Depression in epilepsy: symptom or syndrome?

An occurrence of depression or depressive symptomatology has been reported in 30% of patients with epilepsy. Depression has been reported peri- and interictally. To make a differentiation may be difficult in patients with frequent seizures. However, complex partial seizures, particularly if are located on temporal lobe, appear to be etiologic factors, especially in men with left-sided epileptic foci. Depression is also more frequent in patients treated with polytherapy, particularly with phenobarbital and vigabatrin. The depression appears to be endogenous and has also been described in patients with temporal lobectomy. Underlying risk factors (genetic, metabolic, etc) and some psychosocial condition also play a part and may explain the increased rates of depression in patients with epilepsy. Treatment approaches include psychotherapy, rationalization of antiepileptic drug medication and antidepressant treatment. The use of antidepressant treatment, in these patients, still raises uncertainties because of the widespread persuasion that this drugs exacerbated seizures. This adverse event is relatively uncommon at therapeutic dosages, and its incidence with some of most frequently used antidepressant drugs is close to that of spontaneous seizures calculated for the general population, but the incidence may rise up to 30-40% after overdosage. On the basis of the data reported in literature, it appears fair to say that maprotiline and amoxapine show the greatest seizure risk, whereas trazodone, fluoxetine and fluvoxamine show the least. The data also showed that antidepressant drugs may display both convulsant and anticonvulsant effect and it is likely that the most important factor to assess the effect of a given antidepressant drug in terms of inhibition-excitation is drug dosage. Nevertheless, further studies are needed in this field, both to clarify the complex modulating effects of antidepressants on seizure threshold and to identify clearer and safer guidelines to manage the treatment of patients with epilepsy and concomitant depression.