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Aaron Klaiber

18 papers in the library · 647 citations · publishing 2021-2026

Papers

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Mystical dynamics: renewal, luminous light, and ego disintegration as key features associated with mystical oneness—a psychometric analysis using the PES100 in controlled psychedelic studies

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...

Psychedelics distinctly alter brain entropy and complexity compared to psychostimulants

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...

Mystical dynamics: renewal, luminous light, and ego disintegration as key features associated with mystical oneness-a psychometric analysis using the PES100 in controlled psychedelic studies

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...

The 3D-ASCr scale: A revalidation of the core dimensions of the Altered States of Consciousness Rating Scale 5D(11)-ASC for psychedelic research.

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...

Pharmacokinetics, Pharmacodynamics, and Urinary Recovery of Oral Mescaline Hydrochloride in Healthy Participants.

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...

Safety and Efficacy of Repeated Low-Dose LSD for ADHD Treatment in Adults: A Randomized Clinical Trial.

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...

Motivation and retrospective appraisal of psychedelic study participation: a qualitative study in healthy volunteers.

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...

The 3D-ASCr scale: A revalidation of the core dimensions of the Altered States of Consciousness Rating Scale 5D(11)-ASC for psychedelic research

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...

Acute dose-dependent effects and self-guided titration of continuous N,N-dimethyltryptamine infusions in a double-blind placebo-controlled study in healthy participants

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...

Acute effects of R-MDMA, S-MDMA, and racemic MDMA in a randomized double-blind cross-over trial in healthy participants.

Neuropsychopharmacology : official publication of the American College of Neuropsychopharmacology December 1, 2024 Isabelle Straumann, Isidora Avedisian, Aaron Klaiber et al. 20 citations

Racemic 3,4-methylenedioxymethamphetamine (MDMA) acutely increases mood, feelings of empathy, trust, and closeness to others and is investigated to assist psychotherapy. Preclinical research indicates that S-MDMA releases monoamines and oxytocin more potently than R-MDMA, whereas R-MDMA more potently stimulates serotonin 5-hydroxytryptamine-2A receptors. S-MDMA may have more stimulant...

Safety pharmacology of acute mescaline administration in healthy participants.

British Journal of Clinical Pharmacology November 25, 2024 Aaron Klaiber, Mélusine Humbert‐droz, Laura Ley et al. 6 citations

Psychedelics, including mescaline, may serve as novel treatments for depression and anxiety. However, data is scarce on the safety of mescaline. The present pooled analysis included two double-blind, randomized, placebo-controlled studies with a total of 48 participants and 96 mescaline administrations. Single oral-dose administrations (n = 16/dose) of mescaline at doses of 100-800 mg were...

Acute dose-dependent effects of mescaline in a double-blind placebo-controlled study in healthy subjects.

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...

Acute effects of MDMA and LSD co-administration in a double-blind placebo-controlled study in healthy participants.

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...

Comparative acute effects of mescaline, lysergic acid diethylamide, and psilocybin in a randomized, double-blind, placebo-controlled cross-over study in healthy participants.

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...

Acute effects of intravenous DMT in a randomized placebo-controlled study in healthy participants.

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...

Ketanserin Reverses the Acute Response to LSD in a Randomized, Double-Blind, Placebo-Controlled, Crossover Study in Healthy Participants

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...

Development and validation of an LC-MS/MS method for the quantification of mescaline and major metabolites in human plasma

Journal of Pharmaceutical and Biomedical Analysis August 1, 2022 Jan Thomann, Laura Ley, Aaron Klaiber et al. 23 citations

Mescaline is a psychedelic phenethylamine found in different species of cacti. Currently, mescaline's acute subjective effects and pharmacokinetics are investigated in several modern clinical studies. Therefore, we developed a bioanalytical method for the rapid quantification of mescaline and its metabolites in human plasma. Mescaline and its metabolites 3,4,5-trimethoxyphenylacetic acid...

Acute Effects of Psilocybin After Escitalopram or Placebo Pretreatment in a Randomized, Double‐Blind, Placebo‐Controlled, Crossover Study in Healthy Subjects

Clinical Pharmacology & Therapeutics November 7, 2021 Anna M Becker, Friederike Holze, Tanja Grandinetti et al. 177 citations

The psychedelic psilocybin is being investigated for the treatment of depression and anxiety. Unclear is whether antidepressant treatments interact with psilocybin. The present study used a double‐blind, placebo‐controlled, crossover design with two experimental test sessions to investigate the response to psilocybin (25 mg) in healthy subjects after pretreatment with escitalopram or placebo....