Brain imaging in anxiety disorders.

Animal studies of the effects of stress on the brain have been used as a model for anxiety disorders. There is increasing evidence that brain areas involved in the stress response, including prefrontal cortex, hippocampus and amygdala, play a role in the symptoms of anxiety. In the past few years, brain imaging studies have been critical to advancing the understanding of the neural circuitry of anxiety disorders. Although some anxiety disorders may fit in with animal models of stress, both conceptually and in terms of imaging findings (e.g., post-traumatic stress and panic disorder), other anxiety disorders (e.g., obsessive-compulsive disorder) may require a more specific model to understand the neurobiology completely. This article reviews animal models for anxiety disorders, current brain imaging findings and outlines future directions for research in this area.