Auditory startle reflex in post-traumatic stress disorder patients treated with clonazepam.

Manifestations of acute hyperarousal in the Post-Traumatic Stress Disorder (PTSD) have been assimilated with panic attacks. This study examines the auditory startle reflex in PTSD patients treated with clonazepam, a benzodiazepine with anti-panic properties. PTSD patients treated with clonazepam did not differ from drug-free PTSD patients in the magnitude and the habituation rate of their responses to an auditory startle, with both groups showing abnormally slow habituation. It is suggested that the mechanisms underlying phasic hyperarousal in PTSD might differ from those which have been implied in the genesis of panic attacks.