This entry describes the role of social support in HIV prevention and care primarily among gay, bisexual, and other men who have sex with men (GBMSM), which are among the populations most affected by the HIV/AIDS epidemic in the [Page 527]United States. A brief review of social network theory to explain the different types and sources of social support is followed by a discussion of how social support benefits physical and mental health. The entry then describes the importance of social support in relation to HIV prevention and vulnerability to HIV infection. Next, there is a discussion on the importance of social support in relation to the health of people living with HIV/AIDS (PLWHA). Given the vast body of literature on the role of social ...