Combined Thyroid (Triiodothyronine)‐Tricyclic Antidepressant Treatment in Depressive States

It has been known as a result of experiments on animals that a part of the effect of imipramine, a tricyclic antidepressant, is enhanced in hyperthyroid mice compared with mice with normal thyroid function (Prange et al.? 1962). Prange et al. further observed in one case of hypothyroidism with a depressive state, that paroxysmal auricular tachycardia which was not found in single use of thyroid hormone occurred when they combined imipramine with thyroid hormone. Thus, the possibility that the hyperthyroid state or the administration of thyroid hormone enhances the effect of imipramine was suggested. Based upon these facts, Prange etal. (1 969) attempted to treat depressive patients with normal thyroid function, with a combination of the therapeutic dose of imipramine with a small dose of thyroid hormone (triiodothyronine, abbreviated as TS hereafter) and found that the effect appeared earlier than in the case of administration of imipramine alone. Since then, a number of evidences supporting this finding have been reported (Wilson et al.,13 1970; Earle,5 1970; Coppen et a1.,3 1972), but it has been reported also that there is no significant differ-