Participants in this trial were randomly assigned to receive either bupropion or placebo for 6 months. Study visits lasting approximately 2 hours each occurred at Day 0, and at Months 4, 6, and 9; included in these visits were physical examination, testing for HIV and sexually transmitted disease (STD), depression screening, and an interview-administered questionnaire inquiring into sexual activity and drug use. Shorter study visits, lasting 15 - 30 minutes each occurred at Day 15, and Months 1, 2, 4, 5, and 7, and included depression screening and physical exam.