N-acetylcysteine for major depressive episodes in bipolar disorder.

Objective: In this report, we aimed to evaluate the effect of add-on N-acetylcysteine (NAC) on depressive symptoms and functional outcomes in bipolar disorder. To that end, we conducted a secondary analysis of all patients meeting full criteria for a depressive episode in a placebo controlled trial of adjunctive NAC for bipolar disorder.

Method: Twenty-four week randomised clinical trial comparing adjunctive NAC and placebo in individuals with bipolar disorder experiencing major depressive episodes. Symptomatic and functional outcome data were collected over the study period.

Results: Seventeen participants were available for this report. Very large effect sizes in favor of NAC were found for depressive symptoms and functional outcomes at endpoint. Eight of the ten participants on NAC had a treatment response at endpoint; the same was true for only one of the seven participants allocated to placebo.

Discussion: These results indicate that adjunctive NAC may be useful for major depressive episodes in bipolar disorder. Further studies designed to confirm this hypothesis are necessary.