Lifetime, past-12-month, and past-6-month prevalence estimates of PTSD using the DSM-5 and current DSM-IV criteria are included in Table 3. Separate prevalence estimates based on Same Event and Composite Event PTSD definitions are included. Only two prevalence comparisons were statistically significant. The prevalence of the DSM-5 lifetime Composite Event PTSD and the prevalence of the DSM-5 past-12-month Same Event PTSD each was significantly lower than the corresponding prevalence according to the DSM-IV. In all other instances, the DSM-5 prevalence estimates were slightly lower, but differences were not statistically significant. Our study’s past-12-month DSM-IV prevalence of 6.3% was also compared with the past-12-month DSM-IV PTSD prevalence of 3.6% reported by Kessler, Chiu, Demler, Merikangas, and Walters (2005). Results indicated that the prevalence of past-12-month DSM-IV PTSD in the present study was significantly higher than the 12-month DSM-IV PTSD prevalence found by Kessler, Chiu, and colleagues (2005; z = −5.79, p < .001).
