Neural circuitry of anxiety: evidence from structural and functional neuroimaging studies.

Present understanding of the neural circuitry of anxiety has come from a variety of sources, including animal, clinical, and most recently, neuroimaging studies. Evidence from these sources has converged to form a translational bridge from animal models to human pathophysiology. In particular, the classical fear conditioning paradigm has served as a foundation for this bridge. Proposed models for the neural circuitry of normal anxiety as well as the anxiety disorders are discussed. A brief review of specific findings from neuroimaging studies of posttraumatic stress disorder, specific phobia, social phobia, obsessive-compulsive disorder, and generalized anxiety disorder is also provided.