Bipolar II disorder: Symptoms, course, and response to treatment

The authors provide an overview of the diagnosis, course, and treatment of bipolar II disorder, a distinct subtype that is often misdiagnosed as unipo lar depression or bipolar I disorder. They discuss research suggesting that underdiagnosis of bipolar II disorder reflects a failure to identify subth reshold expression of mania (hypomania), The course of bipolar II disorder is different from that of bipolar I disorder or unipolar depression, with d istinct differences in rates of recovery, clinical features, and number of episodes. The risk of suicide appears to be particularly elevated. High rat es of comorbid disorders have been reported, including substance abuse or d ependence, anxiety disorders, and personality disorders, Few definitive stu dies exist on which to base conclusions about the differential efficacy of various treatment strategies in bipolar II disorder and bipolar I disorder, Preliminary studies suggest that the newer anticonvulsants may be of benef it for patients with bipolar II disorder, while other data suggest that the re may be a greater role for antidepressant medications.