Methadone maintenance therapy (MMT) is more effective than non-opioid replacement therapies for treating opioid dependence, according to a Cochrane review. The review analyzed six randomized controlled trials involving 954 participants. MMT significantly improved retention in treatment (RR=3.05, 95%CI: 1.75-5.35) and reduced heroin use (RR=0.32, 95%CI: 0.23-0.44). However, it did not show a statistically significant effect on criminal activity (RR=0.39, 95%CI: 0.12-1.25) or mortality. MMT was found to be more effective than detoxification, drug-free rehabilitation, and placebo treatments. The review highlights that MMT is a well-researched treatment that helps patients stay in treatment and reduces heroin use. While MMT does not significantly reduce criminal activity or mortality, it remains an effective intervention for opioid dependence. The study emphasizes the importance of methadone's pharmacological properties and the role of ancillary services in enhancing treatment outcomes. The review also notes that methadone maintenance treatment is supported by observational studies and has been shown to reduce HIV transmission by decreasing needle sharing. Despite some limitations in the evidence, MMT is recommended as a maintenance treatment for opioid dependence.Methadone maintenance therapy (MMT) is more effective than non-opioid replacement therapies for treating opioid dependence, according to a Cochrane review. The review analyzed six randomized controlled trials involving 954 participants. MMT significantly improved retention in treatment (RR=3.05, 95%CI: 1.75-5.35) and reduced heroin use (RR=0.32, 95%CI: 0.23-0.44). However, it did not show a statistically significant effect on criminal activity (RR=0.39, 95%CI: 0.12-1.25) or mortality. MMT was found to be more effective than detoxification, drug-free rehabilitation, and placebo treatments. The review highlights that MMT is a well-researched treatment that helps patients stay in treatment and reduces heroin use. While MMT does not significantly reduce criminal activity or mortality, it remains an effective intervention for opioid dependence. The study emphasizes the importance of methadone's pharmacological properties and the role of ancillary services in enhancing treatment outcomes. The review also notes that methadone maintenance treatment is supported by observational studies and has been shown to reduce HIV transmission by decreasing needle sharing. Despite some limitations in the evidence, MMT is recommended as a maintenance treatment for opioid dependence.