STARTLE REFLEX ABNORMALITIES IN WOMEN WITH SEXUAL ASSAULT-RELATED POSTTRAUMATIC-STRESS-DISORDER

Objective: This investigation was designed to assess the acoustic star tle response in treatment-seeking women with sexual assault-related po sttraumatic stress disorder (PTSD). Method: Thirteen patients with sex ual assault-related PTSD and 16 healthy female comparison subjects wer e recruited for participation in the study. Each patient met the full criteria for PTSD according to the Structured Clinical Interview for D SM-III-R. All subjects in the study were right-handed. The acoustic st imuli were bursts of white noise (92 dB and 102 dB) with a nearly inst antaneous onset delivered binaurally through headphones. Results: The magnitude of the startle response (eye blink) to the first stimulus wa s asymmetrically distributed in the PTSD patients but not in the compa rison 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-standi ng PTSD): the startle reflex was larger for the left eye than the righ t in the subgroup with recent PTSD but not in the group with long-stan ding PTSD. Conclusions: This study provides the first objective eviden ce of startle abnormalities in women with PTSD. The significantly grea ter startle responses for the left eye compared with the right in the PTSD subjects suggest a laterality effect. As suggested by the preclin ical model of shock sensitization, it is possible that in a subgroup o f individuals with PTSD, trauma may sensitize the startle reflex. This model may hold true in humans and is supported by the findings of gre ater startle response in the patients with recent-onset PTSD.