Abstract
OBJECTIVE: To identify trajectories of substance use disorders (SUDs) in youth during the 12 years after detention and how gender, race/ethnicity, and age at baseline predict trajectories. METHOD: As part of the Northwestern Juvenile Project, a longitudinal study of 1,829 youth randomly sampled from detention in Chicago, Illinois from 1995 through 1998, participants were reinterviewed in the community or correctional facilities up to 9 times over 12 years. Independent interviewers assessed SUDs using the Diagnostic Interview Schedule for Children 2.3 (baseline) and the Diagnostic Interview Schedule IV (follow-ups). Primary outcome was a mutually exclusive 5-category typology of disorder: no SUD, alcohol alone, marijuana alone, comorbid alcohol and marijuana, or "other" illicit ("hard") drug. Trajectories were estimated using growth mixture models with a 3-category ordinal variable derived from the typology. RESULTS: During the 12-year follow-up, 19.6% of youth did not have an SUD. The remaining 81.4% were in 3 trajectory classes. Class 1 (24.5%), a bell-shaped trajectory, peaked 5 years after baseline when 42.7% had an SUD and 12.5% had comorbid or "other" illicit drug disorders. Class 2 (41.3%) had a higher prevalence of SUD at baseline, 73.8%. Although prevalence decreased over time, 23.5% had an SUD 12 years later. Class 3 (14.6%), the most serious and persistent trajectory, had the highest prevalence of comorbid or "other" illicit drug disorders-52.1% at baseline and 17.4% 12 years later. Males, Hispanics, non-Hispanic whites, and youth who were older at baseline (detention) had the worst outcomes. CONCLUSION: Gender, race/ethnicity, and age at detention predict trajectories of SUDs in delinquent youth. Findings provide an empirical basis for child psychiatry to address health disparities and improve prevention.