Frontiers in Psychiatry
February 21, 2020
Max Wolff, Ricarda Evens, Lea J. Mertens et al.
188 citations
A conceptual model proposes that psychedelic-assisted therapies reduce experiential avoidance and increase acceptance through mechanisms similar to those in cognitive behavioral therapy. In controlled clinical settings, psychedelics relax avoidance-related beliefs, boosting motivation for acceptance via operant conditioning. This allows relatively avoidance-free exposure to intensified private events, where relaxed beliefs encounter corrective information and become revised. Such belief revision may explain lasting increases in acceptance and decreases in psychopathology. The article outlines open research questions and clinical implications.
Neuroscience Applied
January 1, 2022
Lea J. Mertens, Michael Koslowski, Felix Betzler et al.
40 citations
Clinical trials with psychedelics like psilocybin face unique methodological challenges, particularly the difficulty of maintaining blinding due to the substances' pronounced subjective effects, which raises risks of expectation bias and nocebo effects. A phase II randomized, double-blind, active placebo-controlled parallel group trial with 144 patients is underway to evaluate psilocybin's efficacy and safety in treatment-resistant major depression. The trial, called EPIsoDE, is funded by the German Federal Ministry of Education and Research and addresses these challenges in its design.
Frontiers in Human Neuroscience
February 16, 2023
Michael Koslowski, Max-Pelgrom de Haas, Tamara Fischmann
14 citations
Dreaming arises from the same hierarchical predictive processing that governs waking cognition, but with key modifications: lack of sensory and motor input and a predominance of associative, non-rational primary process thinking. Emotional needs guide behavior via a value system generating pleasure and unpleasure, and the brain constantly updates its predictions to minimize prediction error. Repressed priors—mental events that cannot be reconsolidated despite ongoing error signals—correspond to conflictual complexes and may become accessible in symbolic form during dreams and psychedelic states. Evidence from neuroimaging supports this framework, and an ongoing trial with stroke patients who lost the ability to dream tests whether dreaming is necessary for intact sleep architecture and memory consolidation.
Psychedelic Medicine
January 20, 2025
Marianna Graziosi, Gabrielle Agin-Liebes, Mary P Cosimano et al.
9 citations
Psilocybin and other serotonergic psychedelics are used in research settings with safety measures including controlled environments, staff presence, screening, and psychoeducation. An analysis of study materials from psilocybin trials over the past two decades found that psychoeducation documents varied but commonly emphasized biological and physical safety, psychological safety and well-being, aspects of setting, and the potential for expectancies. The materials prioritized biological and psychological safety across all sites. The authors also identified elements unrelated to safety that may contribute to participant expectancies and suggest these extrapharmacological factors be studied systematically to maximize safety while minimizing extraneous expectancies.
Psychedelic Harm Reduction
January 1, 2026
Michael Koslowski, Peter Gasser
6 citations
Psychedelic substances show therapeutic promise but can cause distressing episodes known as challenging experiences or bad trips. Three case reports illustrate the problem and inform strategies for management. A stepwise approach is outlined, including helpful interventions, supportive care, and rescue medication, to ensure well-being and prevent complications or long-term harm.
Die Psychotherapie
February 9, 2024
Dimitris Repantis, Michael Koslowski, Sascha Benjamin Fink
4 citations
Clinical research on psychedelic-assisted therapy for mental disorders has resumed in recent years, with a steadily increasing number of studies and publications. This has raised many ethical questions that have not yet been sufficiently examined and answered. This article provides an overview of the state of clinical research and then addresses the central ethical issues arising from this particular form of therapy. Using current literature and examples from an ongoing study in Germany, ethical questions are examined in detail.
Journal of psychopharmacology (Oxford, England)
May 1, 2026
Grace Viljoen, Henrik Walter, Antonia Bendau et al.
3 citations
A systematic review of 54 studies found that the intensity of the acute psychedelic experience, particularly mystical-type experiences, is the most frequently reported predictor of therapeutic response in psychedelic-assisted therapy for mental disorders, though this was not consistent across all disorders or time points. Factors related to set, setting, and dose were associated with the likelihood and intensity of these experiences. The review included adult populations with substance-use disorders, major depressive disorder, anxiety disorders, obsessive-compulsive disorder, post-traumatic stress disorder, and existential distress, as well as naturalistic samples.
npj Mental Health Research
July 10, 2026
Constantin Volkmann, Michael Seitz, Ricarda Evens et al.
Among Berlin university students followed for one year, first-time psychedelic users showed small increases in Openness and decreases in Conscientiousness compared to never-users. After adjusting for age, sex, income, psychiatric diagnosis, and baseline substance use, the changes were attenuated and not statistically significant after correction for multiple comparisons. Exploratory analyses indicated that first-time users with psychiatric diagnoses experienced larger reductions in Neuroticism. The personality changes were not clearly different from those seen in first-time users of other illicit substances, and the authors caution against causal interpretation.
Psychotherapy and psychosomatics
May 27, 2026
Lea J Mertens, Felix Betzler, Manuela Brand et al.
A single 25 mg dose of psilocybin, or two such doses given six weeks apart, combined with psychotherapy produced a stable and clinically meaningful reduction in depression symptoms for up to twelve months in people with treatment-resistant depression. The average improvement on the Hamilton Rating Scale for Depression was about 7.9 points at six months and 7.7 points at twelve months, with no significant difference between dosing groups. Restarting standard antidepressant medication during follow-up was strongly linked to higher depression scores. This naturalistic follow-up of a phase 2b trial is the largest and most complete long-term assessment of psilocybin for depression to date.