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Anna M Becker

28 papers in the library · 1,099 citations · publishing 2021-2026

Papers

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LSD therapy: A few hundred meters from where it began.

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.

Comparison of acute effects of 3,4-methylenedioxymethamphetamine (MDMA) with and without a supplemental booster dose in healthy participants: a double-blind, randomized, placebo-controlled, crossover study

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...

Integrating the Mystical Experience Questionnaire Into a Broader Psychometric Framework: English Validation of the Psychedelic Experience Scale and Comparison of Psilocybin and LSD Sessions Across Two Controlled Settings.

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...

Neuroplastic white matter changes in patients with major depression following lysergic acid diethylamide treatment

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...

Integrating the Mystical Experience Questionnaire Into a Broader Psychometric Framework: English Validation of the Psychedelic Experience Scale and Comparison of Psilocybin and LSD Sessions Across Two Controlled Settings

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...

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...

Efficacy and safety of low- versus high-dose-LSD-assisted therapy in patients with major depression: A randomized trial.

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...

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...

Acute Effects and Pharmacokinetics of LSD after Paroxetine or Placebo Pre‐Administration in a Randomized, Double‐Blind, Cross‐Over Phase I Trial

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,...

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 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...

Pharmacological and non-pharmacological predictors of the LSD experience in healthy participants.

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...

Safety pharmacology of acute psilocybin administration in healthy participants

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...

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...

The revival of the psychedelic experience scale: Revealing its extended-mystical, visual, and distressing experiential spectrum with LSD and psilocybin studies

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...

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...

Pharmacokinetics and Pharmacodynamics of Oral Psilocybin Administration in Healthy Participants

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...

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...