TRH in depressive illness

Among the four hypothalamic-releasing hormones (TRH, SRIF, LHRH, and MIF) with central nervous system actions and possibly with psychotropic properties, TRH is the one most systematically studied. Animal pharmacological data has confirmed the activity of TRH as a centrally acting agent with a widespread neurophysiological role independent of the pituitary-thyroid axis; and human pharmacological studies revealed that the computer EEG profile of TRH resembles psychostimulant drugs and secondary amine tricyclic antidepressants. Corresponding with this are the clinical findings that TRH produces a rapid but transient improvement in unipolar depression in women, a sense of increased energy and well-being, or increase of interest, desire and drive for work, food, and sex. In spite of the equivocal findings in some of the clinical studies, a recent investigation raised the possibility that a transient favorable response to TRH may identify a patient population responsive to maprotilline, or other norepinephrine uptake inhibitors.