Efficacy and safety of antidepressant monotherapy in the treatment of bipolar-II depression

Sparse data exist regarding the risks and benefits of treating bipolar-II depression with antidepressants alone. On the basis of studies of bipolar-I patients, treatment guidelines suggest antidepressants should be augmented with mood stabilizers. Whether these recommendations apply to bipolar-II is unclear. A post-hoc analysis of a double-blind study, which compared the relative efficacy of placebo, imipramine and phenelzine in depressed outpatients. Patients rated 1 ('very much improved') or 2 ('much improved') on the Clinical Global Inventory Scale were considered responders. In an intent to treat analysis, no significant differences between bipolar patients (N=62) and unipolar patients (N=248) in response rates to placebo, imipramine and phenelzine were seen. No patient developed manic symptoms that required medication discontinuation or mood stabilizer augmentation. Antidepressant monotherapy was found to be a safe and effective treatment for bipolar-II depression.