The effects of initial trauma exposure on the symptomatic response to a subsequent trauma

The effect of initial trauma on the symptomatic response to a subsequent tr auma was investigated in a cross-sectional study of urban bus drivers. Comp arisons were made among 175 drivers who had developed either high or low sy mptoms of post-traumatic stress disorder (PTSD) as a result of the initial trauma, and a third group exposed to only a single trauma. The group with h igh levels of PTSD symptoms after the initial trauma reported high PTSD sym ptoms for a subsequent trauma (75%) significantly more often than the other two groups who did not differ from each other (Low PTSD symptoms group 49% , No prior trauma group 41%). These results suggest that unless trauma expo sure leads to significant PTSD symptoms, it is not a risk factor for high P TSD symptoms after exposure to a subsequent traumatic event.