The authors conducted confirmatory factor analyses of reports of posttraumatic stress reactions using a national probability sample of individuals indirectly exposed to the terrorist attacks of September 11, 2001 (n = 675). Reactions at three time points in the year after the attacks were best accounted for by a lower-order, 4-factor solution (Reexperiencing, Strategic Avoidance, Emotional Numbing, and Hyperarousal Symptoms). Indirect exposure to a traumatic event appears to induce a response with a similar symptom structure as responses to direct exposure
