Behavioral and related disorders are frequently reported in association with childhood epilepsy but the reasons for this are unclear. In a long-term prospective, community-based study of newly-diagnosed childhood epilepsy, behavioral assessments (Child Behavior Checklist) were performed in children 8 to 9 years after the initial diagnosis of epilepsy to determine the impact of remission and medication status on behavioral problems. Children with epilepsy were also compared with sibling controls. A total of 226 children (108 females, 118 males; mean age 13y 1mo [SD 2y 8mo], range 8-17y) with idiopathic or cryptogenic epilepsy were included in the analyses. One hundred and twenty-eight matched pairs were included in analyses of case-sibling differences. Lack of remission and current medication use were associated with worse behavioral problem and competency scores. Lack of remission generally had a greater effect than medication use, except for attention problems; medication status had the more deleterious effect (p<0.001). Children with epilepsy had significantly worse behavioral problems and competency scores relative to sibling controls. Even in pairs in which the patient was seizure-free and off medication, significant case-sibling differences persisted for most scales (p=0.05 to p=0.001). Lack of remission and continued use of antiepileptic drugs have a negative influence on behavioral problems in children with epilepsy but do not fully explain the worse scores relative to siblings. This suggests an independent effect associated with the epilepsy itself.Studies conducted in the 1970s demonstrated high rates of behavioral disturbances associated with symptomatic or severely uncontrolled epilepsy. 1,2 More recent studies of pediatric epilepsy have focused on cryptogenic and idiopathic epilepsy. [3][4][5][6][7][8][9][10][11] These studies have demonstrated an unusually high occurrence of a wide range of social, cognitive, behavioral, and psychiatric difficulties during the active phase of the disorder. It is not fully clear, however, whether adverse associations with epilepsy are seen just in association with ongoing seizures and current use of antiepileptic drugs (AEDs). Some studies found that poorer than expected social and educational outcomes occur even in individuals with excellent seizure control who are no longer on medication. [12][13][14] The independent contributions of seizure control, medication, and epilepsy itself on behavior or related outcomes have not been clearly distinguished. We have addressed this issue in the context of a long-term, prospective, community-based study of children initially recruited when first diagnosed with epilepsy. The focus of the current analyses was to: (1) assess the relative contributions of type of epilepsy, seizure control, and medication status to behavioral problems and to social competencies in children with idiopathic or cryptogenic epilepsy; (2) determine whether children with epilepsy had higher levels of behavioral symptomatology and lower social competenci...