A new study out of the University of California, San Francisco, and the San Francisco Veterans Affairs Healthcare System investigated the increased risk of sleep disorders following traumatic brain injury.

In this study, the researchers performed a cohort study of all patients diagnosed with a traumatic brain injury in the Veterans Health Administration system from 2001 to 2015. These patients were aged-matched with veterans who had not sustained a traumatic brain injury. Any veteran who had a prevalent sleep disorder at the baseline was excluded from the study. The disorders were defined as any inpatient or outpatient diagnosis of sleep apnea, hypersomnia, insomnia, or sleep-related mood disorders. The researcher’s analysis was restricted to those for at least one year.

Out of the approximately 200,000 veterans included in the study, those who had a traumatic brain injury compared to those without were 41% more likely to develop a sleep disorder. Most importantly, the researchers found that the association was stronger for mild TBI’s, did not differ appreciably by the presence of post-traumatic stress disorder and remained after a 14 year time lag.

The researchers concluded, “in 197,418 veterans without sleep disorders those with diagnosed TBI had an increased risk of incident sleep disorders over 14 years.” The study also demonstrated that patients with traumatic brain injuries were more likely than those without to have psychiatric conditions including mood disorders, anxiety, PTSD, and substance abuse.