Trajectories of Adolescent Multi-System Involvement and Mental Health Outcomes at 18

Background: Research consistently shows that system-involved adolescents face elevated risks of behavioral and mental health problems. Prior studies suggest that involvement in one system often overlaps with contact in others, and that such overlap can reflect cumulative disadvantages and chronic instability. However, most research examines systems in isolation or relies on static “ever/never” indicators of contact, such as ever/never involvement, which obscures the timing and movement across systems. There is limited research about the distinct trajectories of multi-system involvement that unfold across adolescence and how these patterns may shape outcomes at 18, a key transition point from minor to legal adult. This study addresses this gap by analyzing trajectories of child welfare, foster care, juvenile justice, and Medicaid involvement from ages 12 to 17, and determines how these trajectories shape mental health and substance use outcomes at age 18.

Methods: We analyzed a sample of 9,799 adolescents drawn from the Pennsylvania CWS administrative records who were born in 2001 and had at least one referral between 2013 and 2019. By linking these records with juvenile justice and Medicaid data, we conducted sequence analysis to characterize patterns of involvement across systems. We grouped adolescents into distinct trajectory clusters and employed logistic regression to examine associations between cluster membership and Medicaid claims for mood or substance use disorders at age 18.

Results: Sequence analysis identified six distinct trajectories of multi-system involvement between ages 12 and 17: Escalating mixed-system involvement (14.8%), justice-centered crossover (4.4%), CWS or Medicaid surge (7.5%), low involvement (39.0%), moderate Medicaid or CWS involvement (20.1%), and persistent Medicaid involvement (14.2%). Using the low-involvement cluster as the reference group, persistent Medicaid involvement was associated with higher odds of mood disorders at age 18. For substance use disorders at age 18, youth in the justice-centered crossover cluster faced the highest odds, followed by those in the escalating mixed-system cluster.

Conclusions and Implications: This study highlights that multi-system involvement across adolescence is not a uniform experience but unfolds through distinct trajectories that carry varying risks. Trajectories marked by juvenile justice involvement and broader system complexity are most strongly associated with substance use disorders. These patterns underscore the importance of moving beyond static indicators of system contact to capture the timing, duration, and overlap of system contact.