Med (New York, N.Y.)
August 14, 2026
Felix Müller, Anna M Becker, Christopher Böhlke et al.
In Basel, only a few hundred meters from where LSD was first synthesized, we tested LSD-assisted therapy for major depression in a randomized trial comparing two high doses with two low doses, each paired with supportive psychotherapy. This Backstory reflects on treating patients, long dosing days, and what remains uncertain.
Translational Psychiatry
June 4, 2026
Mélusine Humbert‐droz, Anna M Becker, Jan Valenta et al.
3,4-Methylenedioxymethamphetamine (MDMA)-assisted psychotherapy (MDMA-AT) is being investigated as a treatment for several psychiatric disorders, particularly posttraumatic stress disorder. Phase 2 and 3 trials typically administered a first dose of MDMA followed by a second "booster" dose 1.5-2.5 h later, to extend the acute effect duration. However, the risks and benefits of the booster dose...
International Journal of Methods in Psychiatric Research
June 1, 2026
Kurt Stocker, Matthias Hartmann, Frederick S. Barrett et al.
For English, the validated part of Psychedelic Experience Scale (PES48) is a four-factor structure called the Mystical Experience Questionnaire (MEQ30). The other validated part of the PES48 consists of four more factors: two more mystical factors (paradoxicality and connectedness, which together with the MEQ30 form the MEQ40), and two more non-mystical factors (visual experience and...
Cell Reports Medicine
May 7, 2026
Mihai Avram, Aurore Menegaux, Felix Müller et al.
1 citation
The clinical trial NCT03866252 investigates the antidepressant effects of lysergic acid diethylamide (LSD) in 61 patients with major depressive disorder (MDD) randomized to low-dose LSD (LD-LSD; 2 × 25 μg) or moderate-to-high-dose LSD (HD-LSD; 100 μg followed by 200 μg) 4 weeks apart. Although the trial reports positive clinical outcomes, underlying mechanisms remain unclear. Here, we test...
Repository for Publications and Research Data (ETH Zurich)
April 30, 2026
Kurt Stocker, Matthias Hartmann, Frederick S. Barrett et al.
Objectives: For English, the validated part of Psychedelic Experience Scale (PES48) is a four-factor structure called the Mystical Experience Questionnaire (MEQ30). The other validated part of the PES48 consists of four more factors: two more mystical factors (paradoxicality and connectedness, which together with the MEQ30 form the MEQ40), and two more non-mystical factors (visual experience...
Religion Brain & Behavior
March 31, 2026
Kurt Stocker, Matthias Hartmann, Frederick S. Barrett et al.
Mystical dynamics—the notion that mystical oneness may unfold involving ego disintegration, renewal, and luminous light—has been discussed anecdotally by psychedelic researchers and therapists but has not yet been empirically examined in controlled settings. This study investigated the occurrence and dose-dependency of mystical dynamics in healthy participants after administration of...
medRxiv
January 16, 2026
Kristian Larsen, Patrick M. Fisher, Drummond E. Mcculloch et al.
1 citation
Classical psychedelics have regained interest for their potential to treat psychiatric and neurological disorders, and explore neural mechanisms supporting perception, cognition, and mood. Acute psychedelic effects have been linked to increases in brain complexity and entropy, but it is unclear if these changes are specific to psychedelics or reflect more general psychoactive effects. Here, we...
Repository for Publications and Research Data (ETH Zurich)
2026
Kurt Stocker, Matthias Hartmann, Frederick S. Barrett et al.
Mystical dynamics-the notion that mystical oneness may unfold involving ego disintegration, renewal, and luminous light-has been discussed anecdotally by psychedelic researchers and therapists but has not yet been empirically examined in controlled settings. This study investigated the occurrence and dose-dependency of mystical dynamics in healthy participants after administration of...
Journal of psychopharmacology (Oxford, England)
December 26, 2025
Kurt Stocker, Matthias Hartmann, Yasmin Schmid et al.
5 citations
The Altered States of Consciousness Scale (3/5D-ASC or 11-ASC) is widely used to assess non-ordinary states of consciousness, particularly for psychedelic research. However, its original dimensional model (3D-ASC within 5D-ASC) and later 11-subscale structure (11-ASC) have a hierarchically incompatible higher/lower-order structure. Although the 11-ASC offers superior model fit, the 3D-ASC...
Clinical Pharmacokinetics
July 14, 2025
Lorenz Mueller, Aaron Klaiber, Laura Ley et al.
4 citations
Mescaline is a classic serotonergic psychedelic with a long history of human use. The present study analyzed the pharmacokinetics, pharmacokinetic-pharmacodynamic relationship, and urinary recovery of oral mescaline hydrochloride. Data from 105 single-dose administrations (100-800 mg) in 49 participants from two phase I trials were analyzed with compartmental pharmacokinetics and...
Med (New York, N.Y.)
June 4, 2025
Felix Müller, Hannes Zaczek, Anna M Becker et al.
21 citations
This trial aimed to assess the efficacy of lysergic acid diethylamide (LSD)-assisted therapy in patients with moderate-to-severe major depressive disorder. This was a randomized, parallel, double-blind, low-dose controlled trial (Clinicaltrials.gov: NCT03866252). Patients were randomly assigned in a 1:1 ratio to receive supportive psychotherapy and either 100 μg + 200 μg LSD or 25 μg + 25 μg...
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...
Psychopharmacology
March 26, 2025
Laura Ley, Matthias E. Liechti, Anna M Becker et al.
3 citations
Little is known about motives of healthy volunteers to participate in psychedelic trials and how they appraise their study experience retrospectively. This paper explored reasons why healthy people register for psychedelic trials, factors that they considered to contribute to either positive or negative study experiences, and under which circumstances they would seek a psychedelic experience...
Clinical Pharmacology & Therapeutics
February 28, 2025
Lorenz Mueller, Alen Jelusic, Avram Tolev et al.
15 citations
Psychedelics, such as psilocybin and lysergic acid diethylamide (LSD), are being investigated for the treatment of depressive and anxiety disorders, for which concomitant treatment with selective serotonin reuptake inhibitors (SSRIs) is prevalent. The present study investigated the acute response to single doses of LSD (100 μg) after daily administration of paroxetine (10 mg for 7 days,...
Repository for Publications and Research Data
2025
Kurt Stocker, Matthias Hartmann, Yasmin Schmid et al.
Background: The Altered States of Consciousness Scale (3/5D-ASC or 11-ASC) is widely used to assess non-ordinary states of consciousness, particularly for psychedelic research. However, its original dimensional model (3D-ASC within 5D-ASC) and later 11-subscale structure (11-ASC) have a hierarchically incompatible higher/lower-order structure. Although the 11-ASC offers superior model fit, the...
Neuropsychopharmacology
December 19, 2024
Livio Erne, Severin B Vogt, Lorenz Müller et al.
14 citations
Abstract N,N -dimethyltryptamine (DMT) is a serotonergic psychedelic that is known for its short-lasting effects when administered intravenously. Several studies have investigated the administration of intravenous boluses or combinations of a bolus and a subsequent continuous infusion. However, data on dose-dependent acute effects and pharmacokinetics of continuous DMT infusions are lacking. We...
Translational Psychiatry
September 30, 2024
Aaron Klaiber, Yasmin Schmid, Anna M Becker et al.
27 citations
Classic psychedelics have regained interest in research and therapy. Despite the long tradition of the human use of mescaline, modern data on its dose-dependent acute effects and pharmacokinetics are lacking. Additionally, its mechanism of action has not been investigated in humans. We used a randomized, double-blind, placebo-controlled, crossover design in 16 healthy subjects (8 women) who...
Translational Psychiatry
September 4, 2024
Patrick Vizeli, Erich Studerus, Friederike Holze et al.
15 citations
The pharmacodynamic effects of lysergic acid diethylamide (LSD) are diverse and different in different individuals. Effects of other psychoactive substances have been shown to be critically influenced by non-pharmacological factors such as personality traits and mood states. The aim of this study was to determine pharmacological and psychological predictors of the LSD effects in healthy human...
Neuroscience Applied
2024
Isabelle Straumann, Friederike Holze, Laura Ley et al.
24 citations
Psilocybin is being studied for its therapeutic potential in various mental health disorders, such as depression, anxiety, and addiction. Initial studies suggested that psilocybin is generally safe when used under controlled conditions, but more research is needed to better understand its safety profile. We report safety pharmacology data from a pooled analysis of three randomized crossover...
Neuropsychopharmacology : official publication of the American College of Neuropsychopharmacology
December 1, 2023
Isabelle Straumann, Laura Ley, Friederike Holze et al.
41 citations
There is renewed interest in the use of lysergic acid diethylamide (LSD) in psychiatric research and practice. Although acute subjective effects of LSD are mostly positive, negative subjective effects, including anxiety, may occur. The induction of overall positive acute subjective effects is desired in psychedelic-assisted therapy because positive acute experiences are associated with greater...
Journal of Psychopharmacology
October 31, 2023
Kurt Stocker, Matthias Hartmann, Laura Ley et al.
22 citations
Background: Research with the Psychedelic Experience Questionnaire/Scale (PES) focuses on questions relating to mystical experience (Mystical Experience Questionnaire (MEQ)). The psychometric potential of the non-MEQ items of the PES remains largely unexplored. Aims: We investigated whether the PES also yields subscales besides the MEQ30 subscales. Methods: Data from 239 PES measurements (140...
Neuropsychopharmacology : official publication of the American College of Neuropsychopharmacology
October 1, 2023
Laura Ley, Friederike Holze, Denis Arikci et al.
127 citations
Mescaline, lysergic acid diethylamide (LSD), and psilocybin are classic serotonergic psychedelics. A valid, direct comparison of the effects of these substances is lacking. The main goal of the present study was to investigate potential pharmacological, physiological and phenomenological differences at psychoactive-equivalent doses of mescaline, LSD, and psilocybin. The present study used a...
Translational Psychiatry
May 23, 2023
Severin B Vogt, Laura Ley, Livio Erne et al.
85 citations
N,N-dimethyltryptamine (DMT) is distinct among classic serotonergic psychedelics because of its short-lasting effects when administered intravenously. Despite growing interest in the experimental and therapeutic use of intravenous DMT, data are lacking on its clinical pharmacology. We conducted a double-blind, randomized, placebo-controlled crossover trial in 27 healthy participants to test...
Clinical Pharmacology & Therapeutics
December 12, 2022
Friederike Holze, Urs Duthaler, Anna M Becker et al.
116 citations
Psilocybin is being investigated as a potential treatment for psychiatric and neurological disorders. Only a few studies have evaluated the pharmacokinetics (PKs) of psilocybin and have used body weight‐adjusted dosing. Data on PKs and the PK‐pharmacodynamic (PD) relationship of fixed doses that are commonly used are unavailable. The present study characterized the PKs and PK‐PD relationship of...
The International Journal of Neuropsychopharmacology
November 4, 2022
Aaron Klaiber, Friederike Holze, Ioanna Istampoulouoglou et al.
100 citations
Abstract Background Lysergic acid diethylamide (LSD) is currently being investigated in psychedelic-assisted therapy. LSD has a long duration of acute action of 8–11 hours. It produces its acute psychedelic effects via stimulation of the serotonin 5-hydroxytryptamine-2A (HT2A) receptor. Administration of the 5-HT2A antagonist ketanserin before LSD almost fully blocks the acute subjective...