High-Intensity Inpatient MDMA-Assisted Psychotherapy for PTSD

Inclusion Criteria: * At least 18 years old. * Able to provide written informed consent. * Fluent in speaking and reading Dutch. * Able to swallow pills. * Body weight of at least 48 kg. * Meet DSM-5 criteria for current PTSD. * Meet criteria for treatment-refractory PTSD. * Currently in treatment at ARQ Centre'45. * Agree to have study visits audiovisually recorded. * Able to provide a contact (relative, spouse, close friend, or other support person) who is willing and able to be reached by the investigators in the event of the participant becoming unwell or unreachable. Exclusion Criteria: * Has a history of any medical condition that could make receiving a sympathomimetic drug harmful because of increases in blood pressure and heart rate. * Has uncontrolled hypertension. * Has a recent history of clinically significant hyponatremia or hyperthermia. * Has current unstable liver or biliary disease. * Unable or unwilling to safely taper-off prohibited psychiatric medication. * Has engaged in a new form of psychiatric or mental health care within 12 weeks of enrollment, including Electroconvulsive Therapy (ECT). * Has a medical or psychiatric condition that could interfere with study participation or pose a risk to the participant's safety or well-being. * Has any current problem which, in the opinion of the investigator, might interfere with study participation.