Anxiety disorders

Abstract

here is a bewildering diversity of tests that claim face, construct, and/or predictive validity as animal models of anxiety disorders (for a recent review see Cryan and Sweeney, 2011). Most of these procedures use rats or mice as subjects and involve exposure of subjects to external (e. g., cues earlier paired with footshock, bright light, predator) or internal (e. g., drug states) stimuli that are assumed to be capable of inducing anxiety in animals. The last two decades have seen the emergence of endophenotypemodels of anxiety, which are oten referred to as trait anxiety tests. Endophenotypes do not vary from moment to moment and are considered to be enduring features of an individual. They are cognitive, psychological, anatomical, or biochemical traits, which are hereditary and represent reliable markers of both the disease state and disease risk (Hasler et al., 2004). It has been suggested that the endophenotypes observed in anxiety disorders represent facets of disease more amenable to the development of animal models (Gottesman and Gould, 2003). Indeed, the traits encountered in anxiety disorders such as autonomic hyperarousal, trauma-induced cognitive deicits, compulsatory behaviors, startle response, sleep disturbances, and avoidance or diiculty to escape areas can all be readily modeled (Cryan and Holmes, 2005).