Response to SSRIs, the most frequently used first-line agents for major depression, tends to be slow, and full remission is obtained by fewer than half of treated patients. Since thyroid function has recently been linked to symptoms of depression, researchers performed a double-blind, randomized, 8-week, placebo-controlled trial to find whether the thyroid hormone L-triiodothyronine (liothyronine [Cytomel]) would heighten the effects of treatment with the SSRI sertraline(Drug information on sertraline) (Zoloft). The results were published in the June issue of Archives of General Psychiatry.
A total of 124 adult patients who met DSM-IV criteria for major depressive disorder without psychotic features were recruited from outpatient referral centers. Patients were randomized to receive sertraline (50 mg/d for the first week, 100 mg/d thereafter) plus liothyronine(Drug information on liothyronine) (20 to 25 µg/d for the first week, 40 to 50 µg/d thereafter), or sertraline plus placebo.
As scored by the HAM-D, intent-to-treat response rates were 70% in the sertraline-liothyronine group versus 50% in the sertraline-placebo group (P = .02) and the total remission rates were 58% in the sertraline-liothyronine group versus 38% in the sertraline-placebo group (P = .02). Triiodothyronine levels were lower in patients who were treated with sertraline-liothyronine and had remissions than they were in those who received the same treatment but did not have remissions (P < .002). Remission was associated with a significant decrease in serum thyrotropin values among patients treated with sertraline-liothyronine (P < .05). There were no significant adverse effects reported in patients who were treated with liothyronine.
The authors stressed that the effectiveness of antidepressants could be enhanced as shown in the study and that future controlled studies are needed to "address the question of generalizability to SSRIs other than sertraline."