Role of drug-abuse treatment in limiting the spread of AIDS.

Drug-abuse treatment may have important direct and indirect effects on restricting the spread of infection with human immunodeficiency virus by decreasing the prevalence of intravenous drug use and by decreasing regular drug use that impairs the immune system. Drug-abuse treatment results in substantial declines in the use of heroin, cocaine, prescription psychotherapeutic drugs, and other drugs in the year after treatment. Declines are closely related to the length of time spent in treatment; treatment duration of greater than or equal to 6 months has a significant impact on drug use after treatment. The potential impact of drug-abuse treatment in combatting the AIDS epidemic is discussed.