Specific Effects of Stress on Disease Processes

Abstract

The neuroendocrine system of a mammal is organized to respond in patterns of expectancy. Each species has evolved with the capacity to attain its own peculiar desiderata, e.g., appropriate diet, nest, and mate: challenges to these expectations arouse the sympathetic adrenal-medullary system. The ensuing behavior involves an irritable aggressivity designed to overcome the threat. The norepinephrine-to-epinephrine ratio increases with the physiological accompaniments of the raised catecholamine levels. Unfavorable early environmental experiences can create a mental set that views the current external milieu as a never-ending challenge. Such a stress-prone temperament is often associated with depressed gonadotropic activity and/or disturbed alimentary and cardiovascular function. The more anxious the organism becomes and doubts the fulfillment of expectancies, the more the pituitary-adrenocortical axis becomes implicated. Anxiety is accompanied by increasing levels of epinephrine. Acute events like bereavement, which abruptly deny expectancies, lead to a resetting of the limbic-pituitary-adrenocortical axis with helplessness and the depression that often accompanies it (2, 8, 10, 12).