Marijuana and cocaine effect expectancies and drug use patterns.

Self-reports from 704 college students were content analyzed and used to develop the Marijuana Effect Expectancy Questionnaire and Cocaine Effect Expectancy Questionnaire. Responses were examined using exploratory and confirmatory principle components analysis. Six marijuana expectancies (34.6% of variance) were identified: (a) cognitive and behavioral impairment, (b) relaxation and tension reduction, (c) social and sexual facilitation, (d) perceptual and cognitive enhancement, (e) global negative effects, and (f) craving and physical effects. Five cocaine expectancies (32.5% of variance) consisted of (a) global positive effects, (b) global negative effects, (c) generalized arousal, (d) anxiety, and (e) relaxation and tension reduction. Drug effect expectancies distinguished between patterns of nonuse and varying degrees of use of these two drugs.