Journal of psychopharmacology (Oxford, England)
September 7, 2026
Torsten Passie, Michiel van Elk
Common wisdom in the psychedelic literature suggests that early controlled trials of psychedelic therapy were methodologically flawed. In this review we challenge this view and discuss 11 controlled studies that were conducted in the United States and Canada between 1965 and 1977 to evaluate psychedelic (peak) therapy for individuals suffering from alcohol and opioid use disorder and...
Open MIND
July 1, 2026
Michiel van Elk
This project investigates how the context of a live concert — including prior expectations, personality, and acute psychoactive substance use — shapes intense emotional and altered-state responses to music, specifically feelings of awe and wonder, mystical-type experiences, and aesthetic chills. The study is part of an ongoing programme of research at the Leiden University PRSM Lab into peak...
Psychedelics
June 28, 2026
Joost J. Breeksema, Ulf Bremberg, Jens H van Dalfsen et al.
The research, understanding, and implementation of psychedelic therapies is characterised by a layered complexity that arises from the dynamic interactions between pharmacological and extra-pharmacological factors, and the embeddedness of psychedelics within broader societal, legal, and regulatory systems ill-equipped to accommodate them. This complexity is compounded by an epistemic...
Philosophical Psychology
April 27, 2026
Michiel van Elk
Scholars of religion have had a long-standing interest in the study of mystical experiences (Schmidt, 2003), dating back to the work of William James (James, 1902). James listed ineffability, noeti...
Philosophical Psychology
November 30, 2025
Julian Kiverstein, Hüseyin Beyköylü, Michiel van Elk
3 citations
Psychedelic research has shown that the effects of serotonergic substances, such as psilocybin and LSD, are strongly influenced by the interaction of substance, set, and setting. Mystical-type experiences, often induced by psychedelics, are not solely driven by pharmacological mechanisms but emerge from a dynamic interplay between the psychological state (set), external environment (setting),...
Sci Rep
November 25, 2025
Laura C. Carvalho, Jorge Encantado, Michiel van Elk et al.
In addition to evidence supporting the use of psychedelics in treating alcohol and tobacco misuse, emerging research suggests that psychedelic experiences may also facilitate beneficial changes in other health behaviors, such as diet, exercise, and meditation. This retrospective, survey-based study explored perceived health behavior changes following psychedelic experiences, from the...
Open Science Framework
November 6, 2025
Michiel van Elk
We investigate how the dose of psilocybin truffles and participant characteristics (trait absorption and expectations) influence subjective experiences and neurophysiological outcomes in a naturalistic field setting.The aim is to replicate observed effects of psilocybin from lab-based and clinical studies in a field / naturalistic setting.
Neuropharmacology
November 2, 2025
Luisa Prochazkova, Josephine Marschall, Michiel van Elk et al.
2 citations
BackgroundTaking very small doses of psychedelics (LSD, truffles) over an extended period became prevalent in Western societies for its alleged cognitive benefit, including enhanced creativity. However, in the absence of robust, double-blind-controlled quantitative studies, such claims remain anecdotal.MethodsHere we present results from 3 double-blind placebo-controlled longitudinal trials...
Journal of Anomalous Experience and Cognition
October 30, 2025
Anastasia Ruban, Michiel van Elk
Return to the Real describes how culturally prevalent narratives shape psychedelic experience. Building on Ten Berge’s two-part analysis, our commentary argues that psychedelic effects are best understood within cultural feedback loops linking cultural set and setting, individual expectations, experience, and its articulation back into culture. On this view, psychedelics operate primarily as...
Journal of Psychoactive Drugs
June 23, 2025
Annika Wirsching, Erwin Krediet, Martijn H B Koolen et al.
4 citations
Psychedelic-assisted psychotherapy (PAP) constitutes a novel treatment paradigm in mental health care practice that is currently being evaluated for its clinical efficacy and safety. Insight into the attitudes of clinicians toward PAP remains crucial for its successful integration into mental health care. This cross-sectional survey explores the attitudes of Dutch mental health care...
Psychiatr Res Clin Pract
February 11, 2025
Jules Evans, Marc Aixalà, Brian T Anderson et al.
18 citations
Objective: This article outlines recommendations from 30 psychedelic researchers on how to create a better psychedelic safety net. Methods: A survey of 30 psychedelic researchers asked them to identify key critical research gaps around psychedelic harm and safety. Results: The critical research gaps identified by the authors included defining the main types of psychedelic harm, the predictors...
The Oxford Handbook of Psychedelic, Religious, Spiritual, and Mystical Experiences
November 19, 2024
Géraldine Carranante, Michiel van Elk
Abstract Progress in the scientific study of altered states of consciousness (ASCs) has been hindered by methodological and conceptual problems. At a methodological level there is a lack of agreement on the scales and instruments used to measure and categorize ASCs. At a conceptual level, existing typologies (such as trigger-based, phenomenology-based, attribution-based, neurobiological, and...
Consciousness and Cognition
August 1, 2024
Piotr Szymanek, Marek Homan, Michiel van Elk et al.
The phenomenon of "hearing voices" can be found not only in psychotic disorders, but also in the general population, with individuals across cultures reporting auditory perceptions of supernatural beings. In our preregistered study, we investigated a possible mechanism of such experiences, grounded in the predictive processing model of agency detection. We predicted that in a signal detection...
Psychoactives
April 16, 2024
Daniel Meling, Rebecca Ehrenkranz, Sandeep M. Nayak et al.
26 citations
Rationale: Psychedelic research re-emerged from a period of suppression into the so-called psychedelic renaissance. In parallel, most media reporting has shifted from the overstatement of the risks of psychedelics to overly positive hype. As the empirical evidence is more equivocal than frequently portrayed, the conclusions about the effectiveness of psychedelics should be considered...
March 10, 2023
Michiel van Elk, Eiko I. Fried
30 citations
preprint
Research in the last decade has expressed considerable optimism about the clinical potential of psychedelics for the treatment of mental disorders. This optimism is reflected in a considerable increase in research papers, investments by pharmaceutical companies, patents, media coverage, as well as political and legislative changes. However, psychedelic science is facing serious challenges that...
Therapeutic Advances in Psychopharmacology
2023
Michiel van Elk, Eiko I. Fried
126 citations
Research in the last decade has expressed considerable optimism about the clinical potential of psychedelics for the treatment of mental disorders. This optimism is reflected in an increase in research papers, investments by pharmaceutical companies, patents, media coverage, as well as political and legislative changes. However, psychedelic science is facing serious challenges that threaten the...
Neuroscience & Biobehavioral Reviews
September 1, 2022
Michiel van Elk, David Bryce Yaden
214 citations
This paper provides a critical review of several possible mechanisms at different levels of analysis underlying the effects and therapeutic potential of psychedelics. At the (1) biochemical level, psychedelics primarily affect the 5-HT2A receptor, increase neuroplasticity, offer a critical period for social reward learning, and have anti-inflammatory properties. At the (2) neural level,...
Journal of Psychoactive Drugs
May 28, 2022
Maja Kohek, Genís Ona, Michiel van Elk et al.
25 citations
Ayahuasca is a plant decoction in traditional Amazonian medicine. Its ritual use has been internationalized, leading to policy challenges that countries should address. This study evaluates the impact of regular ayahuasca ceremony participation on health by assessing the health status of 377 participants in ayahuasca ceremonies in the Netherlands using validated health indicators. A...
Journal of Psychopharmacology
December 17, 2021
Josephine Marschall, George Fejer, Pascal Lempe et al.
69 citations
Background: Microdoses of psychedelics (i.e. a sub-hallucinogenic dose taken every third day) can reduce symptoms of depression, anxiety and stress according to anecdotal reports and observational studies. Research with medium to high doses of psilocybin points towards potential underlying mechanisms, including the modulation of emotion and interoceptive processing. Aims: In this preregistered...
ACS Pharmacology & Translational Science
July 16, 2021
Joost J. Breeksema, Michiel van Elk
69 citations
In response to a recent call to rid psychedelic science of the concept of mystical experience, we argue that acknowledging the varieties and weirdness of psychedelic experiences should be at the heart of any research program on this topic. We highlight the rich tradition and scientific tools for studying mystical-type experiences, their relevance for understanding the therapeutic effects of...
June 14, 2021
Luisa Prochazkova, Michiel van Elk, Josephine Marschall et al.
4 citations
preprint
Introduction: Microdosing refers to the repetitive administration of tiny doses of psychedelics (LSD, Psilocybin) over an extended period of time. This practice has been linked to alleged cognitive benefits, such as improved mood and creativity, potentiated by targeting serotonergic 5-HT2A receptors and facilitating cognitive flexibility. Nonetheless, in the absence of robust, quantitative and...
May 19, 2021
Evan Lewis-Healey, Ruben Laukkonen, Michiel van Elk
4 citations
preprint
Objective: Recent clinical trials have demonstrated that psilocybin may have strong antidepressant effects, and may be effective in the treatment of depressive disorders when embedded in a psychotherapeutic protocol (psilocybin-assisted psychotherapy; PAP). However, despite promising results, the mechanism(s) that may be responsible for the antidepressant effects of PAP remain contested. Within...
Psychopharmacology
April 30, 2021
Michiel van Elk, George Fejer, Pascal Lempe et al.
53 citations
Abstract There is an increased societal trend to engage in microdosing, in which small sub-hallucinogenic amounts of psychedelics are consumed on a regular basis. Following subjective reports that microdosing enhances the experience of nature and art, in the present study we set out to study the effects of psilocybin microdosing on feelings of awe and art perception. In this preregistered...
Psychopharmacology
September 1, 2020
Valerie van Mulukom, Ruairi E Patterson, Michiel van Elk
61 citations
Recent research has shown that classical serotonergic psychedelic (CSP) drugs may be used to ameliorate certain health issues and disorders. Here we hypothesised that CSP experiences, through their ability to induce awe and ego-dissolution, may result in a reduction of maladaptive narcissistic personality traits, such as a strong sense of entitlement and lack of empathy. Our objective was to...
March 10, 2020
Valerie van Mulukom, Ruairi E Patterson, Michiel van Elk
preprint
RationaleThere has been a recent increase in research showing that classical serotonergic psychedelic (CSP) drugs may be used to ameliorate certain health issues and disorders. Here we hypothesized that CSP experiences, through their ability to induce awe and ego-dissolution, may result in a reduction of maladaptive narcissistic personality traits, such as a strong sense of entitlement and lack...