Lamotrigine and antiepileptic drugs as mood stabilizers in bipolar disorder

Objective: To review the clinical trials literature on the use of antiepileptic drugs (AED) as mood stabilizers and to suggest an evidence-based approach when utilizing these agents in bipolar disorder. Method: The literature is reviewed and subdivided into the following sections: carbamazepine and oxcarbazepine, valproate, lamotrigine, gabapentin and other AED, and discussion. Results: Data exist to support the use of carbamazepine and valproate - and to a lesser extent, oxcarbazepine - in the management of acute manic episodes associated with bipolar I disorder. Lamotrigine, gabapentin, and other AED have not demonstrated consistent anti-manic effects. Clinical trials data favor lamotrigine over all other AED in the treatment of acute bipolar I depression and in rapid cycling bipolar disorder (particularly type II), although the absence of an active comparator in these lamotrigine trials must be noted. Lamotrigine, carbamazepine, and valproate all have evidence supporting their roles as potential long-term mood stabilizers to prevent bipolar relapse, with lamotrigine having a stronger effect in the prevention of depression. Conclusion: The AED are a heterogeneous group of medications with differential spectrum of efficacy in the treatment of bipolar disorder.