Journal of Affective Disorders Reports
July 1, 2026
Abigail E. Calder, Vincent J Diehl, Bernd Hinney et al.
Background Serotonergic psychedelics and MDMA may improve mental health through reductions in neuroticism and changes in personal values. While decreases in neuroticism following serotonergic psychedelics are sometimes observed, it is unclear which facets of neuroticism respond the most, and MDMA remains understudied. People also report value shifts after psychedelic experiences, but...
Neuropsychopharmacology
June 18, 2026
Abigail E. Calder, Vincent J Diehl, Morten P. Lietz et al.
Preclinical studies suggest that lysergic acid diethylamide (LSD) may induce lasting changes in brain function and learning ability, but evidence in humans is uncertain. Motor learning, in particular, has clinical relevance but has not been investigated in human studies of psychedelics. Forty-five healthy subjects (24 women) participated in this randomized crossover trial comparing 100 µg LSD...
Journal of psychopharmacology (Oxford, England)
May 1, 2026
Vincent J Diehl, Abigail E. Calder, Gregor Hasler
Existing tools assess psychedelic experiences, but none specifically measure altered processing of traumatic memories-a key mechanism in trauma-focused therapies and psychotherapy in general. The helioscope effect describes how psychedelics like psilocybin and 3,4-methylenedioxymethamphetamine (MDMA) enable revisiting challenging or traumatic experiences while remaining protected from...
Therapeutic Advances in Psychopharmacology
2026
Kristian Beichmann, Polina Catzeflis, Helena Aicher et al.
The Swiss Federal Office of Public Health provides case-by-case exemptions allowing physicians to provide psychedelic-assisted therapy (PAT) using psilocybin, lysergic acid diethylamide (LSD), or 3,4-methylenedioxy-N-methamphetamine (MDMA). The study provided an overview of PAT as currently provided in Switzerland under the regulatory framework of the Federal Office of Public Health (FOPH)....
Current Topics in Behavioral Neurosciences
April 29, 2025
Abigail E. Calder, Vincent J Diehl, Gregor Hasler
14 citations
Psychedelic experiences involving extreme feelings of horror, helplessness, and perceived threats can be traumatizing. Traumatic psychedelic experiences are a rare, extreme, and largely preventable form of challenging experience which can arise due to frightening psychedelic drug effects, unsafe settings, and emergence of pre-existing trauma. Some people recover quickly, but others develop...
Biological Psychiatry Global Open Science
March 1, 2025
Abigail E. Calder, Clifford Qualls, Gregor Hasler et al.
5 citations
The Hallucinogen Rating Scale (HRS) has been widely used to measure the subjective effects of psychedelics and other psychoactive substances. Its advantages include a basis in phenomenological interviews and clinical studies, straightforward items, and broad coverage of psychedelic effects. Previous studies have attempted to resolve its factor structure but were limited by small samples of...
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...
Molecular Psychiatry
November 29, 2024
Adrian Hase, Gregor Hasler, Abigail E. Calder
12 citations
Abstract Background Peripheral levels of brain-derived neurotrophic factor (BDNF) are often used as a biomarker for the rapid plasticity-promoting effects of ketamine, psychedelics, and other psychoplastogens in humans. However, studies analyzing peripheral BDNF after psychoplastogen exposure show mixed results. In this meta-analysis, we aimed to test whether the rapid upregulation of...
Journal of Affective Disorders
November 15, 2024
Abigail E. Calder, Gregor Hasler
20 citations
Studies of psychedelic-assisted therapy with LSD, psilocybin, MDMA, and related substances show clinical promise but inadequately assess side effects. Measuring side effects is challenging because they are not always easily differentiated from treatment effects or disease symptoms and show high heterogeneity, variable duration and impact, and sensitivity to context. A systematic questionnaire...
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,...
Journal of Psychopharmacology
January 12, 2024
Antonin Rouaud, Gregor Hasler, Abigail E. Calder
36 citations
Though microdosing psychedelics has become increasingly popular, its long-term effects on cardiac health remain unknown. Microdosing most commonly involves ingesting sub-threshold doses of lysergic acid diethylamide (LSD), psilocybin, or other psychedelic drugs 2–4 times a week for at least several weeks, but potentially months or years. Concerningly, both LSD and psilocybin share structural...
European Neuropsychopharmacology
June 21, 2023
Seline Mock, Nicole Friedli, Patrick Pasi et al.
46 citations
Eating disorders are serious illnesses showing high rates of mortality and comorbidity with other mental health problems. Psychedelic-assisted therapy has recently shown potential in the treatment of several common comorbidities of eating disorders, including mood disorders, post-traumatic stress disorder, and substance use disorders. The theorized therapeutic mechanisms of psychedelic-assisted...
JAMA Psychiatry
May 31, 2023
Abigail E. Calder, Gregor Hasler
14 citations
This Viewpoint proposes methods for optimizing patient and therapist safety during psychedelic-assisted psychotherapy.
J Psychopharmacol
February 28, 2023
Polina Ponomarenko, Federico Seragnoli, Abigail E. Calder et al.
22 citations
BACKGROUND: Despite the growth of psychedelic research, psychedelic-assisted group psychotherapy (PAGP) has received little attention in comparison to individual psychedelic-assisted psychotherapy models. METHODS: In this article, we aim to discuss the therapeutic potential of PAGP, as well as outline existing models and the challenges of this approach. Using Irvin Yalom's 11 therapeutic...
Neuropsychopharmacology : official publication of the American College of Neuropsychopharmacology
2023
Abigail E. Calder, Gregor Hasler
303 citations
Classic psychedelics, such as LSD, psilocybin, and the DMT-containing beverage ayahuasca, show some potential to treat depression, anxiety, and addiction. Importantly, clinical improvements can last for months or years after treatment. It has been theorized that these long-term improvements arise because psychedelics rapidly and lastingly stimulate neuroplasticity. The focus of this review is...