Objectives: To explore the relationship of epilepsy and criminal behavior.
Methods: Case series based on all criminal cases found "not guilty by reason of insanity" (NGRI) because of epilepsy in England and Wales between 1975 and 2001. Data were extracted from medico-legal reports held by the Mental Health Unit at the Home Office and the Department for Constitutional Affairs in London, UK.
Results: Thirteen cases were identified, accounting for 7.3% of all verdicts of NGRI. Charges included murder (1), attempted murder (1) assault (7), arson (2), abduction/kidnapping (3), and burglary (1). Of the defendants, 92.3% were male, 76.9% had neuropsychological impairments, 84.6%% had psychiatric comorbidity, 92.3% were unemployed at the time of the offence, and 69.2% had been convicted of criminal offences previously. Eight of 10 defendants treated with antiepileptic drugs were complying poorly with medication. A total of 61.5% offenses were committed in a state of alcohol intoxication. Psychotic symptoms may have been present when the offense was committed in 52.8% of cases. Over two-thirds of offenses probably occurred during the postictal period.
Conclusions: This case series suggests that it is exceptional for epileptic seizures to cause criminal acts or omissions. The relatively low standard of proof required means that some of cases found NGRI on account of epilepsy were not actually related to seizures. There were no definite examples of ictal criminal behavior. Most offenses related to seizures are likely to have occurred in the postictal phase.