Thyroid Research Thyroid Research Archive Hypothyroidism

Thyroxine plus triiodothyronine and thyroxine alone have similar efficacy in hypothyroid patients who have depressive symptoms

(March 2004)

The background of the study. Patients with hypothyroidism who are treated with thyroxine (T4) may continue to have symptoms, particularly psychological symptoms. Treatment with T4 plus triiodothyronine (T3) may be helpful. In this study the effects of T4 alone and T4 plus T3 were compared in patients with hypothyroidism who had symptoms of depression.

How the study was done. Forty patients (36 women; mean age, 47 years) with hypothyroidism who had been taking a constant dose of T4 for at least six months and had symptoms of depression were studied. They were randomly assigned to receive their usual dose of T4 once daily plus a placebo twice daily, or half their usual dose of T4 once daily plus T3, 12.5 µg twice daily, for 15 weeks. The patients were evaluated using the Symptom Check-List-90 (SCL-90), the Comprehensive Epidemiological Screens for Depression (CES-D), and a general health questionnaire before and periodically during the study.

The results of the study. At the end of the study, the mean daily T4 dose was 118µg in the T4 group and 67µg in the T4-plus-T3 group, and the mean T3 dose in the latter group was 19µg. During and at the end of the study the mean serum thyrotropin concentrations in the two groups were similar. At base line, the scores for the subtests (depression, anxiety, global severity index, positive symptom total, and positive symptom distress index) of the SCL-90 test, the score for the CES-D test, and the results of the general health questionnaire were similar in both groups. The scores for the tests improved during the study, but there were no differences between the groups at any time.

The conclusions of the study. In patients with hypothyroidism and depressive symptoms despite adequate T4 therapy, the combination of T4 plus T3 is no more effective than T4 alone in ameliorating these symptoms.

The original article. Sawka AM, Gerstein HC, Marriott MJ, MacQueen GM, Joffe RT. Does a combination regimen of thyroxine (T4) and 3,5,3'-triiodothyronine improve depressive symptoms better than T4 alone in patients with hypothyroidism? Results of a double-blind, randomized, controlled trial. J Clin Endocrinol Metab 2003;88:4551-5.