Corticotropin-releasing hormone , originally named corticotropin-releasing factor , and also called corticoliberin, is a polypeptide hormone and neurotransmitter involved in the stress response. Corticotropin-releasing hormone is a 41-amino acid peptide derived from a 191-amino acid preprohormone. CRH is secreted by the paraventricular nucleus of the hypothalamus in response to stress. Marked reduction in CRH has been observed in association with Alzheimer disease, and autosomal recessive hypothalamic corticotropin deficiency has multiple...
It sounds more like the "it" may be cortisol or another corticosteroid which has negative feedback on the hypothalamus, thereby leading to a decrease in CRH's affect on ACTH secretion....