National trends in mental health outcomes among U.S. combat veterans by war era.

U.S. combat veterans are at elevated risk for adverse mental health outcomes, yet contemporary, nationally representative data across war eras is limited. We analyzed data from the 2025-2026 National Health and Resilience in Veterans Study (NHRVS; total N = 2636), which surveyed a contemporary, nationally representative sample of Vietnam War (n = 404, weighted 33.9%), Gulf War (n = 186, weighted 20.1%), and Iraq/Afghanistan War veterans (n = 341, weighted 45.7%) and compared findings with the 2019-2020 NHRVS cohort. Results revealed that Gulf War and Iraq/Afghanistan veterans were younger, more racially and ethnically diverse, and more likely to have completed college than Vietnam War veterans. Iraq/Afghanistan veterans reported higher rates of deployment-related injuries, and military sexual trauma, and had the highest prevalence of lifetime posttraumatic stress disorder (PTSD), depression, and anxiety disorders, followed by Gulf War veterans and Vietnam War veterans. Similarly, current psychiatric disorders, including PTSD, depression, generalized anxiety disorder (GAD), alcohol use disorder, and suicidal ideation, were most prevalent among Iraq/Afghanistan and Gulf War veterans, who were also more likely to utilize mental health services. Compared with the 2019-2020 cohort, the 2025-2026 cohort had a higher prevalence of GAD (1.9% to 5.1%; p = 0.002), and suicidal ideation (4.9% to 8.6%; p = 0.012) among Vietnam War veterans, and PTSD among Iraq/Afghanistan War veterans (14.7% to 21.9%; p = 0.025). These findings highlight marked war-era differences and emerging increases in psychiatric burden among Vietnam and Iraq/Afghanistan-era veterans, with implications for targeted prevention, clinical care, and policy planning for U.S. combat veterans.