Auditory startle responses in help-seeking trauma survivors.

Studies of the acoustic startle reflex in post-traumatic stress disorder (PTSD) yielded controversial results, whilst PTSD patients consistently report exaggerated startle. Addressing methodological difficulties of previous studies, the authors investigated the eyeblink, skin conductance and heart rate responses to 15 consecutive 95-dB, 500-ms, 1000-Hz sudden tones in 58 consecutive referrals of unmedicated help-seeking trauma survivors (30 with PTSD and 28 without PTSD). PTSD patients had higher average eyeblink and skin conductance responses to the tones. Differences between reports of exaggerated startle in PTSD and negative experimental findings may be explained by specific experimental conditions, such as reduced environmental input, and by concurrent use of medication.