Towards therapeutic paths with mindfulness meditation–based and psychedelics assisted psychotherapies in PTSD: Randomized controlled trials systematic review and meta-analysis

Both mindfulness meditation-based interventions and psychedelic-assisted psychotherapies reduce PTSD symptoms in adults with moderate effect sizes. Mindfulness interventions showed a standardized mean difference of 0.45, while psychedelic therapies showed 0.54. MDMA-assisted therapy produced slightly stronger outcomes than ketamine. Psychedelic studies had tighter confidence intervals and lower risk of bias than mindfulness trials. Psychedelic therapies may yield a marginally larger effect, but mindfulness interventions are easier to disseminate. Future research should examine long-term efficacy, adverse events, and diverse populations, and investigate altered states of consciousness as a shared therapeutic mechanism.

Study at a glance

Abstract

The purpose of this study was to compare mindfulness meditation-based interventions (MMBIs) and psychedelic-assisted psychotherapies (PAP) in PTSD and examine altered-state mediators as a shared mechanism. Following PRISMA 2020 guidelines, PubMed, Web of Science, and EBSCOhost were systematically searched for randomized controlled trials (RCTs) published through January 2024. Trials reporting post-treatment changes in validated PTSD symptom measures were included, focusing on two intervention categories: MMBIs (n = 13 RCTs) and PAP (n = 9 RCTs). Standardized mean differences (SMD) were calculated under a random-effects model, with 95% confidence intervals (CIs). MMBIs produced a significant, moderate effect on PTSD symptoms (SMD=0.45, 95% CI [0.27, 0.63]; p < 0.001). PAP also demonstrated a moderate effect size (SMD=0.54, 95% CI [0.32, 0.76]; p < 0.001), with MDMA displaying slightly stronger outcomes than ketamine. PAP studies generally showed tighter confidence intervals and lower risk of bias compared to MMBI trials. Heterogeneity varied, but subgroup analyses indicated consistent effects across intervention types. Both MMBIs and PAP are efficacious in reducing PTSD symptoms among adults. While PAP appears to yield a marginally larger effect size, MMBIs offer practical advantages due to ease of dissemination. Future research should address long-term efficacy, adverse events, and culturally diverse populations. The role of altered states of consciousness in both interventions also warrant closer investigation, potentially illuminating mechanisms underlying therapeutic gains.