A study found a six-fold increase in the age-adjusted prevalence of any sleep disorder diagnosis over an 11-year period among US veterans. The largest increases were identified in patients with post-traumatic stress disorder (PTSD), other mental disorders, or combat experience. Results also show that the prevalence of PTSD tripled during the study period.

In a sample of more than 9.7 million US veterans, the age-adjusted prevalence of sleep disorders increased from less than 1% in 2000 to nearly 6% in 2010. Sleep apnea was the most common sleep disorder diagnosis (47%) followed by insomnia (26%). Veterans with cardiovascular disease, cancer, or other chronic diseases also experienced higher rates of sleep disorder diagnoses relative to those without comorbid conditions.

Study results are published in the July issue of the journal Sleep.

“Veterans with PTSD had a very high sleep disorder prevalence of 16%, the highest among the various health conditions or other population characteristics that we examined,” says principal investigator and senior author James Burch, PhD, associate professor in the Department of Epidemiology and Biostatistics in the Arnold School of Public Health at the University of South Carolina, in a release. “Because of the way this study was designed, this does not prove that PTSD caused the increase in sleep disorder diagnoses.” Burch is also a Health Science Specialist at the WJB Dorn Department of Veterans Affairs Medical Center in Columbia, SC. “However, we recently completed a follow-up study, soon to be submitted for publication, that examined this issue in detail. In that study, a pre-existing history of PTSD was associated with an increased odds of sleep disorder onset,” he says.

The study population consisted of all US veterans seeking care in the Veterans Health Administration system between FY2000 and FY2010. Of the total sample of 9,786,778 veterans, 93% were men, and 751,502 were diagnosed with at least one sleep disorder.