Group psychedelic-assisted therapy for mental health conditions: a mixed-methods systematic review

BackgroundThe group therapy model has been recently favored as a means of conducting psychedelic assisted therapies for mental health disorders. However, there is a paucity of literature showing strengths or drawbacks of this approach and comparisons of safety and efficacy to individual therapy. This systematic review aims to address this gap in literature.MethodsWe included original research of group psychedelic therapy programs that were peer reviewed and published in English or where a translation was available or possible. Participants must be 18 or older and have a psychiatric diagnosis. We searched for MEDLINE, Scopus, and APA PsychInfo until January 1 2026. Screening, data extraction, and appraisal using the Mixed Methods Appraisal Tool (MMAT) were conducted by two independent researchers. A parallel-results convergent synthesis design was employed consisting of independent syntheses of qualitative and quantitative evidence and an interpretation of the results in the discussion.ResultsWe included 30 papers representing 22 unique group therapy protocols. Demographics were inconsistently reported: sex or gender was reported in 18 papers, race/ethnicity in eight papers. Fifteen papers reported pre–post outcomes using validated screening tools for mental health, functioning, substance use, or wellbeing. Using a segregated methodologies approach, quantitative and qualitative findings were broadly complementary. Quantitative results showed overall decreases in validated scale outcomes reflecting improvement in depression, anxiety, trauma symptoms, functioning, and other psychiatric outcomes. Qualitative results described improvements in mindfulness, emotional processing, psychological flexibility, meaning-making, and social connectedness supported by the group format.DiscussionDespite emerging mechanistic evidence for direct effects of psychedelic molecules on the brain, only a minority of studies used comparison groups, and only one was a modern randomized controlled trial. Group PaT may not only be pragmatically beneficial for feasibility and cost-effectiveness, but may also contribute to therapeutic outcomes through peer support, normalization, belonging, and integration. Limitations of this systematic review include substantial heterogeneity in molecules, populations, protocols, outcome measures, and follow-up duration, as well as overlapping cohorts and few studies with group components throughout the entire course of treatment.Systematic review registrationPROSPERO: https://www.crd.york.ac.uk/PROSPERO/view/CRD42024491478, identifier: CRD42024492648.