The neurobiology of anxiety disorders.

The use of pharmacologic challenges and the application of new brain imaging technologies in the study of patients with anxiety disorders have led to an improvement in the understanding of the neurobiologic basis of these disorders. Abnormal function of noradrenergic, serotonergic, GABAergic, and dopaminergic neural systems as well as abnormal chemoreceptor reactivity have all been implicated in the pathophysiology of anxiety. Functional imaging data have revealed abnormal patterns of cortical and subcortical activity in anxiety patients. These data have allowed significant improvements in the available anatomic models of the anxiety disorders. Further improvements in research technique and technology likely will lead in the near future to a significantly clearer image of the neurobiologic processes involved in anxiety disorders.