Abstract
Panic disorder (PD) is characterized by recurrent, unprovoked attacks of somatic and cognitive symptoms of anxiety. While the causes of PD are not entirely understood, a hyper-reactive fear circuit involving the amygdala has been implicated in many previous studies of PD. Using functional magnetic resonance imaging, brain activity was evaluated in response to fear faces in unmedicated PD patients, remitted PD patients, and controls. Results revealed that PD patients showed increased amygdala response to fear faces compared to the other groups. Additionally, greater activity was found in the prefrontal cortex as well as greater connectivity between the amygdala and the periaqueductal gray in panic patients compared to the other groups. These results support models of panic disorder that include increased reactivity of the amygdala to fearful stimuli, however since this was not found in remitted panic patients this does not appear to be a trait feature of panic disorder.