Prevalence of psychiatric disorders in foster care adolescent populations

Children in foster care and institutional settings experience disproportionately high rates of mental health disorders, yet large-scale data on psychiatric comorbidities in this population remain limited.

To examine the prevalence and patterns of psychiatric diagnoses within one year of placement in foster care or institutional care, with attention to demographic disparities and comorbidity burden.

This retrospective cohort study used de-identified electronic health record data from the TriNetX network, identifying U.S. children placed in foster or institutional care between 2003 and 2023 via ICD-10-CM codes. The final sample included 95,764 children after exclusions. Demographic characteristics and psychiatric diagnoses were analyzed descriptively, and comorbidity patterns were assessed by co-occurrence of two or more disorders.

The mean age at placement was 6.62 years; 47,911 (50.02%) were male, 46,484 (48.57%) female, and 1369 (1.41%) of unknown gender. Black or African American children comprised 28,876 (30.16%) of the cohort, exceeding their proportion in the general U.S. child population. Within one year of placement, 53,627 (56%) had at least one psychiatric diagnosis, and 28,729 (30%) had two or more. Behavioral and emotional disorders were most prevalent (31,602; 33%), with attention-deficit/hyperactivity disorder affecting 20,110 (21%) and conduct disorder 7661 (8%). Anxiety disorders occurred in 23,941 (25%), including post-traumatic stress disorder in 11,492 (12%) and generalized anxiety disorder in 5746 (6%). Mood disorders affected 14,365 (15%), developmental disorders 13,407 (14%), and substance use disorders 5746 (6%), primarily nicotine dependence (2873; 3%) and cannabis use disorder (1915; 2%). Common co-occurrences included ADHD with anxiety disorders in 11,492 (12%) and PTSD with mood disorders in 7661 (8%).

Psychiatric morbidity is common and complex among children entering foster or institutional care, underscoring the need for early, trauma-informed, and culturally responsive mental health interventions. High co-occurrences rates and persistent racial disparities highlight the urgency of coordinated, equity-focused approaches to assessment and treatment in child welfare systems.