Psychological support in psychedelic-assisted therapy clinical trials: A systematic review

RATIONALE: The nature and role of the psychological support provided in psychedelic-assisted treatments for psychiatric disorders are currently the object of debate. How this support is conceptualized-as a vector for therapeutic change or framework for risk minimization-has far-reaching consequences in terms of how these treatments should be regulated, delivered, and studied. OBJECTIVES: To determine whether psychological interventions in psychedelic trials meet accepted definitions of psychotherapy using a common factors framework. We assess whether self-described psychedelic-assisted psychotherapies align with psychotherapy criteria and whether trials where support is not defined as psychotherapy nonetheless embed psychotherapeutic elements. METHODS: Following Preferred Reporting Items for Systematic Reviews and Meta-Analyses (PRISMA) guidelines, we searched PubMed and PsycINFO in January 2024 for all available clinical trials of psilocybin, MDMA, or lysergic acid diethylamide reporting any psychological support. Articles were assessed against a 4-item common factors framework. RESULTS: We screened 224 records, reviewed 52 full-text documents, and included 29 clinical trials (449 patients). Of the 29 trials, 69% met all 4 factors. Of the 19 psychotherapy-labeled trials, 84% met all 4 factors. Of the 10 non-psychotherapy-labeled studies, 40% met 4 factors. CONCLUSIONS: Findings indicate that the psychological interventions in most therapeutic psychedelic trials qualify as psychotherapy. We highlight the clinical implications in terms of clinician training and treatment timeframe. We emphasize the ethical imperative to measure and address the intervention complexity inherent to psychedelic trials, to optimize clinical outcomes and safeguard patients.