Psychedelic-Assisted Psychotherapy for the Treatment of PTSD: A Systematic Review and Meta-Analysis

Post-traumatic stress disorder (PTSD) is often not well treated by current medications or talk therapies, leading to interest in psychedelic-assisted psychotherapy. A systematic review and meta-analysis of 11 randomized controlled trials with 358 participants examined MDMA, ketamine, and cannabidiol. MDMA-assisted psychotherapy produced a moderate-to-large reduction in PTSD symptoms, with more participants achieving clinical response and loss of PTSD diagnosis. Ketamine showed a small, non-significant effect, and one trial of cannabidiol found no clear benefit. All agents were generally well tolerated. The evidence is dominated by MDMA trials, and safety data remain insufficient for strong comparisons. More studies with standardized outcomes and direct comparisons are needed.

Study at a glance

Abstract

Post-traumatic stress disorder (PTSD) remains inadequately treated by existing pharmacological and psychological interventions, prompting growing interest in psychedelic-assisted psychotherapy. Although randomised controlled trials have evaluated several psychedelic agents for PTSD, to our knowledge, no prior PTSD-specific synthesis has quantitatively examined multiple agent classes within a single review framework. This systematic review and meta-analysis searched PsycINFO, CINAHL, Embase, MEDLINE, and clinical trial registries to identify RCTs of psychedelic-assisted psychotherapy for PTSD. Risk of bias was assessed using the Cochrane Risk of Bias 2 tool, and random-effects meta-analyses were conducted for efficacy outcomes; safety and therapeutic protocols were synthesised narratively. Eleven RCTs involving 358 participants met inclusion criteria, evaluating MDMA, ketamine, and cannabidiol, of which eight contributed to meta-analyses. MDMA-assisted psychotherapy demonstrated a significant moderate-to-large reduction in PTSD symptom severity with negligible heterogeneity, and participants were significantly more likely to achieve clinical response and loss of PTSD diagnosis. The pooled effect for ketamine was small and non-significant, and a single cannabidiol trial showed no clear benefit. All agents were generally well tolerated. MDMA-assisted psychotherapy showed a promising efficacy signal for PTSD symptom reduction, although safety data were heterogenous and remain insufficient for strong comparative conclusions. Evidence for ketamine and cannabidiol remains too limited to support clinical implementation and it is noted that the current evidence base is dominated by MDMA trials. Further adequately powered trials with standardised outcomes and direct comparative studies across agents are needed.