Background: The objective of this study was to determine the clinical and quality of life outcomes associated with adjunctive treatment of olanzapine added to either lithium or valproic acid/divalproex sodium in patients with bipolar disorder.
Methods: Patients with bipolar I disorder, were randomized to receive either olanzapine (5-20 mg) added to mood stabilizer therapy (n=224), or placebo added to mood stabilizer therapy (n=112) for 6 weeks. Changes in clinical outcomes over 6 weeks were measured by the Young Mania Rating Scale (Y-MRS) and the Hamilton Rating Scale for Depression (HAM-D). Quality of life was measured by the Lehman Brief Quality of Life Interview (QLI).
Results: Patients treated with olanzapine added to mood stabilizers, experienced significantly greater mean clinical improvements from baseline on both the Y-MRS and the HAM-D compared to those treated with placebo added to mood stabilizers. Over 6 weeks, patients treated with olanzapine added to mood stabilizers had significantly greater mean improvements from baseline on five of the nine subjective scales on the QLI, compared to patients treated with placebo added to mood stabilizers. Changes in scores on the subjective scales of the QLI were more strongly correlated to changes in depressive symptomatology measured by the HAM-D, than to changes in symptoms of mania measured by the Y-MRS.
Conclusion: The results of this study demonstrate that patients receiving adjunctive treatment have significantly greater improvements in both clinical and quality of life outcomes compared to monotherapy with mood stabilizers.