"In this study, the highest levels of comorbidity (six or more comorbid conditions) among veterans were observed among treatment seekers. However, only those with comorbid DUD [Drug Use Disorders] were significantly more likely to seek treatment for PTSD once potentially confounding factors were accounted for. It is of concern that, in the present sample, 32% of veterans with PTSD who did not seek treatment had 6+ comorbid conditions.

"Overall, the prevalence of 6.3% for lifetime DSM-5 PTSD in U.S. veterans is lower than that reported in previous studies of era-specific (18.7% and 52%) (Dohrenwend et al., 2007; Ikin et al., 2010; Jakupcak et al., 2010) veteran cohorts but similar to a national sample of veterans (7.95%; Wisco et al., 2014) using previous diagnostic classifications. In part this may reflect the narrow definition used in the study. However, the lifetime prevalence of PTSD among veterans in this study was very similar to the prevalences of 6.4% and 7.8% reported for DSM-IV PTSD in the general U.S.