Vulnerability: A new view of schizophrenia.

Although descriptive and etiological approaches to psychopathology have made notable advances, they seem to have reached a plateau. After reviewing the six approaches to etiology that now preempt the field—ecological, developmental, learning, genetic, internal environment, and neurophysiological models—a second-order model, vulnerability, is proposed as the common denominator, and methods for finding markers of vulnerability are suggested in the hope of revitalizing the field. It is assumed that exogenous and/or endogenous challengers elicit a crisis in all humans, but depending on the intensity of the elicited stress and the threshold for tolerating it, that is, one's vulnerability, the crisis will either be contained homeostatically or lead to an episode of disorder. Vulnerability and episode stand in a trait-state relation, and markers for each must be provided to distinguish between them.