PTSD Nearly Doubles Infection Risk.

Having post-traumatic stress disorder (PTSD) nearly doubles a person’s risk of infections, according to a first-of-its-kind School of Public Health study.

Published in the journal Epidemiology, the study is the first to examine the relationship between PTSD and dozens of infection types in a nationwide cohort. It is also the first to find that PTSD affects infection risks for men and women differently, having, for example, more of an effect on a woman’s risk of urinary tract infection and a man’s risk of skin infection.

“Our study adds to the growing evidence suggesting that PTSD and chronic severe stress are damaging for physical health,” says doctoral candidate Tammy Jiang, who led the study.

The researchers used Danish national records to look at the health histories of every Danish-born Danish citizen who received a PTSD diagnosis from 1995 through 2011, and matched each person with a comparison group of Danes of the same sex and age. While previous studies have looked at the relationship between PTSD and one or two diseases, in this study the researchers looked at the Danes’ histories of hospital care for 28 different kinds of infections.

After adjusting for other physical and mental health diagnoses and for marriage/registered partnership, the researchers found that people with PTSD were 1.8 times as likely to have any infection as those without PTSD. This ranged from being 1.3 times as likely to have meningitis, to 1.7 times as likely to have influenza, to 2.7 times as likely to have viral hepatitis. 

Next, the researchers compared men and women with PTSD. A previous study found no relationship between the sex of a person with PTSD and risk of upper respiratory infection, but the new study found that having PTSD had more of an effect on a woman’s risk of upper respiratory infection—and several other kinds of infection, most notably urinary tract infection—than a man’s risk. Having PTSD also had more of an effect on a man’s risk of certain other kinds of infection, most notably skin infection.

The study’s senior author was Jaimie L. Gradus, associate professor of epidemiology, and the study was co-authored by Henrik T. Sørensen, chair of the Department of Clinical Epidemiology at Aarhus University Hospital in Denmark and adjunct professor of epidemiology at SPH. The other co-authors were Dóra Körmendiné Farkas of Aarhus University, Thomas P. Ahern of the University of Vermont, and Timothy L. Lash of the Emory University Rollins School of Public Health.

—Michelle Samuels