It is now clear that the class of antiepileptic drugs (AED) constitute a heterogeneous grouping of medications with diverse medical applications. In particular, the spectrum of psychiatric uses of these medications has grown substantially. Valproate and carbamazepine are commonly used in the treatment of bipolar mania, lamotrigine in bipolar depression, and gabapentin in various anxiety disorders. Only divalproex sodium and carbamazepine have received regulatory approval in various countries around the world. This article will review the double-blind, placebo-controlled literature regarding the safety and spectrum of efficacy associated with the use of the above drugs in mood and anxiety disorders.