In this study, people will be undergoing brain scans with functional magnetic imaging (fMRI) while they perform an emotional regulation task that involves observing either neutral images or images known to induce negative emotions, with instructions either to view passively or attempt to reduce the negative affect associated with the images. Resting state brain scans (with no explicit task) will also be acquired. Heart rate variability will be measured during these resting state scans. While in the scanner, subjects will also listen to prerecorded audio scripts about life stresses for themselves and for another person with instructions to practice compassion for themselves or for others. In yet another task, they will respond to pictures known to produce positive and negative emotions and perform an attention related task. The scans will take place once before and at least once after undergoing sessions of methylenedioxymethamphetamine (MDMA) assisted psychotherapy. Brain scans will happen three times: an initial scan before placebo or MDMA-assisted psychotherapy, a second scan after either two placebo or two MDMA sessions (depending on whether the subject was in the placebo or MDMA group), and one final scan after the conclusion of three active MDMA sessions.