Nine models for the etiology of drug abuse have been examined. Problem behavior theory, domain theory, and Flay's developmental model suggest that drug use is a functional behavior for adolescents, and that prevention efforts should address this functionality and provide alternative behaviors for drug use rather than simply trying to suppress the underlying need or reason for use. These positions, together with the stages of drug use and stages of antisocial behavior models, place drug use in a developmental context, suggesting that the factors that influence drug use evolve as the child matures through adolescence, and that the developmental period of the adolescent should be considered in any prevention effort. They also suggest that drug use is common for many adolescents in today's culture. There is general support among the models to consider drug use as a part of a larger constellation of behaviors, whether labeled problem behaviors, antisocial behaviors, or by another name. This suggests that prevention programs must treat drug use in its behavioral context as well as its developmental and functional context. Finally, there is strong support for social-environmental factors such as modelling, availability of drugs, and social supports in the development of drug use. Though the various models often use different terminology, there are remarkable similarities in their implications for prevention efforts.