Treatment of bipolar depression

We did not cover bipolar II disorder specifically in our article,1 as there is little quality evidence to suggest that the depressive phases of bipolar II and bipolar I disorder should be treated substantially differently.2 Most data derive from examinations of subgroups of people with bipolar II disorder in broader bipolar cohorts. Differences may exist, including possibly lower rates of switching from depression to mania or hypomania, and greater potential utility of antidepressants in those with bipolar II disorder. However, these data are methodologically limited and thus controversial.3

The 2013 update of the Canadian Network for Mood and Anxiety Treatments (CANMAT) guidelines4 suggests first-line options for managing bipolar II depression include lithium, lamotrigine, valproate, lithium plus valproate, lithium or valproate plus antidepressants, and the combination of atypical antipsychotics and antidepressants. Second-line options include antidepressant monotherapy for those with infrequent hypomania, quetiapine plus lamotrigine, adjunctive electroconvulsive therapy, adjunctive N-acetylcysteine or adjunctive triiodothyronine. With the exception of greater latitude for antidepressant therapy, these recommendations differ minimally from those for bipolar I disorder.

Quality studies examining the treatment of this important subgroup are underway, and their results are eagerly awaited.