Neuropsychiatric complications of epilepsy.

Psychiatric complications of epilepsy are multiple and result from the complex interaction between endogenous, genetic, therapeutic, and environmental factors. The relationship between epilepsy and psychiatric disorders may be much closer than previously appreciated. Recent studies have suggested the existence of a bi-directional relationship between depression and epilepsy, whereby patients with epilepsy have a higher risk than the general population of suffering from depression, not only after, but also before the onset of epilepsy. Furthermore, similar neurotransmitter changes have been identified in depression and epilepsy, suggesting the possibility that these two disorders share common pathogenic mechanisms. Although the clinical manifestations of psychiatric disorders in epilepsy are often indistinguishable from those of nonepileptic patients, certain types of depression and psychotic disorders may present with clinical characteristics that are particular to epilepsy patients. These include the psychosis of epilepsy, postictal psychotic disorders, alternative psychosis (or forced normalization), and certain forms of interictal depressive disorders.