ADHD and epilepsy in childhood

Attention-deficit-hyperactivity disorder (ADHD) has been associated with childhood epilepsy; prevalence figures have ranged from 8 to 77%, depending on the sample studied and the criteria used for diagnosis. In the general population the prevalence of ADHD is approximately 5%, with the majority of affected children having ADHD combined type. As part of a larger study of behavioral problems in children with epilepsy, we assessed 175 children (90 males, 85 females; age range 9 to 14 years, mean age was 11 years 10 months, SD 1 year 8 months) for evidence of ADHD. The children had at least a 6-month history of epilepsy. The primary caregiver completed both the Child Behavior Checklist (CECL) and the Child Symptom Inventory-4 (CSI) or Adolescent Symptom Inventory-4 (ASI). On the CBCL, the mean attention problem T score was 64.6 (SD 10.5) for adolescents and 67.9 (SD 11.6) for children. On the CSI or ASI, 20 of 175 children met DSM-IV criteria for ADHD combined type; 42 of 175 had ADHD predominantly inattentive type; and 4 of 175 met criteria for ADHD predominantly hyperactive-impulsive type. There were significant correlations between the CBCL attention score and inattention (r=0.68) and hyperactivity-impulsivity (r=0.59). Sex, seizure type, and focus of seizure discharge were not predictors of symptoms of ADHD. Children with epilepsy are at risk for symptoms of ADHD. They differ from other samples of children with ADHD by the higher proportion of children with ADHD predominantly inattentive type and by an equal male: female ratio.