Abstract
The majority of adults in the United States will experience a potentially traumatic event during their lifetime, yet only a subset will develop posttraumatic stress disorder (PTSD). The trajectory of symptoms in the period of time immediately following the trauma (the acute post-trauma period) may be important in determining which individuals develop PTSD. The current study examined trajectories of PTSD symptom severity across the acute post-trauma period and if membership in these trajectories was predictive of PTSD symptom severity, depression symptoms, and functional impairment 1- and 3-months post-trauma. Four trajectories were identified: low and decreasing, rapid decreasing, slow decreasing, and consistently high. Further, trajectory membership in the acute post-trauma period was found to predict differences in PTSD symptoms, depression symptoms, and functional impairment severity at both 1- and 3- months post-trauma. These findings highlight a relationship between PTSD symptoms during the acute post-trauma period and later impairment.