Posttraumatic stress disorder and depression trends from 2001 to 2021 among post-9/11 veterans in the U.S. Millennium...

Approximately one in five veterans may develop a mental health condition, though longitudinal prevalence estimates among post-9/11 veterans are limited. This study examined two decades (2001-21) of posttraumatic stress disorder (PTSD) and depression data from the Millennium Cohort Study. Eligible participants were actively serving at baseline and separated before the 2019-21 follow-up survey (n = 133,575). Probable PTSD (PTSD Checklist) and depression (Patient Health Questionnaire) were assessed. Age- and sex-standardized prevalence estimates for PTSD, depression, and co-occurring PTSD/depression (a four-level, mutually exclusive variable) were calculated for six time points. PTSD increased approximately five-fold (5.2 to 25.2 cases/100 persons) and depression four-fold (3.6 to 15.5 cases/100 persons). For the co-occurring PTSD/depression outcome, a two-fold increase was observed for depression only (1.5 to 2.7 cases/100 persons), while increases for PTSD only (3.1 to 12.4 cases/100 persons), and comorbid PTSD/depression (2.0 to 12.7 cases/100 persons) were four- and six-fold, respectively. In this population-based study, prevalence estimates of PTSD and depression increased over time, with larger increases attributable to PTSD and co-occurring PTSD/depression. These pronounced increases in prevalence estimates warrant consideration for expansion of mental health screening and treatment services among post-9/11 veterans.