Longitudinal substance use and adult adjustment.

Relationships among long-term use patterns of tobacco, alcohol, marijuana, and other substances from late childhood to young adulthood and adjustment in young adulthood were examined. The sample consisted of 133 participants from the New York Longitudinal Study. Cluster analysis revealed four groups of individuals for each of the substance categories, as well as for use of multiple substances, over the five points of measurement. Cluster membership was related to adjustment differences in young adulthood. Results from a series of ANOVAs indicated that individuals consistently using the highest amounts of alcohol and other drugs exhibited the highest levels of psychiatric symptoms. Follow-up analyses indicated that negative emotional-behavioral states in middle childhood precede problematic patterns of substance use. Implications for intervention in childhood are discussed.