"MMT [methadone maintenance treatment] facilitates a process of gradual reduction in heroin use, reduction of syringe sharing and HIV risk, and reduction of criminal activities."
Source
Rosenbaum, et al., "Treatment as Harm Reduction, Defunding as Harm Maximization: The Case of Methadone Maintenance," Journal of Psychoactive Drugs, 28: 241-249 (1996).