It should be noted that adding prior trauma(s) to the equation is unwarranted. Evidence from prospective data shows that prior trauma increased the risk of experiencing a subsequent trauma (Breslau et al. 2008). Additionally, the prospective data show that prior trauma increased the PTSD risk of a subsequent trauma only among those who had suffered PTSD following the prior trauma (Breslau et al. 2008). Similar results were published earlier on acute combat stress reaction (Solomon et al. 1987). The two variables – PTSD (the dependent variable) and prior trauma (a covariate) – are intertwined. Previous research on prior trauma had no information on the PTSD effect of the prior trauma.
