Do inattention and hyperactivity symptoms equal scholastic impairment? evidence from three European cohorts

Background: Attention Deficit/Hyperactivity Disorder (ADHD) affects many children, adolescents, and adults and is associated with a number of impairments. Poor academic performance is related to ADHD in clinical samples. However, it is unclear to what extent core ADHD symptoms and scholastic impairment are related in non-referred school-aged children. Methods: Data come from three population-based cohorts from Sweden, Denmark, and Finland, which are part of the Nordic Network on ADHD. The combined sample size was 13,087 children who were studied at ages 7-8 or 10-12 years. Teachers rated children on inattention and hyperactivity symptoms and reported children's scholastic performance on basic skills. Results: There was a significant association in all cohorts between core ADHD symptoms and scholastic impairment in reading, writing, and mathematics. Particularly, inattention was related to a two to tenfold increase in scholastic impairment. Prevalence of hyperactivity symptoms was similar across the three cohorts, but inattention was lowest among children from the Finnish cohort, after stratification on living conditions. Conclusion: These results extend previous reports of scholastic impairment among children with clinically diagnosed ADHD to non-referred population samples from three European countries. Surveillance policies should be implemented in school systems to catch children in need of behavioral or scholastic support early.