Effects on the Brain
Generalized Anxiety Disorder primarily affects the amygdala more than any other part of the brain. A study at Stanford University pinpointed key disruptions in the communications between the basolateral amygdala, located at the bottom of the amygdala, and the centromedial amygdala, located at the top of the amygdala.
In patients with GAD, the signals from the basolateral amygdala to all of its targets were dulled except to the centromedial amygdala, and vice versa. The study says that "this could mean that people with the disorder [GAD] have a harder time discerning truly worrisome situations from mild annoyances" (Etkin).