Surrounded by genes: Parental genetic effects on children’s mental health

Internalizing problems are common in youth and linked to adverse long-term outcomes. While both children’s own genetic variants (direct genetic effects) and the genetics of their parents (indirect genetic effects) contribute, the direct and indirect genetic traits involved remain unclear. Here, we applied multi-polygenic score models using elastic net regression to identify key genetic predictors of depressive and anxiety symptoms at ages 8 and 14 in 9,314 parent-child trios from the Norwegian Mother, Father, and Child Cohort Study. We included 60 PGSs of children and parents. Predictive accuracy improved with age, with models explaining up to 2.4% of the variance in depressive symptoms and 1.1% in anxiety. Key predictors included child ADHD and wellbeing spectrum PGSs, as well as parental PGSs for smoking, BMI, and risky behaviors. These findings underscore the value of incorporating diverse parental genetic traits to understand intergenerational risk transmission and developmental changes in child mental health.