mSTUDY is almost a 10-year research study being conducted at two sites in Los Angeles: The Los Angeles LGBT Center and the UCLA Vine Street Clinic. The purpose of the study is to understand how drug use affects the immune system of HIV-positive and HIV-negative men who have sex with men (MSM).

• Given that young, non-white MSM are at greatest risk of HIV infection in the U.S., the study will primarily enroll Latino and African American/Black men
• This project will look at if and how substance use affects the likelihood of infection in HIV- individuals and the progression of the virus in HIV+ individuals
• Participants that enroll will have their sexual behavior and social networks assessed through computer questionnaires and will provide various biological samples (blood, urine, saliva, hair/nails, etc.). Some of these will be collected to test for sexually transmitted infections (STIs) and substances, and the rest of which will be stored for use in future research
• Enrolled participants will come into the clinic for study visits every 6 months for 5+ years so we can continue this assessment over time