A pilot study of amygdala volumes in pediatric generalized anxiety disorder

Background: The neurodevelopment of childhood anxiety disorders is not well understood. Basic research has implicated the amygdala and circuits relate d to these nuclei as being central to several aspects of fear and fear-rela ted behaviors in animals. Methods: Magnetic resonance imaging was used to measure amygdala volumes an d comparison brain regions in 12 child and adolescent subjects with general ized anxiety disorder and 24 comparison subjects. Groups were matched on ag e, sex, height, and handedness and were also similar on measures of weight, socioeconomic status, and full scale Ie, Results: Right and total amygdala volumes were significantly larger in gene ralized anxiety disorder subjects. Intracranial, cerebral, cerebral gray an d white matter, temporal lobe, hippocampal, and basal ganglia volumes and m easures of the midsagittal area of the corpus callosum did not differ betwe en groups. Conclusions: Although these data are preliminary and from a small sample, t he results are consistent with a line of thinking that alterations in the s tructure and function of the amygdala may be associated with pediatric gene ralized anxiety disorder. (C) 2000 Society of Biological Psychiatry.