Quetiapine for bipolar depression: a systematic review and meta-analysis.

Quetiapine has been proposed for depression in bipolar patients but a quantitative analysis is lacking. In the present paper, we review and meta-analyze available data about the short-term and long-term efficacy and tolerability of quetiapine for the depressive phase of bipolar disorder or bipolar depression. A literature research was carried out using three electronic databases. Studies providing measures of efficacy and tolerability of quetiapine, either as monotherapy or as augmentation, for bipolar depression were considered. Seven short-term studies and four maintenance studies were included. Short-term studies suggested that patients treated with quetiapine monotherapy were significantly more likely than patients treated with placebo and further active comparators to achieve higher response and remission rates as well as more clinical improvements at the endpoint. Such benefits were significant from the first weeks of treatment onward. Maintenance studies suggested that the combination of quetiapine and mood stabilizers was significantly better than placebo plus mood stabilizers for the prevention of both depressive and manic relapses. Quetiapine was generally well tolerated. Furthermore, several clinical variables moderated outcomes under investigation. In conclusion, quetiapine could have some advantages over traditional treatments for the treatment of bipolar depression.