Startle responses in motor vehicle accident survivors: a pilot study

The aim of the present study was to investigate startle responses in motor vehicle accident (MVA) survivors to trauma-related, startle, and neutral sounds. Participants were 17 MVA survivors, 11 of whom participated in a controlled treatment study comparing cognitive-behavioral treatment (CBT) and supportive therapy (ST) versus a waitlist condition. Though participants differed significantly in their pretreatment clinical status and symptom severity, these differences were not reflected by group differences in EMG (at orbicularis oculi) to the stimuli at the initial assessment. Some cue-specificity was found, as all participants showed larger startle responses to trauma-related sounds, compared to startle and neutral sounds. At posttreatment, a significant reduction in EMG reactivity to all stimuli was observed in participants who received active treatment (either CBT or ST), compared to waitlist controls. The use of startle responses as a PTSD treatment outcome index is discussed.