Research Brief: Criminal Legal System Involvement Before Age 18 and Seasonal Patterns of Depression and Anxiety During Adulthood

Article: Silver, Ian A., Nur, Alexandra V., and Faria, Kaylee D. 2026. “Seasonal Mental Health Symptoms Amongst Former Criminal Legal System‐Involved Adolescents.” Journal of Adolescence, 2026; 1–11. https://doi.org/10.1002/jad.70200

1. Background (PDF)

Individuals involved in the criminal legal system (CLS) before age 18 (arrest, incarceration in juvenile facility, incarceration in adult facility) face elevated rates of depression, anxiety, and other mental health conditions that persist into adulthood. These outcomes are expected to be produced by increased exposure to Adverse Childhood Experiences (ACE) and the collateral social/behavioral consequences of CLS involvement (e.g., employment, reduced health care access). Despite research suggesting that adolescent CLS involvement increases negative adulthood mental health symptoms, the magnitude of this relationship varies substantially across studies. Some research finds strong effects when comparing between CLS-involved youth and across CLS-involved youth and youth not involved in the CLS, while other studies report modest or null differences.

The inconsistent effects suggests that other factors may influence the observed relationship. One such factor might be the season in which mental health symptoms are assessed. Prior research demonstrates that symptoms of depression and anxiety fluctuate with seasonal changes in light cycles, temperature, and humidity, and that offending and detention patterns also vary by season. Guided by the existing literature, the current study asked: Does the season in which a mental health assessment is administered moderate the association between CLS involvement before 18 and adult symptoms of depression and anxiety?

2. Results

Using the National Longitudinal Survey of Youth 1997 (NLSY97) and a quasi-experimental analytical strategy, the study produced several key findings.

First, individuals with CLS involvement before age 18 had more severe symptoms of depression and anxiety during adulthood regardless of season, with more severe CLS involvement (arrest, incarceration in a juvenile facility, incarceration in an adult facility) associated with more symptoms of depression and anxiety.

Second, the season in which mental health was assessed moderated the effects of CLS involvement on depression and anxiety. For the general population, symptoms tended to be higher in fall and winter and lower in spring and summer. However, for youth incarcerated in juvenile or adult facilities before 18, symptoms were predicted to be higher in the summer and lower in the spring. Notably, youth incarcerated in adult facilities before 18 had lower predicted symptoms than the no-contact group in the spring, but higher symptoms in the winter, summer, and fall. The largest between-group differences were observed in the winter and summer and the smallest in the fall (See Figure 1).

Together, these findings indicate that CLS involvement before age 18 is associated with adulthood mental health symptoms, but the magnitude of these effects depends, in part, on the season in which symptoms are measured. Failing to account for seasonality may lead researchers and practitioners to over- or under-estimate the mental health needs of formerly CLS-involved youth.

3. Implications

These findings have implications for the mental health services provided to formerly CLS-involved youth. Practitioners administering services such as cognitive behavioral therapy should account for seasonal variation in symptom expression, recognizing that formerly CLS-involved youth may experience seasonal symptoms of depression and anxiety in a pattern distinct from the general population. Moreover, screening and diagnostic protocols for formerly CLS-involved youth should be administered regularly to account for changes in symptomology over time and throughout the year.

For CLS practitioners, these findings suggest that behavioral and mental health interventions that target post-CLS involvement symptomology should be developed and implemented, focusing on all youth that come into contact with the CLS. This form of intervention could help prepare youth to navigate the symptoms of depression and anxiety during adulthood, and emphasize the importance of seeking treatment when symptoms arise or reaching out preemptively for support before symptoms worsen during seasonal cycles. Future researcher on mental health amongst CLS-involved adolescents should consider developing study designs that account for the potential under- or over-reporting of symptoms during certain seasons, as failing to do so may bias effect size estimates. Future longitudinal studies should measure mental health at more frequent intervals and across seasons to improve precision.

4. Data and Methods

This study used data from the NLSY97, a nationally representative U.S. birth cohort of 8,961 individuals born between 1980 and 1984 and followed from 1997 to 2021, yielding 53,766 person-year observations across six interview waves (2004–2017). Participants were classified into four mutually exclusive CLS groups: no contact before 18, arrested only, incarcerated in a juvenile facility, and incarcerated in an adult facility. The primary outcome was symptoms of depression and anxiety measured using the Five-item Mental Health Inventory (MHI-5), and season of interview was categorized as winter, spring, summer, or fall.

Multi-group average treatment effect inverse probability weights for the CLS groups and seasons were estimated using gradient boosted propensity scores (TWANG) and applied in lognormal random intercept models predicting MHI-5 scores. Marginal predictions were evaluated using ANOVA and Tukey post hoc analyses. Missing data were handled with multiple imputation using a random forest estimator.

5. Conclusion

This study demonstrated that CLS involvement before age 18 is associated with increased symptoms of depression and anxiety during adulthood, but the magnitude of these effects varies by the season in which mental health is assessed. Youth incarcerated in juvenile and adult facilities exhibit seasonal symptom patterns that diverge from the general population, with the highest predicted symptoms occurring in the summer. These findings underscore the importance of accounting for seasonality in both research and clinical practice, and suggest that screening protocols for mental health symptoms should account for changes in symptomology over time and across the seasons.

Disclosure: This research brief was prepared by Microsoft Copilot and reviewed/edited by Ian A. Silver, Alexandra V. Nur, and Kaylee D. Faria.