npj Mental Health Research
July 10, 2026
Constantin Volkmann, Michael Seitz, Ricarda Evens et al.
Psychedelics may influence personality traits, but longitudinal evidence on first-time use outside clinical settings remains limited. We followed 102 first-time psychedelic users and 1066 never-users over one year among Berlin university students. Personality was assessed with the Big Five Inventory at baseline and follow-up. Linear mixed-effects models showed small relative increases in...
Psychotherapy and Psychosomatics
May 27, 2026
Lea J. Mertens, Felix Betzler, Manuela Brand et al.
Psilocybin shows promise for treatment-resistant depression (TRD), but long-term data are limited. This study examined the antidepressant effect of one or two psilocybin doses with adjunct psychotherapy in TRD until twelve months. This is a naturalistic follow-up of a phase 2b, randomized, active placebo-controlled trial, where participants were randomized to receive two drug administrations...
Journal of psychopharmacology (Oxford, England)
May 1, 2026
Grace Viljoen, Henrik Walter, Antonia Bendau et al.
3 citations
Psychedelic-assisted therapy (PAT) has demonstrated substantial efficacy across a range of mental disorders. However, heterogeneity between patients confers differential responsiveness. This systematic review aims to explore factors which may predict therapeutic responses to PAT. A systematic search was performed from inception through to March 2024 and studies that assessed predictors of...
JAMA Psychiatry
March 18, 2026
Lea J. Mertens, Michael Koslowski, Felix Betzler et al.
9 citations
Importance: Psilocybin shows promise in treating depression, although limitations of previous research warrant further research. Objective: To investigate the efficacy and safety of oral psilocybin, 25 mg, with adjunct psychotherapy in treatment-resistant depression (TRD). Design, Setting, and Participants: This was a 2-center, triple-blinded (investigator, participant, rater), phase 2b, active...
Nervenheilkunde
February 1, 2026
Dimitris Repantis, Michael Koslowski, Felix Betzler et al.
Zusammenfassung Psychedelika wie Psilocybin und LSD durchlaufen eine bemerkenswerte Geschichte, die von frühen psychiatrischen Anwendungen über den Freizeitgebrauch und die Prohibition in den 70er Jahre bis zur aktuellen Wiederentdeckung in klinischen Studien reicht. MDMA wird seit etwa 15 Jahren für die Behandlung der posttraumatischen Belastungsstörung evaluiert. In der Behandlung werden...
Psychopharmakotherapie
2026
Antonia Bendau, Felix Betzler, Twyla Michnevich et al.
1 citation
Party drugs encompass a broad spectrum of legal and illegal psychoactive substances used in party settings such as clubs, festivals, raves or private gatherings to modulate mood, perception, social interaction and bodily states. Most commonly, alcohol and cannabis are consumed, followed by amphetamine, MDMA (“ecstasy”), cocaine and ketamine. Synthetic cathinones, GHB/GBL (“liquid ecstasy”),...
Journal of Psychopharmacology
January 20, 2025
Joshua Liebnau, Felix Betzler, André Kerber
10 citations
Background: Recent clinical trials suggest promising antidepressant effects of psilocybin, despite methodological challenges. While various studies have investigated distinct mechanisms and proposed theoretical opinions, a comprehensive understanding of psilocybin’s neurobiological and psychological antidepressant mechanisms is lacking. Aims: Systematically review potential antidepressant...
Current Topics in Behavioral Neurosciences
October 23, 2024
Grace Viljoen, Felix Betzler
5 citations
There is a large and rapidly growing body of literature investigating the therapeutic effects of classic psychedelics in affective and anxiety disorders, but very few studies have examined the inverse of this, that is, the potential for psychedelics to inflict anxiety and affective symptoms. A systematic literature search was performed and 39 papers were included in the final review to...
The International journal on drug policy
April 1, 2022
Antonia Bendau, Leonard Viohl, Moritz Bruno Petzold et al.
The COVID-19 pandemic is presumably having an impact on the consumption of psychoactive substances. Social distancing and lockdown measures may particularly affect the use of "party drugs" (e.g., stimulants, dissociatives, and GHB/GBL) through the absence of typical use settings. We aimed to analyse the use patterns of those substances and underlying motivations before and during the pandemic....
Neuroscience Applied
2022
Lea J. Mertens, Michael Koslowski, Felix Betzler et al.
40 citations
Psychedelics such as psilocybin have recently gained remarkable interest in both the specialist literature and the lay press because studies suggest that these substances may have great therapeutic potential in various psychiatric disorders, including major depression. However, clinical trials with psychedelic drugs pose particular methodological challenges to researchers, some of which differ...
2021
Felix Betzler, Gerhard Gründer, Matthew W. Johnson et al.
Purpose of Review: The use of psychedelics in a therapeutical setting has been reported for the treatment of various diagnoses in recent years. However, as psychedelic substances are still commonly known for their ( illicit) recreational use, it may seem counterintuitive to use psychedelic therapy to treat substance use disorders. This review aims to discuss how psychedelics can promote and...
Frontiers in Psychiatry
February 21, 2020
Max Wolff, Ricarda Evens, Lea J. Mertens et al.
188 citations
The efficacy of psychedelic-assisted therapies for mental disorders has been attributed to the lasting change from experiential avoidance to acceptance that these treatments appear to facilitate. This article presents a conceptual model that specifies potential psychological mechanisms underlying such change, and that shows substantial parallels between psychedelic therapy and cognitive...