Interictal violence in epilepsy. Relationship to behavior and seizure variables.

Interictal violence among epileptic patients could result from factors other than epileptiform activity. We characterized 44 patients who presented for psychiatric evaluation because of violent behavior. Most violent acts consisted of verbal or minor physical aggression. Twenty (45%) of these patients met criteria for a schizophrenic disorder, and one committed murder during a paranoid schizophrenic relapse. In addition to schizophrenia, the violence patients had significantly more mental retardation when compared with 88 age- and sex-matched epileptic patients without prior violent behavior. However, violent and nonviolent patients did not differ on seizure variables such as type and frequency of seizures, auras, electroencephalographic changes, epilepsy age of onset, or anticonvulsant therapy. These findings suggest that interictal violence is associated more with psychopathology and mental retardation than with epileptiform activity or other seizure variables.