Studying social reactions to drug self-administration.
D000428:Alcohol Drinking; D002188:Cannabis; D006556:Heroin Dependence / Q000523:psychology; D006801:Humans; D010919:Placebos; D012107:Research Design; D012646:Self Administration; D012919:Social Behavior; D019966:Substance-Related Disorders / Q000523:psychology*; D013997:Time Factors
D010919:Placebos