Posttraumatic Stress Disorder and Incident Infections: A Nationwide Cohort Study

It is unknown whether posttraumatic stress disorder (PTSD) is associated with incident infections. This study's objectives were to examine (1) the association between PTSD diagnosis and 28 types of infections and (2) the interaction between PTSD diagnosis and sex on the rate of infections.

The study population consisted of a longitudinal nationwide cohort of all residents of Denmark who received a PTSD diagnosis between 1995 and 2011, and an age- and sex-matched general population comparison cohort. We fit Cox proportional hazards regression models to examine associations between PTSD diagnosis and infections. To account for multiple estimation, we adjusted the hazard ratios (HRs) using semi-Bayes shrinkage. We calculated interaction contrasts to assess the presence of interaction between PTSD diagnosis and sex.

After semi-Bayes shrinkage, the HR for any type of infection was 1.8 (95% confidence interval: 1.6, 2.0), adjusting for marital status, non-psychiatric comorbidity, and diagnoses of substance abuse, substance dependence, and depression. The association between PTSD diagnosis and some infections (e.g., urinary tract infections) were stronger among women, whereas other associations were stronger among men (e.g., skin infections).

This study's findings suggest that PTSD diagnosis is a risk factor for numerous infection types and that the associations between PTSD diagnosis and infections are modified by sex.