Children's cognitive abilities play an important role throughout their academic career, but recent studies highlight the negative impacts of aggression, inattention, and impulsivity on academic success. These behaviors and traits are central to most externalizing (EXT) and neurodevelopmental (NDD) problems, which are substantially genetically influenced. We examined the mechanisms by which high levels of genetic predispositions to EXT and NDD problems associate with elevated mental health symptoms and subsequently lead to lower levels of academic achievement in two developmental periods (i.e., childhood and adolescence).

Analyses were performed on a subset of participants from the Generation R Study (N = 2,992) and the Avon Longitudinal Study of Parents and Children (ALSPAC) (N = 5,099). Using structural equation modeling, we simultaneously tested for indirect pathways between polygenic scores for externalizing and neurodevelopmental problems (PGS-EXT and PGS-NDD) and academic achievement (age 12 in the Generation R Study and age 16 in ALSPAC) via children's symptomatology for conduct, attention, social, and oppositional defiant problems reported by mothers during early childhood (Generation R Study) and from childhood to adolescence (ALSPAC study). Our models were adjusted for children's sex, exposure to adversity, cognitive abilities, early school achievement (only in ALSPAC), and genetic predisposition to educational attainment.

In both cohorts, we found that higher levels of PGS-NDD were associated with lower levels of academic achievement via higher attention problems. In adolescence only, we found that higher levels of PGS-NDD and PGS-EXT were associated with lower academic achievement via higher levels of conduct problems.

Genetic predispositions to EXT and NDD were indirectly associated with academic achievement beyond the PGS for educational attainment, highlighting the need for sustained efforts to support children with attention problems in educational settings and to intervene on conduct problems, particularly during adolescence.