A long-recognized association exists between epilepsy and affective disturbance, especially depression. People with complex partial seizures that result from temporal lobe seizure foci are highly vulnerable to psychiatric disorders. Accurate diagnosis of such disorders is an important key to treatment. Interictal depression or dysphoria is the most clinically significant problem of this type. Pharmacotherapeutic treatments that have positive effects in other types of depressive illness are also effective for depression associated with epilepsy. Electroconvulsive therapy is helpful to some patients with depression that is refractory to drug treatment or psychotherapy. Surgical resection of seizure foci may lead to psychiatric improvement for some individuals, but can also have psychiatric complications.