KETIV) in treatment-resistant depression (TRD). However, the first-pass effect with S-KETPO significantly alters S-ketamine's bioavailability and the systemic exposure of its active metabolites, raising potential safety and efficacy concerns. This study characterized the pharmacodynamic and...
In the past decade, interest in studying psychedelic compounds as potential therapeutic agents has resurged. These studies carefully exclude individuals at risk for developing psychotic symptoms in response to psychedelic use. Given the potential for psychedelics to be established as treatments in psychiatry, it is important to more robustly understand their link with psychosis and...
Ketamine has emerged as a promising rapid-acting treatment for mood disorders and suicidality. Notwithstanding its replicated antidepressant efficacy, ketamine-associated risk for abuse, dependence, and misuse remain. We conducted a systematic review of clinical and preclinical studies from database inception to August 2025, including randomized and observational trials, open-label extensions,...
BACKGROUND: Major depressive disorder is one of the most debilitating psychiatric disorders worldwide. First-line treatments such as selective serotonin reuptake inhibitors have significant limitations, including delayed onset of therapeutic effects and treatment resistance in about 30% of patients. Increasing evidence suggests that acute administration of serotonergic psychedelics, such as...
The therapeutic potential of psychedelics is currently being explored in a range of neuropsychiatric conditions. Nevertheless, their designation as Schedule 1 substances causes substantial regulatory and economic barriers to research. Rigorous human mechanistic studies are required to address the critical knowledge gaps surrounding the mechanisms underlying the putative treatment effects of...
While research on novel therapeutic applications of ketamine is expanding, particularly in controlled settings, there is limited exploration of its consumption related to self-treatment of psychiatric conditions. This study investigated the characteristics of people who use ketamine and psychedelics for self-treatment of psychiatric conditions, providing insight into patterns of use within this...
Ketamine and esketamine ("es/ketamine") treatment protocols have been investigated in patients' samples with treatment-refractory anxiety disorders. We systematically reviewed publications in which es/ketamine was used to treat anxiety symptoms in the context of either Diagnostic and Statistical Manual of Mental Disorders, Fifth Edition (DSM-5) anxiety disorders or treatment-resistant...
The impact of classic psychedelics (5-HT2A receptor agonists) on personality traits has been studied for decades, and it has been hypothesized that the mechanisms underlying these changes are linked to agonism at cortical serotonergic 5-HT2A receptors. However, research results are contradictory. Therefore, the present paper aims to systematically evaluate the effects of psychedelics on...
Despite renewed investigations into classical psychedelic compounds, their pharmacokinetic profiles remain incompletely understood. This systematic review collated data from healthy adult volunteers on the pharmacokinetic properties of lysergic acid diethylamide (LSD), psilocybin, dimethyltryptamine (DMT), mescaline, and 5-methoxy-N,N-dimethyltryptamine (5-MEO-DMT). We identified 32 eligible...
Patients with chronic cluster headache (CCH) suffer from poor sleep, which may impact their brain microstructure and parenchymal clearance of waste products. Psilocybin has shown promise for the treatment of CCH and has been linked to increased neuroplasticity with possible influences on brain microstructure. To investigate the effects of psilocybin on sleep, brain water diffusivity, and...
5-Methoxy-N,N-dimethyltryptamine (5-MeO-DMT), a potent, short-acting psychedelic, induces profound shifts in cognition, affect, and self-awareness. Because language explicitly expresses these domains and voice implicitly conveys them, both may serve as potential 'biomarkers' of behavioural change. This study introduces a novel framework for analysing baseline language and vocal features, pre-...
BACKGROUND: Preliminary evidence examining ibogaine in neuropsychiatric and substance use disorders is accumulating. As patient interest and off-label use grow, clinicians require an understanding of emerging dosing strategies, investigational protocols, and reported adverse effects to appropriately counsel patients and contextualize potential risks and benefits. METHODS: Databases were...
Journal of PsychopharmacologyMay 7, 2026Elahe Rohani, Fatemeh Mohtashami Borzadaran, Marzieh Mowlavi Vardanjani et al.
Background: Ketamine, an N-methyl-D-aspartate (NMDA) receptor antagonist, has gained attention for its rapid antidepressant effects at subanesthetic doses. However, its potential for overdose and cognitive side effects, especially after misuse, remains a concern. The impact of ketamine on inhibitory control, a critical component of executive function, is not well understood. Oxytocin, a...
Serotonergic psychedelics are being investigated in the treatment of various disorders and in the improvement of well-being. Evidence suggests that their subjective effects may play a role in long-term behavioral outcomes. The subjective effects are mediated by 5-HT2A receptor agonism, but the 5-HT1A receptor may also play a role in the subjective effects. This study elucidates the effects of...
Psychedelic-assisted therapy (PAT) has demonstrated substantial efficacy across a range of mental disorders. However, heterogeneity between patients confers differential responsiveness. This systematic review aims to explore factors which may predict therapeutic responses to PAT. A systematic search was performed from inception through to March 2024 and studies that assessed predictors of...
The nature and role of the psychological support provided in psychedelic-assisted treatments for psychiatric disorders are currently the object of debate. How this support is conceptualized-as a vector for therapeutic change or framework for risk minimization-has far-reaching consequences in terms of how these treatments should be regulated, delivered, and studied. To determine whether...
While psychedelics have shown initial promise in the treatment of migraine, experimental studies have relied on small and homogenous samples, which limit the reliability and generalizability of findings. These limitations underscore the complementary value of other research designs that leverage larger and more representative samples. This cross-sectional study included three cohorts of twins...
Existing tools assess psychedelic experiences, but none specifically measure altered processing of traumatic memories-a key mechanism in trauma-focused therapies and psychotherapy in general. The helioscope effect describes how psychedelics like psilocybin and 3,4-methylenedioxymethamphetamine (MDMA) enable revisiting challenging or traumatic experiences while remaining protected from...
Psychedelic drugs are increasingly under investigation as potential therapeutic agents for mental health conditions and are being increasingly used recreationally. Psychedelic use may result in an episode of intense psychological distress, commonly referred to as a "bad trip." Bad trips represent a potentially volatile, erratic, and dangerous situation, which may, in extreme cases, require...
The October 7th, 2023, attack at the Nova rave represents an unprecedented scenario in trauma research: A mass casualty event in which most participants were under the influence of psychedelics. Using a mixed-methods phenomenological design, 45 survivors were interviewed. Participants were categorized by substance use: classic psychedelics (n = 24), empathogens (n = 19), and ketamine (n = 2)....
Previous research suggests that psychedelics may, under certain conditions, decrease authoritarian attitudes, but larger and more rigorously designed studies are needed to confirm these findings. We aimed to examine the effects of psychedelic use on authoritarian attitudes. Using data from three separate studies with different designs and populations, we investigated the relationship between...
Interleukin-6 (IL-6) has been implicated as a potential predictor of ketamine response in treatment-resistant depression (TRD). Esketamine, the S-enantiomer of ketamine, produces rapid antidepressant effects and offers improved safety and intranasal administration. To examine whether baseline IL-6 predicts treatment response to esketamine in individuals with TRD. Fourteen adults with TRD...
Background: Little research investigates the role of rarely used drugs in criminal offending. Moreover, given research suggesting that psychedelics reduce criminal offending, more research is needed to further document connections between psychedelics and crime. Aim: This study examines the role of rarely used drugs in criminal behavior and extends previous research on psychedelics by...