Psychedelics & Consciousness
MDMA-Assisted Therapy for Severe PTSD: A Phase 3 Randomized Trial
Mitchell et al. · 2021 · Nature Medicine
First Phase 3 RCT of MDMA-assisted therapy for post-traumatic stress disorder.
Research objective
Evaluate efficacy and safety of three MDMA-assisted psychotherapy sessions plus integration in severe PTSD.
Methodology
Randomized double-blind placebo-controlled trial in 90 participants. CAPS-5 used as primary outcome. Manualized therapy delivered by trained co-therapist dyads.
Key findings
- Large effect size (Cohen's d ≈ 0.91) on CAPS-5 versus placebo.
- Approximately two-thirds of MDMA participants no longer met PTSD criteria at the primary endpoint.
- Generally favorable safety profile in a screened population.
Strengths
- Multi-site, manualized therapy, intent-to-treat analysis.
- Clinically meaningful effect sizes in a difficult population.
Limitations
- Functional unblinding ~90%.
- FDA 2024 review raised methodological and adverse-event reporting concerns; revised submissions are in progress.
Practical implications
- Established MDMA-assisted therapy as a plausible new treatment paradigm for PTSD.
- Catalyzed regulatory and methodological debate that is reshaping psychedelic trial design.
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