This study identified the impact of heroin compared to other drugs of abuse on the social, nutritional and health status of addicts, and assessed their response to detoxification. A total of 243 heroin addicts and 66 non-heroin addicts were included in the study. Heroin and non-heroin addiction had similar impact on social and nutritional status, but heroin addicts were seven times more likely to develop hepatitis B or C infection. Non-heroin addicts were more prone to develop depressed cellular immunity. The number of relapses was twice as high for heroin addicts who experienced more unpleasant symptoms during therapy. Active interventions to prevent and control addiction are needed regardless of the type of drug abused.