Does thyroid supplementation accelerate tricyclic antidepressant response?A review and meta-analysis of the literature

objective: The delayed onset of therapeutic response to antidepressants rem ains a major problem in the treatment of depression. Among the strategies t o accelerate response to treatment, the early addition of thyroid hormone t o antidepressants has been suggested as a viable method. The authors perfor med a metaanalysis of the literature on the use of thyroid hormone suppleme ntation to accelerate the treatment of depression to determine whether ther e is sufficient evidence to support the clinical efficacy of this strategy. Method: Both a computer-aided search of the National Library of Medicine ME DLINE and an intensive search by hand were conducted to identify all double -blind, placebo-controlled studies assessing the concomitant administration of thyroid hormone and antidepressant to accelerate clinical response in p atients with nonrefractory depression. Results: Six studies were identified. All were conducted with triiodothyron ine (T-3) and a tricyclic antidepressant. Five of the six studies found T-3 to be significantly more effective than placebo in accelerating clinical r esponse. The pooled, weighted effect size index was 0.58, and the average e ffect was highly significant. Further, the effects of T-3 acceleration were greater as the percentage of women participating in the study increased. Conclusions: This meta-analysis supports the efficacy of T-3 in acceleratin g clinical response to tricyclic antidepressants in patients with nonrefrac tory depression. Furthermore, women may be more likely than men to benefit from this intervention.