title: Issues in the assessment of multiple drug use among drug treatment clients.
mesh_terms: D000437:Alcoholism / Q000175:diagnosis; D003042:Cocaine; D004812:Epidemiologic Methods; D005500:Follow-Up Studies; D006801:Humans; D002189:Marijuana Abuse / Q000175:diagnosis; D009293:Opioid-Related Disorders / Q000175:diagnosis; D011446:Prospective Studies; D019966:Substance-Related Disorders / Q000175:diagnosis* / Q000453:epidemiology / Q000628:therapy
chemical_list: D003042:Cocaine