Genetic risks for depression and educational achievement in adolescence

Mental health problems, including depressive disorders, show strong and robust associations with labour market attainment and other stratification outcomes, but underlying processes remain unclear. We use a genetically informed design to examine associations between genetic liability to major depressive disorder and ninth-grade educational achievement. Using nearly 38,000 parent-child trios from the Norwegian Mother and Child Cohort Study linked to test scores from administrative registers, we estimate direct effects of adolescents’ depression polygenic scores (PGS) and indirect effects of parental depression PGSs (sometimes described as “genetic nurture”), controlling for adolescents and parental educational attainment PGSs. In our baseline specification, a 1-SD increase in the child’s depression PGS predicts a modest 0.05 SD decline in test scores, but this association attenuates after adjusting for the child’s education PGS and becomes effectively zero when parental depression and education PGSs are included. Maternal and paternal depression PGSs show small negative associations with child achievement. Mediation analyses suggest these operate largely via parental education and income. We conclude that adolescents’ PGS for depression has, at most, a very small association with educational achievement in Norway, which is characterized by low inequality, inclusive education, and accessible high-quality health care.