LAUSR

When our group first began to discover examples and mechanisms mediating the immuno-enhancing effects of stress (Dhabhar, Miller, McEwen, & Spencer, 1995; Dhabhar & McEwen, 1996; en, 1997), we realized that it was important to define stress in terms of its key components, and to define and distinguish the types of stress responses that induce positive/protective effects versus those that induce negative/harmful effects. Numerous definitions have been proposed for the concept of stress, focusing on aspects of an internal or external challenge/stimulus; on stimulus perception; or on a physiological response to the stimulus (Goldstein & McEwen, 2002; McEwen, 2002; Sapolsky, 2005). While each definition focuses on an important component of stress, confusion often arises when investigators from different disciplines inadvertently use the term “stress” while referring to the stressor, or to stress perception, or to the stress response. Therefore, we proposed an integrated definition, highlighting the role of all three components of stress, stating that stress is a constellation of events, consisting of a stimulus (stressor), that precipitates a reaction in the brain (stress perception), that activates physiological fight or flight systems in the body (stress response) (Dhabhar, 2014; Dhabhar, 2018; Dhabhar & McEwen, 1997).