News Releases

MAPS’ Phase 3 Trial of MDMA-Assisted Therapy for PTSD Achieves Highly Statistically Significant Results for Patients with Severe, Chronic PTSD
  • The highly statistically significant results and excellent safety record suggest MDMA-assisted therapy will be an effective treatment for severe, chronic PTSD
  • 67% of participants who received three MDMA-assisted therapy sessions no longer qualified for a PTSD diagnosis and 88% experienced a clinically meaningful reduction in symptoms
  • The pivotal Phase 3 trial treated 90 patients with severe, chronic PTSD from any cause with an average duration of 14 years and replicated the results of Phase 2 trials
  • Study participants included patients with PTSD caused by combat-related events; accidents; abuse; and sexual harm; 84% have a history of developmental trauma
  • MAPS is hopeful that these results will facilitate FDA approval in 2023 for this Breakthrough-designated therapy 

The first Phase 3 trial of MDMA-assisted therapy for posttraumatic stress disorder (PTSD) replicated and expanded on Phase 2 results indicating MDMA-assisted therapy may be an effective and cost-saving treatment for PTSD resulting from any cause. Nature Medicine is expected to publish the peer-reviewed paper detailing the results of the study sponsored by the Multidisciplinary Association of Psychedelic Studies (MAPS) and conducted by MAPS Public Benefit Corporation (MAPS PBC), a wholly-owned subsidiary of MAPS. In this first Phase 3 trial of any psychedelic-assisted therapy, participants who received MDMA-assisted therapy reported a significant reduction in PTSD symptoms compared to those who received placebo with therapy (p<0.0001), successfully achieving the prespecified primary endpoint for the trial. In fact, 67% of the group who received MDMA, compared to 32% of the group who received placebo, no longer qualified for a PTSD diagnosis after three treatment sessions. In addition, participants treated with MDMA-assisted therapy had statistically significant reductions for the key secondary endpoint of functional impairment relative to placebo with therapy (p=0.0116).

Jennifer Mitchell, Ph.D., lead author of the paper, calls attention to the results for those with the dissociative subtype of PTSD, with depression, or who reported a history of alcohol or substance use. “People with the most difficult-to-treat diagnoses, often considered intractable, respond just as well to this novel treatment as other study participants. In fact, participants diagnosed with the dissociative subtype of PTSD experienced a greater reduction in symptoms than those without the dissociative subtype.”

Mitchell added that MDMA serves as a catalyst to therapy: “MDMA is an experiential therapeutic and therefore necessitates the appropriate set and setting to truly guide change and recovery. While many forms of PTSD therapy involve recalling previous trauma, the unique ability of MDMA to raise compassion and understanding while tamping down fear is likely what enables it to be so effective.”

The randomized, blinded, Phase 3 trial, designed under a Special Protocol Assessment with the FDA, treated 90 patients with severe, chronic PTSD. Participants were randomized to receive three sessions of either MDMA or placebo with identical talk therapy. Forty-six participants received MDMA therapy and 44 participants received therapy with placebo. The primary efficacy endpoint was based on the change from baseline in an independently assessed clinical interview of PTSD severity after 18 weeks. The assessors also measured average change in functional impairment in work/school, social, and family life. Among the participants in the MDMA-assisted therapy group, 67% no longer qualified for PTSD diagnosis after three MDMA-assisted therapy sessions and 88% of participants experienced a clinically significant reduction in symptoms, while in the placebo group, 32% no longer qualified for PTSD diagnosis at the two-month follow-up and 60% experienced a clinically significant reduction in symptoms.

In the Phase 3 trial, the investigators observed no serious safety or tolerability issues in the MDMA group. MDMA did not increase the risk of suicidal thoughts or behaviors and did not increase cardiovascular risk or abuse potential relative to therapy with placebo. As expected from previous clinical trials, temporary increases in blood pressure and pulse were observed during MDMA sessions; adverse events such as muscle tightness, decreased appetite, nausea, sweating, and feeling cold were transient.

PTSD is a profoundly challenging condition with unmet medical need. Bessel van der Kolk, M.D., a leading PTSD researcher and author of the foundational book on PTSD, The Body Keeps the Score, served as Principal Investigator for the Boston study site. He explains, “The experience of having been traumatized profoundly alters perceptions; self-experience; and capacity to plan, imagine and anticipate. For 88% of people who receive this treatment, we can expect to see a treatment response. This can lead to fundamental shifts in our subjects’ perspective on self-capacity, affect regulation, and attitude towards those around them. It takes a great deal of courage to address one’s PTSD, particularly when other treatments have failed. These results open the door to a potentially powerful new pathway to healing — once MDMA-assisted therapy has been approved as a treatment for PTSD.”

Listed as a Schedule I drug, MDMA presently is defined as having “no medical benefit” and, therefore, is not currently accessible as a potential treatment for PTSD or other conditions except as administered in clinical trials. “As a result of this study and through the persistent and consistent application of scientific rigor, we have demonstrated that MDMA-assisted therapy is likely to provide relief for people diagnosed with PTSD,” noted MAPS Executive Director Rick Doblin, Ph.D. “Far from having no medical benefit MDMA, when combined with talk-therapy in this protocol, has the potential to catalyze the therapeutic process and generate positive mental health outcomes.”

Michael Mithoefer, M.D., who serves as Senior Medical Director for Medical Affairs, Training, and Supervision, led the team that developed the therapy manual and trained the 70 therapists who provided the treatment in the Phase 3 study. He celebrated their efforts, stating, “The therapists and expert research team who have brought us here are at the vanguard of what may be a revolution in mental health care. The success of this pivotal study is a major step toward regulatory approval, and we hope these results will attract many more researchers and clinicians to join the effort to further explore and deliver MDMA-assisted therapy so we can together address our national – and global – mental health crisis.”

MAPS PBC develops and delivers therapy training programs and is responsible for the development of MDMA as a medicine. MAPS PBC CEO Amy Emerson describes its mandate: “MAPS Public Benefit Corporation is establishing a new paradigm in drug research, development, and commercialization in which we center our efforts wholly on the beneficiaries of our healing modality rather than shareholders. This approach commits us to open science and open books as we research best practices for psychedelic-assisted therapy. Ultimately, any proceeds from our work will be reinvested to generate more research, more training, and more affordable options for treatment.”

A second Phase 3 clinical trial is currently enrolling participants. Prior to the hopeful approval in 2023 of MDMA-assisted therapy for PTSD, the FDA has granted permission for an expanded access program in which 50 patients can receive the treatment prior to FDA approval. MAPS plans to conduct additional studies to explore the potential of the treatment for other mental health conditions and with other treatment protocols such as group therapy and cognitive-behavioral conjoint therapy for couples. Additionally, MAPS is funding a formal commitment to health equity: a holistic plan to create more pathways to access MDMA-assisted therapy for those historically marginalized by the mental health field and society at large.

Summaries of study data and more information are provided in the MAPS Newsroom.


The safety and efficacy of MDMA-assisted therapy is currently under investigation. It has not yet been approved by the FDA, does not work for everyone, and carries risks even in therapeutic settings. These statements are no guarantee of future FDA approval or availability of MDMA-assisted therapy. These statements necessarily involve known and unknown risks and uncertainties, which may cause actual outcomes to differ materially from our projections.



Betty Aldworth, Director of Communications or

831-429-6362 ext 303


Founded in 1986, MAPS is a 501(c)(3) non-profit research and educational organization that develops medical, legal, and cultural contexts for people to benefit from the careful uses of psychedelics and marijuana. MAPS is sponsoring the most advanced psychedelic therapy research in the world: Phase 3 clinical trials of MDMA-assisted therapy for PTSD. Since its founding, MAPS has raised over $100 million for psychedelic therapy and medical marijuana research and education and has earned the Guidestar Platinum Seal of Transparency.


MAPS Public Benefit Corporation (MAPS PBC) catalyzes healing and well-being through psychedelic drug development, therapist training programs, and sales of prescription psychedelics while prioritizing public benefit above profit. Founded in 2014, MAPS PBC is a wholly-owned subsidiary of the Multidisciplinary Association for Psychedelic Studies (MAPS), a 501(c)(3) non-profit organization.