Depression and schizophrenia in epilepsy: social and biological risk factors

Background: In a retrospective study we investigated the role of social and biological risk factors for the development of major depression and schizo phreniform psychoses in epilepsy. We tested the hypotheses that social risk factors are associated with depression and biological risk factors are ass ociated with schizophreniform psychoses. Method: We studied 25 patients wit h epilepsy and paranoid-hallucinatory psychosis, 25 patients with epilepsy and major depression, and 50 non-psychiatric epilepsy patients (controls) w ith respect to biological and psychosocial variables. Results: Schizophreni c patients had an earlier age of onset of epilepsy and a more severe epilep sy as characterised by history of status epilepticus, multiple seizure type s and severity of seizures compared to non-psychiatric controls. Simple sei zure symptoms were often vegetative and EEGs showed various abnormalities i ncluding temporal lobe discharges but no lateralisation to either side. Wit h respect to antiepileptic drugs (AED) there were only few significant diff erences between groups: Polytherapy as well as treatment with phenytoin (DP H) was more frequent in psychotic patients as compared to non-psychiatric p atients. Patients with psychoses were also characterized by a disturbed fam ilial background, lack of interpersonal relationships, social dependency an d professional failure. Depressive patients were significantly older than n on-psychiatric controls and they suffered more frequently from focal epilep sies arising from the temporal lobe. They did not differ from controls with respect to severity of epilepsy. Treatment with valproate (VPA) was invers ely linked with depression, suggesting that VPA may have prophylactic antid epressive properties in epilepsy patients. There were no psychosocial varia bles significantly linked with depression. Conclusions: In this study, pati ents with different forms of psychiatric complications in epilepsy could cl early be distinguished from controls. However, we could not confirm the sim ple hypothesis that there are biological predictors for schizophreniform ps ychoses and psychosocial predictors for major depression. Neurological and sociological variables seem linked with both, suggesting a multifactorial e tiology. (C) 1999 Elsevier Science B.V. All rights reserved.