Living and coping with HIV-1 infection is a challenge for the symptomatic patient and the family because of the lethality of the infection, the chronic nature of illness episodes, disruption of normal social roles, and the potential for social discrimination. For the asymptomatic seropositive person, the long latency period translates the threat of developing AIDS into a chronic stressor commonly leading to psychological distress. For those who are not infected with HIV but who perceive themselves at risk because of their high risk behavior, the threat of AIDS may be viewed as a profound stressor. Although the importance of psychosocial research was recognized early on in the AIDS epidemic, important psychosocial issues remain, including understanding differential rates of progression to AIDS, the role of social support in physical and mental functioning and their interrelationships. The special role of the family as a source of coping or as a stressor has more recently become seen as an important component of the care process and in disease progression. This study seeks to elucidate the role of families in HIV disease progression and for HIV prevention among injection drug users (IDUs). Over the last 5 years we have recruited 2,921 IDUs screened for HIV in the ALIVE Study in Baltimore, with 703 seropositives identified. Of these, 630 positives were enrolled for follow-up; another 1524 negatives returned at least once for serologic rescreen, and 160 seroconverters have been identified and enrolled in follow-up. Return rates for the follow-up clinic have consistently exceeded 85% at each 6 month interval. In this study we will address issues of family and other sources of social support and coping, psychological distress, and HIV progression among IDUs in a 2-year longitudinal study. We will provide data on these issues which have not been collected by our group, and we will integrate this information with biological, behavioral and psychosocial factors associated with HIV illness. We will also interview family, members to determine the influence of HIV on family dynamics, composition and functioning. Multivariate analysis incorporating interaction terms for extent of immunosuppression and family support will be used to understand psychological distress, decline in physical health status, and behavior change in IDUs as a function of family and other social support, as well as coping.