Study Comparing Two Versus Three Active MDMA-assisted Sessions in U.S. Military Veterans With Chronic PTSD

The goal of this clinical trial is to learn if MDMA-assisted therapy is effective in U.S. military veterans with at least moderate chronic PTSD. The main question it aims to answer is: Are two versus three MDMA-assisted therapy sessions in an outpatient treatment clinic more effective? Researchers will compare two MDMA-assisted therapy sessions to three MDMA-assisted therapy sessions. Participants will undergo three non-drug preparatory sessions prior to their first MDMA-assisted therapy session. Each MDMA-assisted therapy session will be followed by three non-drug integrative therapy sessions.