Depression in secondary epilepsy: relation to lesion laterality.

Patients with epilepsy often have depressive disorders. This association may be particularly prominent in secondary epilepsy from a left hemisphere lesion. Among 1611 outpatients with epilepsy 272 patients were identified whose seizures originated from a structural brain lesion other than mesial temporal sclerosis. Sustained depressive disorders had occurred in 25 (9%) of these patients with secondary epilepsy. The depressed patients were compared with the remaining patients without depression with regard to location of lesion laterality and seizure variables. The only group difference was unilateral left hemisphere lesions in 58% of the patients with depression compared with only 21% of the non-depressed patients (chi 2 = 10.4, p = 0.006). This finding supports the idea of a relation of depression with epileptogenic lesions in the left hemisphere.