Polydrug abuse and the maturing national drug abuse data base.
D000293:Adolescent; D000328:Adult; D002188:Cannabis; D005260:Female; D006801:Humans; D008297:Male; D012306:Risk; D013223:Statistics as Topic; D019966:Substance-Related Disorders / Q000453:epidemiology*; D014481:United States; D014492:United States Public Health Service