3,4-methylenedioxymethamphetamine (MDMA)-assisted psychotherapy for victims of sexual abuse with severe post-traumatic stress disorder: an open label pilot study in Brazil

The study reports outcomes for three participants who completed MDMA-assisted psychotherapy (MDMA-AP) for severe post-traumatic stress disorder (PTSD) secondary to sexual abuse. The primary outcome was the Clinician Administered PTSD Scale for DSM-IV (CAPS-4) score measured at baseline and two months after the final MDMA-AP session. Secondary outcomes included self-report and clinician-rated instruments: the PTSD Checklist – Civilian Version (PCL‑C), the Post-Traumatic Growth Inventory (PTGI), the Columbia‑Suicide Severity Rating Scale, the Beck Depression Inventory‑II (BDI‑II), the Dissociative Experiences Scale‑II, the Pittsburgh Sleep Quality Index, and the DSM‑IV Global Assessment of Functioning (GAF). Subjective effects of MDMA were assessed with the Mystical Experience Questionnaire and the Subjective Units of Distress Scale. Change in secondary outcomes was calculated as the difference between baseline and two months post-treatment and interpreted using each instrument’s established cut-offs or ranges. Numerical results reported by R. and colleagues indicate clinically meaningful reductions in clinician-rated PTSD severity. Baseline CAPS-4 scores and two-month follow-up scores for the three completers were reported as 90 → 61, 78 → 27, and 72 → 8. Each participant’s reduction exceeded 25 points and all reductions were greater than 30%, which the authors treat as clinically significant: a 29-point (32%) reduction, a 51-point (65%) reduction, and a 64-point (89%) reduction. The authors estimated a large effect size (Rosenthal’s r = 0.92) using Stata v.12, but note that this must be interpreted cautiously because of the very small sample. Secondary measures generally supported improvement in PTSD and related domains. On the PCL‑C, one participant moved from high severity to little or no severity, while the other two showed reductions of approximately 20 points but remained in the high severity range. PTGI scores rose substantially: approximately 5-fold and 7-fold increases in two participants and a 2.5-fold increase in the third. Depressive symptoms decreased markedly on the BDI‑II: one participant shifted from severe to mild depression, and two shifted from severe to minimal, with final BDI scores of 10 and 2 reported for two participants. Changes on dissociation (Dissociative Experiences Scale‑II) and sleep quality (Pittsburgh Sleep Quality Index) were minimal. GAF scores improved from “serious” to “moderate” in one case, to “mild” in another, and to “slight” in the third. Safety data indicated no serious adverse events and no cases of hyperthermia. The most frequent adverse events were somatic pains and anguish; the authors describe adverse events as tolerable and short-lived.

R. and colleagues interpret the findings as preliminary evidence that MDMA-assisted psychotherapy may reduce PTSD severity and improve related outcomes in victims of sexual abuse with severe PTSD. They emphasise that all three completers derived benefit, with reductions in CAPS-4 scores meeting or exceeding thresholds for clinical significance. Improvements observed on self-report PTSD measures, depressive symptoms, post-traumatic growth, and global functioning are cited as converging evidence of clinical benefit. The authors position their small open-label study against larger, previously published Phase II trials that reported large effect sizes and an overall success rate of about 60% across more than 100 severe PTSD cases. They note that their effect size (r = 0.92) aligns with previous reports but must be treated cautiously due to the tiny sample and open-label design. Key limitations acknowledged by the authors are the small sample size and lack of blinding, which limit causal inference and raise the possibility of expectancy or caregiver effects. The authors also note that adverse events in this pilot were acceptable and that no serious safety signals emerged in this small cohort. With these caveats, the authors argue that further MDMA-AP research in Brazil is warranted. They justify additional studies on public-health grounds given high local rates of violence and PTSD and the limited effectiveness of existing treatments for many patients. The authors highlight that this is, to their knowledge, the first scientific study in Brazil to administer a controlled psychedelic substance to a clinical population and suggest their results should encourage further Brazilian research into psychedelic-assisted therapies. They also reference the broader research trajectory, noting that a Phase III MDMA-AP trial was underway at the time of writing and that potential regulatory approval could be anticipated in coming years.

The authors conclude that, in this small open-label pilot, all three participants with severe PTSD following sexual abuse showed clinically meaningful improvement after MDMA-assisted psychotherapy, with no serious adverse events reported. They view the findings as sufficient to justify larger, controlled MDMA-AP studies in Brazil given the burden of PTSD locally and the limited effectiveness of current treatments, while underscoring the need to interpret the results cautiously because of the study’s small size and open-label design.