P3 in young boys as a predictor of adolescent substance use.

Event-related potentials were recorded during a visual, continuous performance task from 36 boys before use of alcohol or other drugs began. The boys were sons of 13 recovering alcoholics who themselves had a family history of alcoholism, 11 nonalcoholics with a family history of alcoholism, and 12 nonalcoholics with no family history of alcoholism. Four years after electrophysiological assessment, a behavioral questionnaire was administered (mean age = 16.1 years). A Substance Use score was derived from reported use of alcohol and other drugs, and from highly correlated delinquent behavior scores. P3s of lowest amplitude were associated with the highest adolescent Substance Use. The combination of reduced amplitude and prolonged latency of both target and nontarget P3 significantly predicted adolescent Substance Use scores after correction for subjects' age. Although this is the first electrophysiological predictor of adolescent substance use we are aware of, the effect was small, indicating the utility of P3 as a vulnerability marker for substance abuse disorders is likely to depend on its joint use with other measures.