title: A four-year follow-up study of narcotic-dependent persons receiving methadone maintenance substitution therapy.
mesh_terms: D000328:Adult; D005260:Female; D006556:Heroin Dependence / Q000534:rehabilitation*; D006801:Humans; D008297:Male; D008691:Methadone / Q000627:therapeutic use*
chemical_list: D008691:Methadone