Background: The addition of triiodothyronine (T(3)) is one of the most widely studied augmentation strategies for refractory depression. Despite this there are no long term studies or studies of doses above 100 mcg.
Method: Long term and high dose augmentation with T(3) for refractory unipolar major depression was studied. Seventeen patients were assessed for symptom improvement with the Clinical Global Impression of Improvement Scale.
Results: Fourteen of 17 patients showed improvement. One patient saw no improvement and 2 dropped out due to side effects. The patients who benefited showed an average CGI improvement of 2.5 (SD: 0.52). The average dose used was 80 mcg (SD: 30.2, range: 25 mcg-150 mcg). The average length of time on T(3) was 24.2 months (SD: 19.4, range: 11.8-86.7). This case series shows that T(3) may be successfully employed as a long term treatment augmentation of major depression if over time dosage levels are increased beyond the traditional 50 mcg.