Publisher Summary This chapter reviews the hypothalamic releasing hormones and catecholamines. Ten women, ages 25-45, with primary, unipolar depression but in good physical health were treated in a double-blind, placebo-controlled, crossover design. Thyrotropin releasing hormone (TRH) acted alone rather than in combination with Imipramine, and that a single injection acted very rapidly though transiently. In this experiment as well as in the experiments with normal and schizophrenic women, psychological and behavioral changes were demonstrated in an environment characterized by pleasant stability and the absence of environmental noise such as may be introduced by intensive psychotherapeutic intervention. That behavioral effects occur in humans, at least with TRH seems certain. The effects have been shown to occur in normal and depressed women and are suggested by a single-blind study of schizophrenic women. The effects of a single injection are rapid, occurring within a few hours, and lasting not more than a few days. They are best demonstrated in a pleasant, stable, and relatively noise free environment. The effects are subtle, and it seems likely that intrinsic hormonal effects may be amplified or dampened by the environment.