Am J Psychiatry 1996; 153:64-68
Copyright © 1996 by American Psychiatric Association
Exaggerated acoustic startle reflex in Gulf War veterans with posttraumatic stress disorder
CA Morgan 3rd, C Grillon, SM Southwick, M Davis and DS Charney
National Center for Post-Traumatic Stress Disorder, West Haven VA Medical Center, CT 06516, USA.
OBJECTIVE: Exaggerated startle reflex is reputed to be one of the cardinal
symptoms of posttraumatic stress disorder (PTSD). The goal of this study
was to assess the magnitude of the acoustic startle reflex in Gulf War
veterans with PTSD. METHOD: The eye-blink component of the startle reflex
was measured in response to six blocks of pseudorandomized 40-msec white
noise bursts of varying intensities (90, 96, 102, 108, and 114 dB) in 10
Gulf War veterans with PTSD, seven Gulf War veterans without PTSD, and 15
civilian subjects without PTSD. RESULTS: The magnitude of the first startle
response, as well as the magnitude of startle response averaged across
blocks of testing, was significantly greater in Gulf War veterans with PTSD
than in veteran and civilian comparison groups. CONCLUSIONS: Consistent
with some clinical studies investigating the startle response in Vietnam
veterans with PTSD, this investigation provides evidence for exaggerated
startle response in this disorder. Preclinical studies of shock
sensitization of the startle response suggest that the higher levels of
startle response seen in the PTSD subjects may reflect a sensitization of
the fear/alarm response created by the stress of combat trauma.
