Adverse long-term effects of criminal legal system involvement on mental health in adulthood among a longitudinal cohort of youth in the USA

Background Despite an established association of criminal legal system (CLS) involvement with poor mental health, it has been challenging to estimate a long-term causal effect among youth. This study examined the effects of CLS involvement on mental health outcomes among youth in the USA over 10 years. Methods We used data from 5611 youth from the National Longitudinal Survey of Youth 1997 (2000–2010). Using the parametric g-formula, we estimated the risks of (1) depressive symptoms (defined by the Mental Health Inventory 5-item version) and (2) self-reported emotional, mental health or psychiatric problems at the end of the study, adjusted for confounding. To quantify the effect of CLS involvement, we calculated differences in the risks under the natural course of CLS involvement vs under two interventions: (1) removing arrests and incarcerations (‘no CLS involvement’) and (2) removing incarcerations only, with 95% CI derived from 300 bootstrap samples. Results The end-of-follow-up risk was 9.5% for both depressive symptoms and mental health problems under the natural course of CLS involvement. The ‘no CLS involvement’ intervention was estimated to lower the risks for depressive symptoms and mental health problems by 0.4 (95% CI −0.8 to −0.04) and 0.6 (95% CI −1.0 to −0.3) percentage points, respectively. The estimates for ‘no incarceration’ did not provide evidence of an effect. Conclusion Our findings support the hypothesis that CLS involvement, especially arrests, contributes to poor mental health among youth in adulthood and reaffirms that CLS involvement is a social determinant of mental health in this population.