Abstract Introduction Rapid eye movement (REM) sleep behavior disorder (RBD) is a parasomnia strongly associated with α-synucleinopathies, most commonly Parkinson’s disease (PD). Among Veterans, posttraumatic stress disorder (PTSD) is common and may influence RBD presentation and outcomes. The extent to which PTSD modifies demographic, medical, and mortality profiles in Veterans with RBD, and how these differ from those with RBD and Parkinson’s disease (PD), remains poorly characterized. Methods We conducted a retrospective cohort study using the Veterans Health Administration Corporate Data Warehouse. Veterans with at least one ICD-9 or ICD-10 diagnostic code for RBD were identified between 1999 - 2020 and categorized into three, mutually-exclusive groups based on the presence or absence of co-occurring ICD codes: RBD-only, RBD+PTSD, or RBD+PD. Demographics, comorbidities (Charlson Comorbidity Index CCI), and mortality outcomes were compared using logistic regression models adjusted for age, sex, race/ethnicity, BMI, and CCI. Results The cohort included 11,283 Veterans with RBD only, 17,527 with RBD+PTSD, and 5,675 with RBD+PD. Veterans with RBD+PTSD were younger (mean 58.9 ± 14.9 y) and had higher psychiatric comorbidity (94.2%) compared to RBD only (54.2%) or RBD+PD (46.5%). Those with RBD+PD were older (73.6 ± 8.1 y), predominantly male (98.9%), and had the highest neurological comorbidity (92.6%). Unadjusted mortality was lowest in RBD+PTSD (15.3%) and highest in RBD+PD (53.6%). Adjusted models showed reduced mortality risk for RBD+PTSD (aOR 0.73, 95% CI 0.70–0.80, p 0.001) and increased risk for RBD+PD (aOR 2.43, 95% CI 2.3–2.6, p 0.001) vs. RBD alone. Higher age, male sex, and greater comorbidity independently predicted mortality. Conclusion In this large national VA cohort, comorbid PTSD and Parkinson’s disease were associated with distinct demographic and clinical profiles among Veterans with RBD. RBD+PTSD was linked to younger age, greater psychiatric burden, and lower mortality. These findings underscore the heterogeneity of RBD in Veterans and support stratified approaches to surveillance for synucleinopathy and trauma-related sleep disturbances. Support (if any) VA CDA # IK2CX002363-01A1 (MJ); NHLBI K25 #1K25HL152006-01 (JR)
Jones et al. (2026) studied this question.