Mental & Emotional HealthThis Is Your Brain on Anxiety By articleAccording to the National Institute of Mental Health, over 18 percent of American adults suffer from anxiety disorders. These people suffer from excessive worry or tension that often leads to physical symptoms. A release from the California Institute of Technology reports that previous studies of anxiety in the brain have focused on the amygdala, an area known to play a role in fear. However, Caltech researchers had a hunch that understanding a different brain area, the lateral septum, could provide more clues into how the brain processes anxiety. Their instincts paid off.