Abstract
This paper reviews the evidence for the effectiveness of methadone maintenance as used in the treatment of opioid dependence. Findings from randomized controlled trials and observational studies suggest that methadone maintenance reduces heroin use, crime, injection-related risk behaviours and premature mortality among people dependent on opioids. The research further suggests that two aspects of treatment are important in ensuring this effectiveness. Methadone treatment is more effective when higher doses (>50 mg) are employed and, overall, the evidence suggests that a treatment goal of successful maintenance on methadone rather than total abstinence is appropriate. The importance of ancillary services in treatment outcome is less clear and is the subject of current research and debate.