Adolescent Overdose Mortality and Child Protection System Involvement: Evidence from a California Birth Cohort, 2000-2005.

Objectives. To examine overdose mortality across 4 levels of child protection system (CPS) involvement during childhood. Methods. Using integrated vital birth, death, and CPS records of California births (2000-2005) followed through 2024 (n = 3 208 771), we identified 747 adolescent overdose decedents and matched each to 4 comparison adolescents (n = 2988). We categorized CPS exposure as no contact, referral, substantiated referral, or foster care. Using conditional Poisson regression, we estimated overdose prevalence by CPS involvement level. Results. Overall, 69.9% of decedents had at least 1 CPS referral, compared with 34.6% of matched comparison adolescents. Any CPS history was associated with a 5-fold higher rate of overdose death (incidence rate ratio = 5.36; 95% confidence interval = 4.41, 6.51), with elevated rates observed across all levels of CPS involvement. Conclusions. CPS history was highly prevalent among adolescents who died from overdose, and regardless of level, may function as a meaningful marker of overdose vulnerability. Public Health Implications. Improved coordination between CPS and Medicaid-funded behavioral health services may facilitate earlier intervention for this high-risk population. (Am J Public Health. Published online ahead of print September 24, 2026:e1-e4. https://doi.org/10.2105/AJPH.2026.308762).