MDMA-Assisted Therapy Randomized Controlled Trial Incremental Effects Systematic Review and Meta-Analysis
Nicholas C. Borgogna, D. Drew Whittington, Tyler Owen, Dan Petrovitch, Jacob Vaughn, Cara Struble, Louis A. Pagano, Stephen L. Aita, Benjamin D. Hill
medRxiv Preprint Server May 5, 2026 preprint DOI: 10.64898/2026.05.05.26352468 via medRxiv
Summary
MDMA-assisted therapy (MDMA-AT) shows a significant moderate-to-large reduction in psychopathology compared to control interventions, with an effect size of 1.03 across 295 participants. The therapy was particularly effective for trauma reduction (effect size of 1.46), while effects on depression were smaller and not statistically significant (0.51). However, only 23% of studies met high-quality harm reporting standards, indicating the need for more robust clinical trials.
Study at a glance
| Design | systematic review and meta-analysis |
|---|---|
| Sample size | 295 |
| Population | participants in randomized controlled trials of MDMA-assisted therapy |
| Key finding | MDMA-AT demonstrated a significant moderate-to-large incremental reduction in psychopathology relative to controls. |
Abstract
Mental illness poses a substantial global burden, yet existing psychotherapies and psychopharmacologies often produce limited outcomes. Psychedelic-assisted therapies have re-emerged as potential transdiagnostic interventions. In particular, 3,4-methylenedioxymethamphetamine–assisted therapy (MDMA-AT) has generated interest for its rapid psychological effects and potential to enhance psychotherapy outcomes. However, the incremental efficacy of MDMA-AT relative to control interventions across transdiagnostic outcomes remains unclear. Further, there have been emerging concerns regarding harm reporting quality in MDMA-AT clinical trials. We conducted a systematic review and meta-analysis of MDMA-AT randomized controlled trials. Eleven publications representing eight controlled trials with 10 analyzed subgroups (n = 295 participants) were included in meta-analyses. Two additional secondary publications were included for harm reporting syntheses (k = 13 total). Across 114 extracted effect sizes, MDMA-AT demonstrated a significant moderate-to-large incremental reduction in psychopathology relative to controls (g = 1.03, 95% CI [0.46, 1.60]), though heterogeneity was high (I² = 76%). Incremental effects were larger versus inert placebos (g = 1.27) than active controls (g = 0.75). Symptom-specific analyses indicated strong incremental effects for trauma reduction (g=1.46 [95% CI: 0.67, 2.25]) and smaller non-significant effects for depression (g=0.51 [95% CI: −0.06, 1.08]). Harm reporting quality synthesis showed only 23% of publications met high-quality reporting standards. Overall, MDMA-AT demonstrates potential transdiagnostic efficacy, but small samples, confounding factors, and mediocre harm reporting highlight the need for larger more transparent clinical trials.