Children with attention-deficit/hyperactivity disorder (ADHD) are at increased risk of learning difficulties. This association may reflect shared risk factors, ADHD symptoms hindering learning, or learning difficulties increasing ADHD symptoms. We aimed to map rates of co-occurrence among ADHD, dyslexia, dyscalculia, and reading comprehension difficulties and to investigate directional influences between ADHD symptoms and reading fluency, arithmetic, and reading comprehension. Reading fluency, arithmetic, and reading comprehension were assessed longitudinally in approximately 2,000 Finnish children across Grades 1 to 9 (ages 7–16).
Children with a learning difficulty were 1.14 to 1.76 times more likely to have ADHD, whereas children with one learning difficulty were 4.32 to 4.62 times more likely to have another.
Directionality between ADHD symptoms and academic skills was examined using random intercept cross-lagged panel models (RI-CLPMs) to separate stable traits from time-specific states.