Developmental pathways from childhood conduct problems to early adult depression: findings from the ALSPAC cohort

BACKGROUND Pathways from early-life conduct problems to young adult depression remain poorly understood. AIMS To test developmental pathways from early-life conduct problems to depression at age 18. METHOD Data (n = 3542) came from the Avon Longitudinal Study of Parents and Children (ALSPAC). Previously derived conduct problem trajectories (ages 4-13 years) were used to examine associations with depression from ages 10 to 18 years, and the role of early childhood factors as potential confounders. RESULTS Over 43% of young adults with depression in the ALSPAC cohort had a history of child or adolescent conduct problems, yielding a population attributable fraction of 0.15 (95% CI 0.08-0.22). The association between conduct problems and depression at age 18 was considerable even after adjusting for prior depression (odds ratio 1.55, 95% CI 1.24-1.94). Early-onset persistent conduct problems carried the highest risk for later depression. Irritability characterised depression for those with a history of conduct problems. CONCLUSIONS Early-life conduct problems are robustly associated with later depressive disorder and may be useful targets for early intervention.