Depression with and without Comorbid Substance Dependence in a Child Welfare Sample of Young Adults.

The objective of this study was to estimate the prevalence of depression with and without substance dependence and examine the effect of risk factors on subsequent disorders among a cohort of young adults in the US Child Welfare System (CWS). We used longitudinal data for 834 young adults age 18-21 from the National Survey of Child and Adolescent Well-being. Depressive symptoms and substance use were measured at baseline (age 11-15); diagnoses of depression and substance dependence were identified at the last wave of data collection (age 18-21). Likelihood of subsequent depression with or without substance dependence was three times higher for those with clinically significant depressive symptoms at baseline. Frequent use of substances at baseline significantly increased the likelihood of subsequent depression with comorbid substance dependence compared to depression alone. These results support screening youth in the CWS at younger ages for both depressive symptoms and substance use with the hope that these disorders can be detected earlier.