Effects of depression genetic risk and household socioeconomic status on emotional behavior and brain development in early adolescence.

The World Health Organization (WHO) ranks depression as the number one non-fatal contributor to the global burden of disease. Previous work finds that early intervention prior to onset leads to preferred outcomes. To examine depression prior to onset, risks are assessed in relation to depressive prodromal behavior and brain biomarkers. Research shows environmental and genetic risks both separately influence depression onset, but little research has examined their interaction. Thus, we examined whether the socioeconomic predictor of family income-to-needs ratio (INR) may have independent and/or interactive effects with an individual's depression polygenic risk score (D-PRS) on youth behavior and brain structure and function. We leveraged the U.S. based ABCD Study - an existing longitudinal dataset; this work examined ~8,000 subjects, 9-10 year-of-age at baseline to 11-12 year-of-age at 2-year follow-up. Historically, genetic analysis was conducted in European-like samples. Therefore, our work first assesses effects in youth with European-like genetic ancestry. Next, to improve generalizability, the same analyses were conducted in youths who are not European-like. Overall, D-PRS was associated with behavior and brain within the European-like youths, but less so in the not European-like sample. A potential moderating effect of INR on D-PRS was also seen for brain network connectivity, with further main effects of INR in youths from lower socioeconomic statuses. The findings from this project suggests behavior-brain biomarkers associated with socioeconomic status and depression risk vary by genetic ancestry, further highlighting the importance of precision-based medicine research in hopes of improving early detection and treatment of depression.