Novel anticonvulsants: a new generation of mood stabilizers?

Accumulating evidence suggests that at least some novel anticonvulsants may have mood-stabilizing properties. This paper reviews the literature for empirical studies of this topic. Lamotrigine has the most evidence in favor of its efficacy, with two double-blind studies in which it was more efficacious than placebo in the treatment of bipolar depression. However, it is associated with a 1/1000 risk of potentially fatal Stevens-Johnson syndrome. Gabapentin, although safe and well-tolerated, has been found in two double-blind studies not to be efficacious in treatment-refractory mania or refractory bipolar depression. Topiramate is currently supported only by naturalistic evidence of mild to moderate mood-stabilizing efficacy, but it has the advantage of often producing weight loss. Based on these data, lamotrigine may be effective, in monotherapy or as an adjunct, for treating depression in type I bipolar disorder, but suggestions regarding gabapentin and topiramate await further efficacy data. Most of the current findings derive from small, non-double-blind studies, and further research is required before clinicians can consider any of these agents to be mood stabilizers.