Posttraumatic Stress Disorder and Its Associations With Sexually Transmitted Infections Among Veterans.

Background: One-quarter of all veterans who deployed to Iraq and Afghanistan post-9/11 developed posttraumatic stress disorder (PTSD). No known longitudinal study has examined the associations between PTSD and sexually transmitted infections (STIs). Objectives were to (1) examine trends in incidences of PTSD and STIs, (2) estimate the associations between individually measured assessments of PTSD and STI incidence, (3) measure effect modification by deployments and combat exposure, and (4) explore time-varying associations.

Methods: In this prospective cohort study of all veterans who deployed to Iraq and Afghanistan in 2001 to 2022 and receive care in the Department of Veterans Affairs (n = 1,570,654), patients contributed a total of 15,535,454 person-years of follow-up. Joinpoint regression models, marginal structural Poisson models, and marginal structural shared frailty models were fitted with a time-dependent exposure, adjusted for time-independent and time-dependent confounding and informative censoring.

Results: Incidences in PTSD, hepatitis C virus, and human papillomavirus significantly decreased, but those of chlamydia, human immunodeficiency virus, and syphilis significantly increased. Posttraumatic stress disorder was associated with increased rates (adjusted rate ratio, 95% confidence interval) of HPV by 3% (1.03 [1.00-1.05]), human immunodeficiency virus by 8% (1.08 [1.02-1.15]), hepatitis B virus by 9% (1.09 [1.01-1.18]), genital HSV by 9% (1.09 [1.07-1.11]), syphilis by 11% (1.11 [1.05-1.17]), chlamydia by 20% (1.20 [1.17-1.24]), gonorrhea by 21% (1.21 [1.13-1.31]), and hepatitis C virus by 69% (1.69 [1.62, 1.77]), and remained statistically significant.

Discussion: Posttraumatic stress disorder was associated with increased rates of all STIs, and these associations did not diminish with time. Results may help guide preventive efforts and medical decisions for those with PTSD.