Vicarious stress: patterns of disturbance and use of mental health services by those indirectly affected by the Oklahoma City bombing.

This study explored the intermediate psychological effects of terrorism on adults not directly affected by the Oklahoma City bombing by examining the course of PTSD and subthreshold PTSD symptoms over time and whether treatment affected this course. The respondents were interviewed at 3-mo. intervals for 18 mo. following an initial 6-mo. survey. Analysis suggested avoidance, re-experiencing, and increased arousal symptoms in this population were limited over time, declining with or without treatment between 6 and 9 mo. Conversely, victimization symptoms remained high without mental health intervention for the first year after the disaster. The study also examined the nature and occurrence of comorbidity in groups seeking and not seeking treatment.