From the Journal of Substance Abuse Treatment:
There is a high prevalence of alcohol use, abuse, and dependence in methadone maintenance treatment (MMT) programs. There have been reports that this may be a result of entry into methadone maintenance. Through a systematic review, this article attempts to determine whether alcohol consumption is affected during the course (from prior to treatment initiation to once on maintenance) of MMT. A literature search for publications addressing the issue of alcohol use while on MMT was conducted. Of 15 heterogeneous clinical studies that met inclusion criteria, three studies supported an increase in alcohol use, three supported a decrease in alcohol use, and nine supported no change in alcohol use. The studies varied in their methodology and in their definition of problematic alcohol use. This review found that alcohol use, although often problematic in methadone-using patients, likely does not change upon entering MMT. (emphasis added) We recommend routine screening and treatment for problematic alcohol use in patients on MMT.