Nichter B, et al. - In view of evidence suggesting a high-risk for poor mental health among veterans with co-occurring PTSD/MDD vs those with PTSD alone, researchers sought to provide a population-based characterization of sociodemographic, risk, and protective variables associated with comorbid PTSD/MDD among U.S. military veterans. From the National Health and Resilience in Veterans Study, a nationally representative survey of U.S. military veterans (n = 2,732), veterans with PTSD alone and co-occurring PTSD/MDD were compared in terms of sociodemographic, military, and psychosocial characteristics. The analysis revealed PTSD/MDD status in positive correlation to racial/ethnic minority status, number of lifetime traumas, and time spent engaged in private religious/spiritual activities and in negative correlation to higher scores on measures of community integration and dispositional optimism. The largest proportions of variance in PTSD/MDD comorbidity seemed to be related to dispositional optimism (34%) and community integration (24%). Findings highlight the necessity to study whether clinical outcomes in this population could be improved via targeting dispositional optimism and community integration in prevention and treatment efforts.