Initial symptoms and reactions to trauma-related stimuli and the development of posttraumatic stress disorder

We investigated laboratory and experimental variables as predictors of the development of posttraumatic stress disorder (PTSD). Evoked heart rate response to trauma-related pictures, attentional bias in the dot-probe task, and viewing time were assessed in 35 victims of a traumatic event and again after 3 months. Data was compared to 26 control participants. At first assessment trauma victims showed heart rate (HR) acceleration and controls showed HR deceleration to trauma-related material. The group of trauma victims improved clinically over time. Predictors of the number of PTSD symptoms after 3 months were re-experiencing (33% of the variance) and amplitude of the evoked HR reaction to trauma-related pictures (15%). The two variables were highly correlated. Trauma victims were also more anxious, viewed trauma-related pictures for a longer time, and had a longer reaction time in the dot-probe task (but no distinct attentional bias) than control participants. Results indicate that specific fear responses and re-experiencing contribute to the development of posttraumatic stress disorder.