Auditory startle response in firefighters before and after trauma exposure.
OBJECTIVE
Although previous psychophysiological studies have revealed heightened muscular and autonomic responses in individuals with posttraumatic stress disorder (PTSD), these studies have not permitted inferences about whether the abnormal responses are a vulnerability factor or are acquired following trauma. The present study reports the first prospective psychophysiological investigation, to the authors' knowledge, of posttraumatic stress responses by prospectively evaluating the auditory startle response in firefighters before and after trauma exposure.


METHODS
Orbicularis oculi (eye blink) electromyograms and skin conductance responses to 15 100-dB acoustic startle stimuli were assessed in 84 trainee firefighters before trauma exposure. After commencement of active duty, 35 firefighters were reassessed within 4 weeks of exposure to a traumatic event, and 36 firefighters were reassessed as a comparison group that was not exposed to trauma.


RESULTS
In the trauma-exposed group, pretrauma physiological activity was predictive of posttrauma acoustic startle responses. Pretrauma skin conductance response to startle was also predictive of posttraumatic stress severity.


CONCLUSIONS
These results provide initial support for elevated startle response being a vulnerability factor for posttraumatic stress responses.
Guthrie
Rachel M
RM
School of Psychology, University of New South Wales, Sydney, NSW 2052, Australia.
Bryant
Richard A
RA
D000161:Acoustic Stimulation; D000328:Adult; D001307:Auditory Perception / Q000502:physiology; D001767:Blinking / Q000502:physiology; D004198:Disease Susceptibility / Q000175:diagnosis / Q000503:physiopathology; D004576:Electromyography; D005390:Fires; D005712:Galvanic Skin Response / Q000502:physiology; D006801:Humans; D008297:Male; D009784:Occupational Diseases / Q000175:diagnosis* / Q000503:physiopathology; D016273:Occupational Exposure; D010555:Personality Inventory; D011336:Probability; D011446:Prospective Studies; D011569:Psychiatric Status Rating Scales; D013216:Reflex, Startle / Q000502:physiology*; D012720:Severity of Illness Index; D013313:Stress Disorders, Post-Traumatic / Q000175:diagnosis* / Q000503:physiopathology