Additional MDMA-assisted Therapy for People Who Relapsed After MDMA-assisted Therapy Trial

Inclusion Criteria:

* Be diagnosed with chronic PTSD;
* Have a CAPS score showing moderate to severe PTSD symptoms;
* Have participated in MP-1;
* Are at least 18 years old;
* Must be generally healthy;
* Must sign a medical release for the investigators to communicate directly with their therapist and doctors;
* Are willing to refrain from taking any psychiatric medications during the study period;
* Willing to follow restrictions and guidelines concerning consumption of food, beverages, and nicotine the night before and just prior to each experimental session;
* Willing to remain overnight at the study site;
* Agree to have transportation other than driving themselves home or to where they are staying after the integrative session on the day after the MDMA session;
* Are willing to be contacted via telephone for all necessary telephone contacts;
* Must have a negative pregnancy test if able to bear children, and agree to use an effective form of birth control;
* must provide a contact in the event of a participant becoming suicidal;
* Are proficient in speaking and reading English;
* agree to have all clinic visit sessions recorded to audio and video
* Agree not to participate in any other interventional clinical trials during the duration of this study.

Exclusion Criteria:

* Are pregnant or nursing, or if a woman who can have children, those who are not practicing an effective means of birth control;
* Weigh less than 48 kg;
* Are abusing illegal drugs;
* Are unable to give adequate informed consent;
* Upon review of past and current drugs/medication must not be on or have taken a medication that is exclusionary;
* Upon review of medical or psychiatric history must not have any current or past diagnosis that would be considered a risk to participation in the study.