Genotypic and Socioeconomic Risks for Depressive Symptoms in Two U.S. Cohorts Spanning Early to Older Adulthood

Genome-wide association studies have identified specific genetic variants associated with depression and depressive symptoms, but the developmental pathways that convey genetic risk remain poorly understood. Using data from the National Longitudinal Study of Adolescent Health (N = 5,690), we found that the association between genetic risk for depressive symptoms and increases in depressive symptoms across 14 years from early adolescence to adulthood was partially mediated by four socioeconomic resource variables assessed in adulthood: educational attainment, total assets, debt, and access to health insurance. In a preregistered and confirmatory replication using data from the Wisconsin Longitudinal Study (WLS; N = 8,964), we found evidence that the genetic risk for depression symptoms change across late mid-life was partially mediated by the four socioeconomic resource variables. Across a series of within-family sibling-difference analyses, however, we found no evidence in support of direct genetic effects on the putative environmental mediators. The results presented here highlight the need to explore between- and within-family model specifications for a more complete understanding of gene-environment pathways to psychiatric disease.