The effects of adolescent depression and attention-deficit/hyperactivity disorder on educational attainment in adulthood.

Early-onset mental disorders, particularly depression and attention-deficit/hyperactivity disorder (ADHD), are a growing concern among U.S. adolescents. Previous research offers inconclusive findings on how these conditions affect educational attainment, and the pathways remain unclear. This paper estimates the causal effects of adolescent depression and ADHD on adult educational attainment using data from the National Longitudinal Study of Adolescent to Adult Health (Add Health). To address unobservable confounders, measurement errors, and reverse causality, we employ polygenetic scores (PGSs) and friend suicide attempts as instruments. We find that a one standard deviation increase in ADHD score reduces years of education by 1.3 and the predicted probability of achieving a bachelor's degree by 24.6 percentage points. Depression shows no significant impact on educational attainment. We further identify that the negative impact of ADHD on educational outcomes is primarily attributed to diminished academic performance and impaired self-regulation. School-based interventions and parent management training are potential solutions to mitigate these effects.