The study aimed to assess the prevalence of ADHD in children aged 9-10 using a national dataset and analyze its comorbidities by applying various operational definitions.
Findings revealed that the prevalence of ADHD was approximately 3.5%, with a significant proportion of those diagnosed (70%) having additional psychiatric disorders like anxiety or disruptive behavior issues.
Children with a higher genetic risk (top decile of polygenic load) were 63% more likely to have ADHD, suggesting that stringent definitions of ADHD can highlight important genetic and cognitive relationships.