The natural history of drug abuse.
D000328:Adult; D000367:Age Factors; D006556:Heroin Dependence; D006801:Humans; D008297:Male; D002189:Marijuana Abuse; D009042:Motivation; D012940:Social Problems; D019966:Substance-Related Disorders / Q000209:etiology / Q000523:psychology*; D013997:Time Factors; D014728:Veterans