Newer Anticonvulsants in the Treatment of Bipolar Disorder

The anticonvulsants valproate and carbamazepine have efficacy in treating acute mania, but theirefficacy in treating acute bipolar depression and preventing mood episodes remains uncertain. Despitethis, and given their utility and widespread use, both are widely accepted as standard treatments forbipolar disorder. All the newer anticonvulsants that have become available during the last decade havebeen or are being assessed to determine their efficacy in the treatment of various phases of bipolardisorder. Among the newer anticonvulsants, some appear to have efficacy in treating core bipolarsymptoms, while others have efficacy in treating psychiatric comorbidity such as substance abuse oran anxiety disorder. Lamotrigine is the most widely studied and is effective in treating and preventingbipolar depression, and it is the only anticonvulsant approved by the U.S. Food and Drug Administrationas a maintenance treatment for bipolar disorder. Other newer anticonvulsants, levetiracetam, oxcarbazepine,phenytoin, and zonisamide offer promise, but further studies are required before they canbe recommended for routine use to treat bipolar disorder. Gabapentin and topiramate do not appear tohave efficacy in treating acute mania, but their utility in bipolar depression and prevention of moodepisodes has not been studied in double-blind trials. Pregabalin has utility in treating generalized anxietydisorder, but it has not been studied in bipolar disorder. Given the success of lamotrigine in treatingbipolar disorder, further double-blind controlled trials of the newer anticonvulsants in treating bipolardisorder are warranted. This article summarizes current evidence from trials of anticonvulsantsin bipolar disorder and makes recommendations for their clinical use.