A prospective study of psychophysiological arousal, acute stress disorder, and posttraumatic stress disorder.

This study investigated the role of acute arousal in the development of posttraumatic stress disorder (PTSD). Hospitalized motor-vehicle-accident survivors (n = 146) were assessed for acute stress disorder (ASD) within 1 month of the trauma and were reassessed (n = 113) for PTSD 6 months posttrauma. Heart rate (HR) and blood pressure (BP) were assessed on the day of hospital discharge. Participants with subclinical ASD had higher HR than those with ASD and no ASD. Participants who developed PTSD had higher HR in the acute posttrauma phase than those without PTSD. Diagnosis of ASD and resting HR accounted for 36% of the variance of the number of PTSD symptoms. A formula composed of a diagnosis of ASD or a resting HR of > 90 beats per minute possessed strong sensitivity (88%) and specificity (85%) in predicting PTSD. These findings are discussed in terms of acute arousal and longer term adaptation to trauma.