A Multisite Analysis of the Fluctuating Course of Posttraumatic Stress Disorder

These data highlight the complex trajectories of PTSD symptoms over time. This study also points to the roles of ongoing stress and MTBI in delayed cases of PTSD and suggests the potential of ongoing stress to compound initial stress reactions and lead to a delayed increase in PTSD symptom severity. This study also provides initial evidence that MTBI increases the risk of delayed PTSD symptoms, particularly in those with no acute symptoms.