The study will use a within-subject design with three sessions: i) MDMA and conversation with Person A, ii) placebo and conversation with Person B, iii) test session (online) assessing preference for Persons A and B. The MDMA dose will be 100 mg, administered under double blind conditions. The conversation will consist of a 45 min dialog between the participant and the partner, a person trained to engage in conversation for this purpose. The dyad will be provided with topics to discuss, at their own pace. The order of administration of drug and placebo will be counterbalanced, and the partners will be same-sex and varied across sessions. The primary outcome measures will be feelings of closeness and connection at the end of the two drug sessions, at the online test session and follow-up. After study completion, participants will be fully informed about the study.
