Is schizophrenia a risk factor for epilepsy or acute symptomatic seizures?

The precise prevalence of epilepsies and seizures in patients with schizophrenia remains unclear.

To assess the prevalence of epilepsy and of acute symptomatic seizures in schizophrenics, we conducted a survey in a urban sector of Marseilles that includes 56,910 inhabitants, among whom 1,154 had been treated for psychiatric disorders, including 460 for schizophrenia or paranoid disorder (PD) (DSM III-R 295 and 297.1, respectively; mean age, 41.9 years; range, 17-79 years; 215 men and 245 women).

All 460 patients were receiving long-term neuroleptic drug therapy, and 397 had been hospitalized at least once in the past year, whereas 63 were followed up as outpatients only. Seizures were present in the history of 12 patients: five had various forms of chronic epilepsy (four men, one woman; DSM III-R 295.1, one case; 295.3, two cases; 295.9, two cases), and three of these experienced seizures only after the onset of their psychiatric condition; five had acute symptomatic seizures (four men, one woman; 295.1, two cases; 295.3, 295.9, and 297.1, one case), and two had only pseudoepileptic events (both 295.3).

This survey shows that the prevalence of epilepsy and acute symptomatic seizures is comparatively low in patients with schizophrenia or PD (10.8 per thousand each, respectively), and that the prevalence of a history of seizures (21.7 per thousand in this study) is not particularly increased in this middle-aged population. In contrast to childhood-onset autistic disorders, schizophrenia or PD are not major risk factors for epilepsy or acute symptomatic epileptic seizures.