title: Acute stress disorder as a predictor of posttraumatic stress symptoms.
abstract: OBJECTIVE
  Using the DSM-IV diagnostic criteria for acute stress disorder, the authors examined whether the acute psychological effects of being a bystander to violence involving mass shootings in an office building predicted later posttraumatic stress symptoms.
  
  
  METHODS
  The participants in this study were 36 employees working in an office building where a gunman shot 14 persons (eight fatally). The acute stress symptoms were assessed within 8 days of the event, and posttraumatic stress symptoms of 32 employees were assessed 7 to 10 months later.
  
  
  RESULTS
  According to the Stanford Acute Stress Reaction Questionnaire, 12 (33%) of the employees met criteria for the diagnosis of acute stress disorder. Acute stress symptoms were found to be an excellent predictor of the subjects' posttraumatic stress symptoms 7-10 months after the traumatic event.
  
  
  CONCLUSIONS
  These results suggest not only that being a bystander to violence is highly stressful in the short run, but that acute stress reactions to such an event further predict later posttraumatic stress symptoms.
authors.affiliation: Department of Psychiatry and Behavioral Sciences, Stanford University School of Medicine, CA 94305-5718, USA. classen@leland.stanford.edu
authors.forename: C
authors.initials: C
authors.lastname: Classen
authors.forename: C
authors.initials: C
authors.lastname: Koopman
authors.forename: R
authors.initials: R
authors.lastname: Hales
authors.forename: D
authors.initials: D
authors.lastname: Spiegel
mesh_terms: D000208:Acute Disease; D000328:Adult; D000368:Aged; D015897:Comorbidity; D005260:Female; D005500:Follow-Up Studies; D006708:Homicide / Q000523:psychology; D006801:Humans; D008016:Life Change Events; D008297:Male; D008875:Middle Aged; D010555:Personality Inventory / Q000706:statistics & numerical data; D011336:Probability; D012307:Risk Factors; D013313:Stress Disorders, Post-Traumatic / Q000175:diagnosis* / Q000453:epidemiology / Q000523:psychology; D013315:Stress, Psychological / Q000175:diagnosis* / Q000453:epidemiology / Q000523:psychology; D009626:Terminology as Topic; D014754:Violence / Q000523:psychology