Efficacy of Olanzapine Monotherapy for Treatment Bipolar Ⅰ Depression

Olanzapine may have some antidepressant properties and olanzapine monotherapy has been shown efficacy in bipolar depressive episodes in retrospective studies. However, there has been no prospective study about the monotherapy of olanzapine. The investigators conducted a randomized, placebo-controlled study to test the efficacy of olanzapine monotherapy for treatment of the depressed phase of bipolar disorder.