[Neuroimaging and pathology in anxiety disorders, especially stress-induced fear circuitry disorders]

Anxiety disorders are a significant problem in the community. Brain imaging study, mainly study on MRI, f-MRI, MRS, PET, SPECT and NIRS, has recently advanced and has focused on determining the brain circuits that underlie them. In this article, we reviewed recent knowledge and a biological base of anxiety disorders, especially stress-induced fear circuitry disorders (SFCDs) such as panic disorder, social anxiety disorder, posttraumatic stress disorder, and specific phobias. In animal models and the study of brain responses to emotional stimuli in healthy subjects, research on the neuro-circuitry of the SFCDs has its roots in the study of fear circuits. Generally, these studies have reported relatively heightened pathological amygdala activation in response to disorder-related stimuli. The amygdala is a brain structure that is critically involved in the processing of memory and emotion, including fear and anxiety. In this review, we discuss the functional and neuro-anatomical hypotheses of pathology of the SFCDs in detail, including the neural circuit of hypothesis of Gorman et al. (2000).