UCLA

OBJECTIVE. Our goal was to examine substance-use initiation in healthy adolescents and in adolescents who have been diagnosed with attention-deficit/hyperactivity disorder. METHODS. Seventy-eight adolescents (28 healthy and 50 with attention-deficit/hyperactivity disorder) participated in an ongoing longitudinal study of predictors of substance use. The substances most commonly reported were tobacco, alcohol, and marijuana. Aggression, conduct problems, hyperactivity, impulsivity, inattention, anxiety/depression, social difficulties, and somatic complaints were assessed at study entry and tested as predictors for later substance use. RESULTS. With an average of 4 years into the study, 37 adolescents had not used any substances, 41 had experimented with at least 1 substance, and 29 experimented with > 1 substance. Psychiatric diagnoses (attention-deficit/hyperactivity disorder, attention-deficit/hyperactivity disorder and conduct disorder, and attention-deficit/hyperactivity disorder and depression/anxiety) did not influence reports of substance use. Distinct behavioral measures collected at study entry predicted use of different substances. In a multivariate analysis, aggression had the greatest association with tobacco smoking and marijuana use. Impulsivity was associated with alcohol use. Severity of drug exposure, indexed by the number of substances used, was predicted by aggression. CONCLUSIONS. This 4-year longitudinal study captured the onset of substance use, not abuse. Behavioral predictors differed with the type of substance used. These behavioral characteristics may raise suspicion among pediatricians for enhanced risk for substance-use initiation.