A Multi-Site Phase 3 Study of MDMA-Assisted Psychotherapy for PTSD (MAPP1)

Inclusion Criteria:

* Are at least 18 years old
* Are fluent in speaking and reading the predominantly used or recognized language of the study site
* Are able to swallow pills
* Agree to have study visits recorded, including Experimental Sessions, Independent Rater assessments, and non-drug psychotherapy sessions
* Must provide a contact (relative, spouse, close friend or other caregiver) who is willing and able to be reached by the investigators in the event of a participant becoming suicidal or unreachable.
* Must agree to inform the investigators within 48 hours of any medical conditions and procedures
* If of childbearing potential, must have a negative pregnancy test at study entry and prior to each Experimental Session, and must agree to use adequate birth control through 10 days after the last Experimental Session.
* Must not participate in any other interventional clinical trials during the duration of the study
* Must be willing to remain overnight at the study site after each Experimental Session and be driven home after, and commit to medication dosing, therapy, and study procedures
* At baseline, meet DSM-5 criteria for current severe PTSD

Exclusion Criteria:

* Are not able to give adequate informed consent
* Have uncontrolled hypertension
* Have a marked baseline prolongation of QT/QTc interval (e.g., repeated demonstration of a QTc interval \>450 milliseconds \[ms\] in males and \>460 ms in females corrected by Bazett's formula)
* Have a history of additional risk factors for Torsade de pointes (e.g., heart failure, hypokalemia, family history of Long QT Syndrome)
* Have evidence or history of significant medical disorders, such as myocardial infarction, cerebrovascular accident, or aneurysm
* Have symptomatic liver disease
* Have history of hyponatremia or hyperthermia
* Weigh less than 48 kilograms (kg)
* Are pregnant or nursing, or are of childbearing potential and are not practicing an effective means of birth control
* Have an active illicit or prescription drug use disorder
* Have used Ecstasy (material represented as containing MDMA) more than 10 times within the last 10 years or at least once within 6 months of the first Experimental Session; or have previously participated in a MAPS-sponsored MDMA clinical trial.