Special contribution: national survey of marijuana use and attitudes.
D000293:Adolescent; D000328:Adult; D000367:Age Factors; D001290:Attitude; D002188:Cannabis; D002648:Child; D004335:Drug and Narcotic Control; D006801:Humans; D008875:Middle Aged; D009790:Occupations; D011057:Politics; D019966:Substance-Related Disorders / Q000453:epidemiology*; D013997:Time Factors; D014481:United States