Methadone maintenance therapy (MMT) is the most widely used opioid agonist treatment for opioid dependence in the world. To determine the effectiveness of MMT compared with no treatment or treatment not including agonist therapy in patients with opioid dependence, Cochrane Collaboration researchers conducted a systematic review of clinical controlled trials done between 1969 and 2008. Eleven randomized controlled trials including, coincidentally, a quantity of 1969 patients and conducted in 5 different countries were identified. Outcome measures included treatment retention, mortality, opiate-positive drug test results, self-reported heroin use, and criminal activity. Study control groups included patients who received a double-blind placebo, those who received methadone for detoxification only, those who received counseling only, those wait-listed for treatment, and those receiving no treatment. The mean dose of methadone among patients in the MMT group was 60 mg or higher in most studies.

• MMT significantly increased retention in treatment, decreased morphine-positive drug tests, and decreased self-reported heroin use.
• MMT reduced mortality risk and criminal activity, but theses changes were not statistically significant.

Comments by Michael Levy, PhD
This meta-analysis demonstrates that, compared with no treatment or drug-free alternatives, MMT increases treatment retention and reduces heroin use in patients with opioid dependence. Although some treatment providers continue to discourage MMT, it is an effective treatment for heroin dependence, particularly for those patients who have not been able to achieve benefit through drug-free alternatives.