Antidepressant monotherapy for bipolar type II major depression

Objectives: Bipolar type II (BP II) disorder is thought to be distinct from BP I disorder on genetic and biological grounds, and it is not merely a milder form of the illness. It affects 1.5-2.5% of the US adult population, and is characterized by highly recurrent depressive episodes with a substantial morbidity from alcoholism and non-affective psychopathology, and a higher suicide rate than either BP I or unipolar depression. Treatment recommendations for BP II depression are based upon concerns over drug-induced manic-switch episodes, and suggest using either a mood stabilizer alone or a combination of an SSRI plus a mood stabilizer. Recent evidence, however, indicates that the rate of manic switch episodes may be modest in BP II patients. Recent studies have provided evidence that antidepressant monotherapy may be an effective initial and long-term treatment for BP II major depression with a low manic-switch rate. Methods: In this article, we review the recent literature on BP II disorder, with a focus on the treatment of BP II major depression. Results: We present a summary of data from recent studies by our group and others indicating that antidepressant monotherapy for BP II depression may be safe and effective with a low manic-switch rate. Conclusion: Antidepressant monotherapy may be beneficial for some patients with BP II major depression.