The efficacy of valproate, lamotrigine and gabapentin in bipolar disorder; review of double-blind controlled studies

Aims: The efficacy of the anticonvulsants valproate, lamotrigine and gabapentin in bipolar disorder is reviewed. Method: Using Medline ® and other sources of information, 12 double-blind controlled studies with either of these compounds were identified. Results: None of the compounds has been proven effective in the prophylaxis of bipolar disorder. Valproate has been found an effective drug in acute mania, while in continuation treatment after acute mania it proved to be save, i.e. not causing switches into depression. Lamotrigine is the only anticonvulsant with proven efficacy in acute bipolar depression. So far gabapentin has not been found effective. Conclusion: For the prophylaxis of bipolar disorder, lithium is still the treatment of choice. Carbamazepine and valproate are good alternatives, especially for patients not responding to lithium or not tolerating it. Lamotrigine may be a good alternative in bipolar depression.