Which School Experiences Matter? A Co-Twin Analysis Linking Childhood ADHD to Adult Educational Attainment

This study examines whether school functioning (academic performance and motivation) and social/behavioral functioning (suspensions and peer affiliations) in high school mediate the association between childhood Attention-Deficit/Hyperactivity Disorder (ADHD) and adult educational attainment.

Participants were 3,762 twins (1,881 same-sex pairs; 52% female; 96% non-Hispanic White) from the population-based Minnesota Twin Family Study. Childhood ADHD symptoms were assessed via structured diagnostic interviews at intake (age 11 or 17, depending on cohort), mediators were assessed via teacher and self reports at age 17, and educational attainment was assessed in adulthood (mean age = 34.7 years). Mediation path models tested each indirect pathway, and co-twin comparisons were used to better isolate potential causal effects by controlling for familial confounding.

At the individual level, all tested indirect paths linking ADHD to educational attainment were significant. However, co-twin control analyses indicated that most associations attenuated when accounting for familial confounding. Only the indirect path through academic motivation persisted after co-twin control, such that twins with greater academic motivation relative to their co-twin also had greater educational attainment, consistent with a potential causal effect. Academic performance and social/behavioral mediators did not show significant mediation after accounting for shared genetic and environmental factors.

Academic motivation emerges as the most robust mediator linking childhood ADHD to reduced educational attainment. Interventions targeting student engagement, self-efficacy, and connection to school may improve long-term educational outcomes in youth with ADHD.