Predicting Posttraumatic Stress Symptoms Following Mild, Moderate, and Severe Traumatic Brain Injury: The Role of Posttraumatic Amnesia.

Abstract

To explore the relation between posttraumatic amnesia (PTA) and posttraumatic stress symptoms in traumatic brain injury. Single-site prospective cohort study. A total of 1114 individuals between the ages of 18 and 65 years with a traumatic brain injury seen on average 3 months following injury. Participants were divided into 4 groups according to their duration of PTA: less than 1 hour; 1 to 24 hours; 24 hours to 1 week; and more than 1 week. Glasgow Coma Scale, PTA, computed tomographic brain scan abnormalities, Impact of Event Scale, the 28-item General Health Questionnaire, and Rivermead Postconcussion Disorder Questionnaire. The duration of PTA less than 1 hour was associated with more avoidant (P < .01) and intrusive (P < .001) posttraumatic stress symptoms and more anxiety according to the General Health Questionnaire (P < .01) than other groups. Regression analysis identified PTA and 3 concussive symptoms (light sensitivity, noise intolerance, and difficulties concentrating) as independent predictors of intrusive posttraumatic stress symptoms. Our data, representative of the full range of traumatic brain injury severity, indicate that a brief duration of PTA is a significant risk factor for the development of posttraumatic stress disorder symptoms. The persistence of certain symptoms of postconcussion disorder adds to the risk by possibly acting as a trigger for reminders of the traumatic event.