To the Editor: Recently, we found that greater norepinephrine transporter (NET) availability in the locus ceruleus of trauma survivors with posttraumatic stress disorder (PTSD) was associated with increased severity of anxious arousal (ie, hypervigilance and exaggerated startle) symptoms, but not any of the other empirically derived symptom clusters that characterize this disorder.1 This finding suggests that greater NET availability in the locus ceruleus may serve a compensatory function of clearing elevated synaptic norepinephrine and maintaining anxious arousal symptoms in persons with PTSD
