Trauma processing and the development of posttraumatic stress disorder.

Most people are exposed to at least one violent or life-threatening situation during the course of their lives (Ozer, Best, Lipsey, & Weiss, 2003). As people progress through their life cycle, they are also increasingly confronted with the death of close friends or relatives. The prognosis varies by the type and intensity of trauma, with physical attack and witnessing someone hurt or killed at the highest risk for chronic symptoms (Breslau, 1998). However, there are great differences in how people deal with these highly aversive experiences. Although most trauma victims report PTSD symptoms immediately after experiencing a trauma, only one-third of the trauma victims show persistent symptoms and develop chronic PTSD (Kessler, Sonnega, Bromet, Hughes, & Nelson, 1995). One of the puzzles surrounding PTSD is which factors determine the maintenance of PTSD symptoms (see also Ehlers & Steil, 1995). Prospective studies have shown that early PTSD symptoms such as the frequency of initial intrusive recollections have little predictive power for chronic PTSD (Shalev, Freedman, Brandes, & Peri, 1997). Among the best candidates to explain the maintenance of PTSD symptoms are information-processing theories contending that the way the traumatic event is processed resulted in chronic