People enrolled in the study can continue taking anti-anxiety medications, but cannot take any other psychiatric medications for the entire course of the study. They can take their usual pain control medications, but if they take more pain control medications than usual on the day of the MDMA-assisted session, they may have to delay or reschedule the session. People enrolled in this study will complete questionnaires about their anxiety and quality of life, and they will keep a daily diary where they write down how much anxiety and pain control medication they are using, and a daily record of the amount of pain they experience.