Am J Psychiatry 1997; 154:1076-1080
Copyright © 1997 by American Psychiatric Association
Startle reflex abnormalities in women with sexual assault-related posttraumatic stress disorder
CA Morgan 3rd, C Grillon, H Lubin and SM Southwick
Department of Psychiatry, Yale University School of Medicine, New Haven, Conn, USA.
OBJECTIVE: This investigation was designed to assess the acoustic startle
response in treatment-seeking women with sexual assault-related
posttraumatic stress disorder (PTSD). METHOD: Thirteen patients with sexual
assault-related PTSD and 16 healthy female comparison subjects were
recruited for participation in the study. Each patient met the full
criteria for PTSD according to the Structured Clinical Interview for
DSM-III-R. All subjects in the study were right-handed. The acoustic
stimuli were bursts of white noise (92 dB and 102 dB) with a nearly
instantaneous onset delivered binaurally through headphones. RESULTS: The
magnitude of the startle response (eye blink) to the first stimulus was
asymmetrically distributed in the PTSD patients but not in the comparison
subjects: it was greater for the left eye than the right eye in the PTSD
patients only. There was a differential asymmetry of startle response in
the two subgroups of patients (recent PTSD and long- standing PTSD): the
startle reflex was larger for the left eye than the right in the subgroup
with recent PTSD but not in the group with long- standing PTSD.
CONCLUSIONS: This study provides the first objective evidence of startle
abnormalities in women with PTSD. The significantly greater startle
responses for the left eye compared with the right in the PTSD subjects
suggest a laterality effect. As suggested by the preclinical model of shock
sensitization, it is possible that in a subgroup of individuals with PTSD,
trauma may sensitize the startle reflex. This model may hold true in humans
and is supported by the findings of greater startle response in the
patients with recent-onset PTSD.
