Acute stress reactions in adults

This article summarizes the literature on acute reactions to traumatic stress in adults. It describes their morphology, natural course, long-term outcome, and underlying biological factors, and outlines directions for management and research. It assumes two categories of responses: those that mediate survival and those related to learning and adaptation. The complementary roles of fear conditioning, processing novelty, and adjusting to change are discussed. (C) 2002 Society of Biological Psychiatry.