Brief Communication Lithium and Triiodothyronine Augmentation of Antidepressants

There are now sufficient data to suggest that lithium is an effective augmentation strategy for patients with major depression who have an inadequate response to all classes of antidepressants (1). A recent metaanalysis supports the efficacy of T3 in treatment-resistant depression (2); these studies involving T3 were in patients taking tricyclic antidepressants, although a recent study supports the efficacy of T3 in SSRI-resistant depression (3). Further, there is some clinical evidence that lithium and T3, which both work as an augmentation strategy in up to 50% of cases (1,2), may be effective in different subgroups of depression patients (4,5). We reasoned that combined lithium and T3 might produce greater improvement in depression scores than either alone and, therefore, carried out a direct comparison of lithium and T3 alone and a combination, using a 2-week, double-blind, placebocontrolled design.