Antidepressant properties of anticonvulsant drugs for bipolar disorder

A growing number of anticonvulsant drugs are receiving attention as possible mood stabilizers. This attention is based mainly on the assumption that the antimanic efficacy of anticonvulsants makes them suitable as mood stabilizers. However, their antidepressant properties have received less scrutiny. In this review, current evidence concerning the acute and prophylactic efficacy of divalproex, carbamazepine, gabapentin, lamotrigine, and topiramate in bipolar depression is evaluated. Clinical outcome data are considered, together with limitations of existing studies and the concept of unmet clinical needs. Findings in placebo-controlled trials suggest an acute and prophylactic antidepressant effect with lamotrigine monotherapy and more modest antidepressant benefits with other agents administered as monotherapies. Results of published studies are considered with respect to the conceptualization of mood stabilization as arising from antimanic and antidepressant efficacy in bipolar disorder.