Epilepsy in children with attention-deficit/hyperactivity disorder.

Previous studies have suggested a higher incidence of symptoms of attention-deficit/hyperactivity disorder (ADHD) in children with epilepsy, but few have investigated epilepsy in children with ADHD. The objective here was to compare the incidence and characteristics of epilepsy among population-based, research identified cohorts of children with (n = 358) and without ADHD (n = 728), based on medical record review to age 20 years. Data abstracted included characteristics of seizures, testing, and treatment. Cases were 2.7 times more likely than controls to have epilepsy (95% CI = 0.94-7.76; P = 0.066), had earlier seizure onset (median age, 5.5 vs 15 years; P = 0.020), and exhibited a trend toward more frequent seizures (more than monthly, 63% vs 17%). Among children who met the research criteria for ADHD, those with epilepsy tended to be less likely to have received a clinical diagnosis of ADHD (63% vs 89%; P = 0.052) or to be treated with stimulants (50% vs 85%; P = 0.025). The findings suggest a strong trend toward a higher incidence of epilepsy among children with ADHD than among children without ADHD. Epilepsy in children with ADHD appears to be more severe than in those without. Finally, there appears to be a reluctance to diagnose and initiate treatment for ADHD in children with epilepsy.