First maintenance therapy with proven efficacy in the prevention of depression following manic or depressive episodes in bipolar disorder.

Two 18-month, landmark, clinical trials, involving a total of 638 patients, investigated Lamictal as a maintenance treatment for patients with bipolar disorder. Lamictal was significantly more effective in preventing depressive episodes following either manic or depressive episodes compared with placebo. The prophylactic efficacy of Lamictal was not dependent on the polarity of the most recent mood episode.

Competitive counterclaims:

Olanzapine: OFC is effective in bipolar depression