Background: The neurodevelopment of childhood anxiety disorders is not well understood. Basic research has implicated the amygdala and circuits related to these nuclei as being central to several aspects of fear and fear-related behaviors in animals.
Methods: Magnetic resonance imaging was used to measure amygdala volumes and comparison brain regions in 12 child and adolescent subjects with generalized anxiety disorder and 24 comparison subjects. Groups were matched on age, sex, height, and handedness and were also similar on measures of weight, socioeconomic status, and full scale IQ.
Results: Right and total amygdala volumes were significantly larger in generalized anxiety disorder subjects. Intracranial, cerebral, cerebral gray and white matter, temporal lobe, hippocampal, and basal ganglia volumes and measures of the midsagittal area of the corpus callosum did not differ between groups.
Conclusions: Although these data are preliminary and from a small sample, the results are consistent with a line of thinking that alterations in the structure and function of the amygdala may be associated with pediatric generalized anxiety disorder.