International Journal of Neuropsychopharmacology
September 9, 2026
F Holze, F Müller, P Gasser et al.
Abstract Background Anxiety disorders are a major health burden and current treatment options yield unsatisfactory results. Psychedelics, such as lysergic acid diethylamide (LSD) that act via agonism on serotonin 2A receptors, have recently been shown to be effective in the treatment of anxiety symptoms. Aims & Objectives Here, we determine the relationship between the acute experience and...
Neuropsychopharmacology : official publication of the American College of Neuropsychopharmacology
July 1, 2026
Denis Arikci, Joran Borgulya, Isabelle Straumann et al.
1 citation
Based on its in vitro profile and preliminary evidence, 4-bromo-2,5-dimethoxyphenethylamine (2C-B) may have psychoactive properties that are similar to 3,4-methylenedioxymethamphetamine (MDMA) and psilocybin, which are investigated for the treatment of posttraumatic stress disorder and depressive disorders. We compared acute effects of 2C-B (10, 20, and 30 mg), 125 mg MDMA, and 25 mg psilocybin...
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...
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...
Neuroscience Applied
2026
CA Madsen, M. Navarro, E. Kolesnik et al.
Background: Serotonergic psychedelics induce their psychoactive effects by stimulating the brain’s serotonin 2A receptor (5-HT2AR). In humans, a cerebral 5-HT2AR occupancy of ≥60% is required to elicit a profound psychedelic experience with psilocybin [1] and for pigs, a dose corresponding to ∼65% 5-HT2AR occupancy elicits headshakes [2]. We posit that in order to assess biochemical and...
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...
medRxiv
June 18, 2025
Drummond E-Wen Mcculloch, Kristian Larsen, Annette Johansen et al.
preprint
In this study, we provide the first study to integrate molecular and functional neuroimaging during psychedelic drug effects in humans. Using simultaneous PET-MRI technology, we describe multiple brain actions of lysergic acid diethylamide (LSD) in healthy volunteers. We quantify the occupancy of LSD at cerebral serotonin 2A receptors and show that LSD increases global cerebral blood flow and...
Nature Medicine
June 3, 2025
Chloé Pronovost-Morgan, Kyle T. Greenway, Leor Roseman et al.
26 citations
Psychedelic substances exhibit complex interactions with the 'set and setting' of use, that is, the mental state of the user and the environment in which a psychedelic experience takes place. Despite these contextual variables' known importance, psychedelic research has lacked methodological rigor in reporting extra-pharmacological factors. This study aimed to generate consensus-based...
Clinical pharmacology and therapeutics
May 26, 2025
Denis Arikci, Friederike Holze, Lorenz Mueller et al.
6 citations
Lysergic acid diethylamide (LSD) is currently being investigated as a potential treatment for psychiatric and neurological disorders. Different LSD formulations (base or tartrate, oral or intravenous) are being used. Unclear is whether LSD base and tartrate pharmacokinetics are equivalent. Additionally, LSD's absolute oral bioavailability is unknown. Therefore, we tested the bioequivalence of...
Drug metabolism and disposition: the biological fate of chemicals
April 28, 2025
Jan Thomann, Deborah Rudin, Selina Kraus et al.
4 citations
4-Bromo-2,5-dimethoxyphenethylamine (2C-B) is widely used recreationally and has recently gained interest as a treatment for mental health disorders. In this study, a liquid chromatography-tandem mass spectrometry method to quantify 2C-B and its metabolites 4-bromo-2,5-dimethoxyphenylacetic acid (BDMPAA) and 4-bromo-2-hydroxy-5-methoxyphenylacetic acid (B-2-HMPAA) in human plasma was developed...
Molecular Psychiatry
April 1, 2025
Mihai Avram, Lydia Fortea, Lea Wollner et al.
26 citations
Psychedelics have recently attracted significant attention for their potential to mitigate symptoms associated with various psychiatric disorders. However, the precise neurobiological mechanisms responsible for these effects remain incompletely understood. A valuable approach to gaining insights into the specific mechanisms of action involves comparing psychedelics with substances that have...
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...
Psychedelic Medicine
January 20, 2025
Marianna Graziosi, Gabrielle Agin-Liebes, Mary P Cosimano et al.
9 citations
Introduction: Serotonergic psychedelics, serotonin 2A receptor agonists such as psilocybin that can result in substantially altered states of consciousness, are used in recreational and research settings. The safety of psychedelic experiences in research settings is supported by controlled physical environments, presence of clinical and medical staff to address emergent issues, screening for...
Frontiers in Psychiatry
2025
Peter Gasser, Matthias E. Liechti, Friederike Holze
2 citations
A 64-year-old male patient who suffered from traumatic life experiences and neuropathic pain after oncological chemotherapy was treated with medium to high doses of lysergic acid diethylamide (LSD) and high doses and microdoses of methylenedioxymethamphetamine (MDMA). At the beginning of treatment, the patient did not experience any acute subjective effects of LSD at a dose of 200 µg. After...
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...
JAMA Network Open
November 4, 2024
Cihan Atila, Isabelle Straumann, Patrick Vizeli et al.
15 citations
3,4-Methylenedioxymethamphetamine (MDMA, or ecstasy) is a recreational drug being investigated for the treatment of posttraumatic stress disorder. Acute hyponatremia is a potentially serious complication after even a single dose of MDMA. The assumed etiology has been a vasopressin release inducing the syndrome of inappropriate antidiuresis combined with increased thirst, causing polydipsia and...
Journal of Psychopharmacology
September 20, 2024
Abigail E. Calder, Benjamin Rausch, Matthias E. Liechti et al.
17 citations
Background: Psychedelic-assisted therapy (PAT) is permitted in Switzerland under its limited medical use program. Data from patients in this program represent a unique opportunity to analyze the real-world practice of PAT. Aims: This study compared the subjective effects of lysergic acid diethylamide (LSD) and psilocybin between patients undergoing PAT and healthy volunteers. For the patients,...
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...
The British journal of psychiatry : the journal of mental science
September 1, 2024
Friederike Holze, Peter Gasser, Felix Müller et al.
32 citations
Anxiety disorders are a major public health burden with limited treatment options. We investigated the long-term safety and efficacy of lysergic acid diethylamide (LSD)-assisted therapy in patients with anxiety with or without life-threatening illness. This study was an a priori-planned long-term follow-up of an investigator-initiated, two-centre trial that used a double-blind,...
European Neuropsychopharmacology
August 9, 2024
Friederike Holze, M. Madsen, Claus Svarer et al.
16 citations
The serotonin 2A (5-HT2A) receptor is an important target for drug development and the main receptor through which classical psychedelics elucidate their hallucinogenic effects. The 5-HT2A receptor antagonist ketanserin has frequently been used as a tool to block the receptor. Here, we establish the dose-occupancy relation of ketanserin and the cerebral 5-HT2A receptor in healthy participants...
Current Topics in Behavioral Neurosciences
July 31, 2024
Friederike Holze, Matthias E. Liechti, Felix Müller
4 citations
Psychedelics are a group of substances within the heterogeneous class of hallucinogenic drugs. Via binding to the serotonin (5-HT) 2A receptor, psychedelics exert profound alterations in various mental domains, including sensation, cognition, emotions, and self-perception. Psychedelics comprise phenethylamines (e.g., mescaline), tryptamines (e.g., psilocybin), and ergolines (e.g., LSD). These...
Biological psychiatry. Cognitive neuroscience and neuroimaging
May 1, 2024
Mihai Avram, Felix Müller, Katrin H. Preller et al.
13 citations
While the exploration of serotonergic psychedelics as psychiatric medicines deepens, so does the pressure to better understand how these compounds act on the brain. We used a double-blind, placebo-controlled, crossover design and administered lysergic acid diethylamide (LSD), 3,4-methylenedioxymethamphetamine (MDMA), and d-amphetamine in 25 healthy participants. By using spectral dynamic causal...