A test of alternative explanations for the stage-like progression of adolescent substance use in four national samples.

Previous research has established that there is a stage-like phenomenon of adolescent substance use such that alcohol use usually precedes marijuana use, and marijuana use usually precedes hard drug use. The current study tests three potential explanations for this stage-like phenomenon using nonstandard log-linear models. In four national surveys dating from 1974 to 1988, the results were consistent for both sexes, ages ranging from 12 through 18, and for Whites, Blacks, and Hispanics. The results suggest that adolescents are more likely to use alcohol before marijuana, and marijuana before hard drugs because these substances are more widely used and are used at early ages. An additional reason for the stage-like phenomenon is that there is also a group of adolescents who are willing to try all types of substances and a second group who are unwilling to use any substances. Implications for future longitudinal studies are discussed.