general adaptation syndrome (GAS) [L, genus, kind; L, adaptare, to fit; Gk, syn, together, dromos, course] , the defense response of the body or the psyche to injury or prolonged stress, as described by Hans Selye (1907–1982). It consists of an initial stage of shock or alarm reaction, followed by a phase of increasing resistance or adaptation in which the various defense mechanisms of the body or mind are used, and culminates in a state of adjustment and healing or of exhaustion and disintegration. Also called adaptation syndrome. See also alarm reaction, crisis, posttraumatic stress disorder, stress.
