Date of Completion


Embargo Period



MDMA; psychoherapy; posttraumatic stress disorder; race; ethnicity

Major Advisor

Stephanie Milan, Ph.D.

Associate Advisor

Monnica T. Williams, Ph.D.

Associate Advisor

Kimberli Treadwell, Ph.D.

Field of Study



Doctor of Philosophy

Open Access

Open Access


MDMA-assisted psychotherapy was shown in previous clinical trials to be efficacious and safe for alleviating treatment-resistant posttraumatic stress disorder (PTSD). However, due to low ethnoracial diversity, the question remains as to whether ethnoracial minority participants would benefit similarly. Thus, in Study 1, ethnoracial differences in PTSD symptoms, secondary outcomes, and suicidality were examined for a multisite, open-label trial of MDMA-assisted psychotherapy. A total of 11 ethnoracial minority and 26 non-Hispanic White participants formed the modified intent-to-treat (ITT) set. General and generalized linear model analyses were used to test group differences. Correlational analyses were conducted to test relationships between changes in certain secondary outcomes/putative mechanisms of action and PTSD symptoms for the entire sample. Results indicated overall ethnoracial equivalence in efficacy and safety/suicidality, with majority large effect sizes in symptom improvement across groups. Ethnoracial minority participants seemed to self-report lower PTSD symptom reduction after the first dose, although this difference was erased after the second and third doses. Additionally, improved alexithymic tendencies, emotion regulation ability, and self-compassion were significantly correlated with reduced PTSD symptoms. These findings provided preliminary support for the efficacy and safety of MDMA-assisted psychotherapy for treating PTSD across ethnoracial groups, although more research needs to be conducted with larger, more diverse samples. In Study 2, a mixed-methods case study was conducted on an ethnoracial minority participant from the same open-label trial, to provide a culturally informed lens on recovery from PTSD in a participant of color with MDMA-assisted psychotherapy. A case profile was provided, documenting quantitative symptom improvement on all measures from Study 1. This was followed by an interpretative phenomenological analysis (IPA) of effects and mechanisms of action for this participant, based on integration session transcripts. Lastly, linguistic variables inherent within the participant’s transcripts were entered into exploratory correlational analysis with his PTSD symptom scores. Results of IPA indicated recurrent themes related to: mechanisms of change; reduced PTSD symptoms; additional effects beyond PTSD symptom reduction; and navigating interpersonal relationships. Correlational findings indicated meaningful relationships between several linguistic variables (e.g., increased authenticity) and PTSD symptom reduction. Lastly, recommendations for diversifying ongoing MDMA-assisted psychotherapy trials were provided.