Effects of Threat Context, Trauma History, and Posttraumatic Stress Disorder Status on Physiological Startle Reactivity in Gulf War Veterans

J Trauma Stress. 2018 Aug;31(4):579-590. doi: 10.1002/jts.22302. Epub 2018 Jul 30.


In the current study, we explored exaggerated physiological startle responses in posttraumatic stress disorder (PTSD) and examined startle reactivity as a biomarker of PTSD in a large veteran sample. We assessed heart rate (HR), skin conductance (SC), and electromyographic (EMG) startle responses to acoustic stimuli under low-, ambiguous-, and high-threat conditions in Gulf War veterans with current (n = 48), past (n = 42), and no history of PTSD (control group; n = 152). We evaluated PTSD status using the Clinician-Administered PTSD Scale and trauma exposure using the Trauma History Questionnaire. Participants with current PTSD had higher HR, ds = 0.28-0.53; SC, d = 0.37; and startle responses than those with past or no history of PTSD. The HR startle response under ambiguous threat best differentiated current PTSD; however, sensitivity and specificity analyses revealed it to be an imprecise indicator of PTSD status, ROC AUC = .66. Participants with high levels of trauma exposure only showed elevated HR and SC startle reactivity if they had current PTSD. Results indicate that startle is particularly elevated in PTSD when safety signals are available but a possibility of danger remains and when trauma exposure is high. However, startle reactivity alone is unlikely to be a sufficient biomarker of PTSD.

Publication types

  • Research Support, U.S. Gov't, Non-P.H.S.

MeSH terms

  • Adult
  • Case-Control Studies
  • Cross-Sectional Studies
  • Electromyography
  • Female
  • Galvanic Skin Response / physiology
  • Gulf War
  • Heart Rate / physiology
  • Humans
  • Male
  • Middle Aged
  • Reflex, Startle / physiology*
  • Severity of Illness Index
  • Stress Disorders, Post-Traumatic / diagnosis
  • Stress Disorders, Post-Traumatic / physiopathology*
  • Surveys and Questionnaires
  • United States / epidemiology
  • Veterans / psychology*