Prevalence and Course of Symptom-Defined PTSD in Individuals Directly or Indirectly Exposed to Terror: A Longitudinal Study.

Individuals indirectly exposed to terrorism may develop long-lasting posttraumatic stress reactions fulfilling PTSD symptom criteria. Due to the large number of individuals that may be indirectly exposed to terrorism, even a low risk of PTSD may result in high numbers of individuals with substantial posttraumatic stress. Our findings have implications for the planning and implementation of health care services beyond those directly exposed after large-scale terror events.