Diagnosis and management of patients with bipolar II disorder.

Bipolar II disorder is frequently misdiagnosed as major depressive disorder. In particular, correct diagnosis of bipolar II disorder may be delayed by years due to the predominance of depressive symptoms and the relative subtlety of hypomania, which may manifest only briefly and without elevated mood. The prevalence of bipolar II disorder varies from 0.5% to about 5% depending on the criteria used. Diagnosis can be improved by using mood disorder questionnaires, systematic probing, and prospective mood diary charting. There is a dearth of research into treatment of bipolar disorder. The limited available evidence suggests that lithium and lamotrigine may have efficacy in preventing relapse of mood episodes. Acute bipolar II depression could be treated with a combination of a mood stabilizer plus an antidepressant or pramipexole and in rare cases with antidepressant monotherapy. Hypomania will likely respond to monotherapy with antimanic agents. Adjunctive psychosocial treatments may provide additional benefit in patients with bipolar II disorder.