A heuristic vulnerability/stress model of schizophrenic episodes.

A tentative model of schizophrenic psychotic episodes is presented, based on the evidence that certain characteristics of individuals may serve as vulnerability factors and that environmental stressors may precipitate psychotic periods in vulnerable individuals. Certain information-processing deficits, autonomic reactivity anomalies, and social competence and coping limitations are viewed as potential vulnerability factors. Stressors in the form of discrete life events as well as the prevailing level of social environmental stress are seen as factors that interact with preexisting vulnerability characteristics to produce vicious circles, which lead, in turn, to psychotic episodes. A distinction among stable vulnerability indicators, mediating vulnerability factors, and episode indicators is suggested to differentiate types of abnormalities that characterize individuals prone to or manifesting schizophrenic disorder. Some major areas of unresolved questions in relation to this view of schizophrenic psychotic episodes are discussed.