Open Label Study of MDMA-assisted Psychotherapy for Treatment of PTSD With Optional fMRI Sub-Study

The goal of this clinical trial is to learn if MDMA-assisted therapy is safe and effective in people diagnosed with at least severe PTSD. The main question it aims to answer is: Do two open-label sessions of MDMA-assisted therapy reduce PTSD symptoms? Participants will receive three non-drug preparatory sessions followed by two sessions of MDMA-assisted therapy. Each MDMA-assisted therapy session is followed by three non-drug integrative therapy sessions.