Molecular Psychiatry
August 4, 2026
Kim P. C. Kuypers, Natasha L. Mason, Aurelie Carlier et al.
Women experience a disproportionate burden of affective and stress-related disorders, with symptom variability shaped by endocrine transitions across the menstrual cycle, pregnancy, postpartum, and menopause. Although psychedelic-assisted therapies are increasingly investigated for these conditions, hormonal state represents a largely unaccounted determinant of variability in exposure,...
Frontiers in Neuroscience
August 3, 2026
Kim P. C. Kuypers
Psychedelic-assisted therapy has shown rapid and durable benefits across multiple psychiatric conditions, yet the mechanisms underlying these effects remain incompletely understood. Full-dose psychedelic sessions simultaneously engage serotonergic neurochemistry, high-intensity subjective experience, and autonomic-interoceptive physiology, making it difficult to determine which components are...
bioRxiv (Cold Spring Harbor Laboratory)
July 13, 2026
Natasha L. Mason, Eline Chm Haijen-Bongers, Kim P. C. Kuypers et al.
Serotonergic psychedelics are advancing as psychiatric treatments, yet acute responses vary between individuals and the contribution of sex, a fundamental biological variable, remains largely unexamined. We pooled two double-blind, placebo-controlled studies in healthy volunteers (N = 72; 31 male, 41 female) comparing psilocybin 15 mg, 2C-B 20 mg, and LSD 50 μg. Linear mixed models tested sex...
Journal of Psychedelic Studies
July 3, 2026
Henry J. Whitfield, Jan Schepers, Natasha L. Mason et al.
Abstract Despite growing interest in psychedelic-assisted psychotherapy, research investigating the psychotherapeutic components is lacking. This leaves unanswered questions regarding the psychotherapy's necessity and form. This observational study addresses this gap by measuring the outcomes of a psilocybin truffle retreat, followed by the outcomes of two psychotherapy interventions that...
Molecular Psychiatry
April 8, 2026
Johannes G. Ramaekers, Kim P. C. Kuypers, Franz X. Vollenweider
1 citation
MDMA's history spans military experimentation, recreational use, and clinical trials for PTSD treatment, reflecting both promise and controversy. While studies in heavy users suggested possible neurotoxicity, evidence remains inconclusive. Clinical trials show that one to three sessions of MDMA-assisted psychotherapy can alleviate PTSD symptoms, yet regulators have criticized inadequate...
Nature Medicine
April 1, 2026
Manesh Girn, Manoj K. Doss, Leor Roseman et al.
8 citations
Psychedelic drugs are re-emerging as promising scientific and clinical tools. However, despite a rapidly expanding literature on their therapeutic value, the neural mechanisms underlying psychedelic effects remain unclear. Resting-state functional magnetic resonance imaging studies of acute psychedelic effects, conducted independently by several research groups, have so far yielded fragmented...
Psychopharmacology
October 11, 2025
Michelle St Pierre, Elena Argento, Jordyn Cates et al.
Repeated self-administration of small doses of psychedelics, known as microdosing, has been associated with perceived improvements in psychological functioning. However, few studies have examined effects at the daily level. Drawing on data from a naturalistic, prospective, international survey of adults who microdose (N = 1435), we assessed self-reported within-person changes between...
Br J Pain
September 4, 2025
Mauro Cavarra, Nadia R. P. W. Hutten, Jan Schepers et al.
A randomised placebo-controlled study of the effects of lysergic acid diethylamide microdosing (15 μg) on pain perception in healthy volunteers.
Journal of Psychedelic Studies
September 4, 2025
Giordano Novak Rossi, Rishma S. I. Khubsing, Eline Haijen et al.
Abstract Background and aims Research on classical psychedelics like ayahuasca is increasingly focused on treating mental disorders and enhancing well-being. Ayahuasca has shown promise in improving cognitive flexibility, emotion regulation, and sleep, though findings are mixed and further research is needed. This study tracked participants over three months, assessing cognitive flexibility,...
Current Opinion in Psychology
August 6, 2025
Iva Totomanova, Eline Haijen, Petra P M Hurks et al.
5 citations
Microdosing psychedelics, the regular use of low doses of LSD or psilocybin, have attracted growing public and scientific interest. This review synthesizes findings from 57 human studies on psychological and physiological outcomes in clinical and non-clinical populations. Reported benefits include improved mood, enhanced cognition, social functioning, and mental health, although findings are...
JAMA Psychiatry
June 1, 2025
Lorenz Mueller, Joyce Santos de Jesus, Yasmin Schmid et al.
14 citations
Microdosing psychedelics, including lysergic acid diethylamide (LSD), has gained attention for its potential benefits in several psychiatric disorders, including attention-deficit/hyperactivity disorder (ADHD). However, LSD's efficacy in reducing ADHD symptoms remains unknown. To determine the safety and efficacy of repeated low doses of LSD in reducing ADHD symptoms compared with placebo. This...
Neuropsychopharmacology : official publication of the American College of Neuropsychopharmacology
June 1, 2025
Johannes G. Ramaekers, Johannes T. Reckweg, Natasha L. Mason et al.
8 citations
3-Methylmethcathinone (3-MMC) is a designer drug that belongs to the group of synthetic cathinones. The compound has been scheduled in many jurisdictions because of public health concerns associated with excessive use. To date, there are no clinical studies that have evaluated the risk profile of 3-MMC in the recreational range of low to moderate doses. The current, first-in-human study (N =...
European Psychiatry
April 1, 2025
Kim P. C. Kuypers
Abstract Several years ago, the first studies were conducted in which the effects of psychedelics in low doses were tested in healthy participants. These studies focused mainly on the acute effects of LSD. Questions that remained unanswered were whether low doses have lasting effects, as well as whether they can reduce symptoms of ADHD. To answer these questions, we conducted two studies,...
European Psychiatry
2025
Marianne Destoop, Pavel Mohr, Florence Butlen-Ducuing et al.
7 citations
Abstract Background Recent years show an exponential increased interest (“renaissance”) in the use of psychedelics for the treatment of mental disorders and broader. Some of these treatments, such as psilocybin for depression, are in the process of formal regulation by regulatory bodies in the US (FDA) and Europe (EMA), and as such on the brink of real-world implementation. In the slipstream of...
International review of neurobiology
2025
Iva Totomanova, Eline Haijen, Petra P M Hurks et al.
Clinical trials using full doses of psychedelics have provided preliminary evidence supporting their safety and efficacy in treating a variety of physical and psychological conditions. Anecdotal reports indicate that even very small amounts of these substances may provide therapeutic benefits, though robust clinical studies are still needed. This chapter reviews the current experimental studies...
European neuropsychopharmacology : the journal of the European College of Neuropsychopharmacology
August 1, 2024
Zeus Tipado, Kim P. C. Kuypers, Bettina Sorger et al.
5 citations
Psychedelics like LSD (Lysergic acid diethylamide) and psilocybin are known to modulate perceptual modalities due to the activation of mostly serotonin receptors in specific cortical (e.g., visual cortex) and subcortical (e.g., thalamus) regions of the brain. In the visual domain, these psychedelic modulations often result in peculiar disturbances of viewed objects and light and sometimes even...
Translational Psychiatry
July 15, 2024
Nadia R. P. W. Hutten, Conny W E M Quaedflieg, Natasha L. Mason et al.
16 citations
The repeated use of small doses of psychedelics (also referred to as "microdosing") to facilitate benefits in mental health, cognition, and mood is a trending practice. Placebo-controlled studies however have largely failed to demonstrate strong benefits, possibly because of large inter-individual response variability. The current study tested the hypothesis that effects of low doses of LSD on...
Psychoactives
March 31, 2024
Rishma S. I. Khubsing, Martin van Leerdam, Eline Haijen et al.
3 citations
Background: In recent years, there has been a growing interest in the therapeutic potential of classical psychedelics like ayahuasca for mental health improvement. Naturalistic studies at ayahuasca retreats have shown (short-term) improvements in mental well-being but understanding the psychological mechanisms is crucial. We are interested in psychological processes such as resilience,...
Progress in neuro-psychopharmacology & biological psychiatry
January 10, 2024
Mesud Sarmanlu, Kim P. C. Kuypers, Patrick Vizeli et al.
17 citations
The application of MDMA in conjunction with psychotherapy has in recent years seen a resurgence of clinical, scientific, and public interest in the treatment of posttraumatic stress disorder (PTSD). Clinical trials have shown promising safety and efficacy, but the mechanisms underlying this treatment form remain largely unestablished. This article explores recent preclinical and clinical...
European Psychiatry
2024
Eline Haijen, Petra P M Hurks, Kim P. C. Kuypers
10 citations
Abstract Adults with attention-deficit hyperactivity disorder (ADHD) often struggle with emotion regulation (ER), impacting their empathic skills and relationships. ADHD medication might not be as effective for ER issues as for ADHD symptoms. Microdosing (MD) psychedelics has shown promise for ADHD treatment and previous studies reported social-emotional benefits. Two online prospective studies...
Frontiers in Psychiatry
October 16, 2023
Eline Haijen, Petra P M Hurks, Kim P. C. Kuypers
6 citations
Background Microdosing (MD), repeatedly taking psychedelics in small, non-hallucinogenic amounts, has been practiced by individuals to relieve attention deficit hyperactivity disorder (ADHD) symptoms. Generally, adults diagnosed with ADHD have lower levels of mindfulness and differ in personality structure from non-ADHD adults. How MD affects mindfulness and personality in adults with ADHD...
Brain Behavior and Immunity
September 7, 2023
Natasha L. Mason, Attila Szabo, Kim P. C. Kuypers et al.
83 citations
Patients characterized by stress-related disorders such as depression display elevated circulating concentrations of pro-inflammatory cytokines and a hyperactive HPA axis. Psychedelics are demonstrating promising results in treatment of such disorders, however the mechanisms of their therapeutic effects are still unknown. To date the evidence of acute and persisting effects of psychedelics on...
European Journal of Pain
August 20, 2023
Mauro Cavarra, Amanda Feilding, Pamela Kryskow et al.
28 citations
Abstract Background Chronic pain is a major cause of suffering and disability and is often associated with psychiatric complications. Current treatments carry the risk of severe side effects and may lead to limited or no relief at all in a relevant portion of this patient population. Preliminary evidence suggests that classical psychedelics (e.g. LSD and psilocybin) may have analgesic effects...
Tijdschrift voor Geneeskunde
July 24, 2023
E. Geleyn, Kim P. C. Kuypers, Mathieu Seynaeve et al.
Classic psychedelics: safety, side effects and medication interactions Given the growing scientific and social interest in the use of classic psychedelics for psychiatric disorders, physicians are increasingly confronted with patients resorting to these drugs. To this date, treatment with classic psychedelics within a medical framework is non-existent. Patients could seek such a treatment...
Clinical Pharmacology & Therapeutics
May 30, 2023
Pablo Mallaroni, Riccardo Paci, Sabrina Ritscher et al.
34 citations
2,5‐dimethoxy‐4‐bromophenethylamine (2C‐B) is a hallucinogenic phenethylamine derived from mescaline. Observational and preclinical data have suggested it to be capable of producing both subjective and emotional effects on par with other classical psychedelics and entactogens. Whereas it is the most prevalently used novel serotonergic hallucinogen to date, it's acute effects and distinctions...