Protirelin (formally known as thyrotrophin releasing hormone [TRH]) was evaluated as a treatment in depression in two independent investigations using a similar protocol. The latter was designed so that some patients received three 600μg intravenous injections of protirelin early in their course and others received them toward the end of their course of treatment. Regardless of when protirelin was given in the course of depression, or how the course of the illness was measured, it seemed to be devoid both of therapeutic and of major adverse effects.
Hollister LE, Berger P, Ogle FL, Arnold RC, Johnson A. Protirelin (TRH) in Depression. Arch Gen Psychiatry. 1974;31(4):468-470. doi:10.1001/archpsyc.1974.01760160024006