Zonisamide for bipolar depression.

In recent years, research into bipolar depression has increased. Each year, more studies are published using different agents to treat this condition. In addition to effectiveness and tolerability, bipolar depression research has sought agents that do not induce cycling or mania. This paper evaluates an open-label pilot study on zonisamide for bipolar depression that examined the effectiveness and tolerability of this agent while observing for any switch to mania. Zonisamide was found to have a very low switch rate and modest effectiveness. However, a high dropout rate was observed--mostly due to side effects. Until further research is available, zonisamide is not recommended as a first-line treatment for bipolar depression.