Background: Clinicians may not consider using the thyroid hormone liothyronine sodium (levorotary isomer of triiodothyronine [T3]) for augmentation of antidepressant drugs in depressed patients who are also receiving the precursor hormone levothyroxine (levorotary isomer of thyroxine [T4]) for thyroid disease. We now report on the successful use of T3 augmentation therapy in seven of nine depressed patients who were also receiving T4 for thyroid disease.
Method: Following an earlier single case report, we prescribed T3 augmentation therapy for eight depressed patients who had not responded to an adequate antidepressant drug trial and who were receiving T4 therapy for thyroid disease. T3 was prescribed in open-label fashion, and response was judged by the clinician, whose assessment was supplemented by the use of standardized rating scales.
Results: Seven of the nine patients were judged to respond to T3 augmentation.
Conclusion: These results are consistent with a report of differential effects for T3 versus T4 augmentation in depressed patients free of thyroid disease. The results have implications for the treatment of depression in the presence of thyroid disease and for the mechanism of thyroid hormone potentiation of antidepressants.