Thyrotropin-releasing hormone: differential antidepressant and endocrinological effects

In a double-blind study, three depressed subjects received thyrotropin-releasing hormone (TRH) on three successive days, and one subject similarly received placebo; all subjects were then given ECT. Two of the patients given TRH responded to ECT. One patient's reaction is of special significance because of her response to ECT, diminished thyroid-stimulating hormone response to TRH, increased growth hormone and prolactin response to stress, and antidepressant effect of TRH. These findings raise the possibility that previous conflicting reports about TRH's antidepressant effects stem from the combined study of endocrinologically distinct depressive subgroups and strongly suggest that there may be a specific subgroup that is responsive to TRH.