A correlation has been shown to exist between parent usage and increased adolescent substance usage. The parental attitude toward illicit substance use has been positively correlated with adolescent substance use. Once the adolescent starts using illicit drugs, the influence of parents decreases, and the peer influence increases. The research provides further support to Kandel's theory of stages of substance use. In addition, it provides support to the theory that adolescent substance usage is learned, in part, by modeling and imitation. The results are not as conclusive in predicting personality characteristics of the adolescent and parental influence that predate adolescent substance abuse. (Publisher abstract)