FORT BENNING, GA — Lack of sleep has long been a feature of military service. Operational demands, military culture and medical disorders each play a role, but new research indicates an unexpected sleep problem significantly contributes to the shuteye shortage—nightmares.

Nearly a third of servicemembers referred for sleep disturbances experienced nightmares at least once a week, and 60% of those had trauma-related nightmares, according to a study published in the March issue of the Journal of Clinical Sleep Medicine. Less than 4% of military personnel reported nightmares as a concern that warranted evaluation, however.1

Most people have the occasional nightmare, a disturbingly vivid dream that involves threats to survival or security. In individuals with nightmare disorder, those dark and frightening dreams occur repeatedly and cause clinically significant distress or impair functioning during waking hours. During trauma-related nightmares, sleepers may relive a traumatic event or some of its elements.

“Nightmare disorder is highly prevalent but under-recognized in military personnel with sleep disturbances,” said lead researcher Jennifer Creamer, MD, chief of the Sleep Medicine Center at Martin Army Medical Center in Fort Benning, GA.

The presence of nightmare disorder also substantially elevated the risk of other issues associated with sleep disturbances. Patients with nightmare disorder were twice as likely to have suffered traumatic brain injury and five times as likely to have post-traumatic stress disorder as those without clinically significant nightmares. They also had a 355% increased relative risk of depression, 257% increased relative risk of anxiety and 159% increased relative risk of insomnia compared to those with sleep disturbances but without frequent nightmares. Patients with nightmare disorder had shorter sleep duration and took longer to fall asleep.

Relationship to Trauma

Looking deeper, the researchers found that the group with trauma-related nightmares accounted for most of the increase in the rates of TBI, anxiety, depression and PTSD between participants with nightmare disorder and those without it. Among those with nightmare disorder, the participants with trauma-related nightmares had nearly six times the rate of TBI, more than five times the rate of PTSD and twice the rate of anxiety and depression compared to those who had other types of nightmares.

The retrospective study included 500 active duty U.S. military personnel referred to an academic sleep disorders center for evaluation of sleep disorders between January 2016 and December 2016. Their records were pulled randomly from the 2,500 evaluations conducted at the center that year. Participants came from all branches, with 45.6% serving in the Army, 45.2% in the Air Force and 9.2 in the Navy or Marines. Almost three-quarters had been deployed, and 78.5% were male.

Participants completed a self-report questionnaire that included multiple sleep assessments, as well as medical and military history sections. Patients were asked whether and where they had deployed and whether they used a range of sleep aids. All participants had an in-laboratory diagnostic polysomnogram.

Researchers said the scope of the problem was somewhat unexpected. “We see nightmares as underreported due to a lack of awareness by medical providers as to how frequently they occur and that they are present in patients without PTSD,” Creamer told U.S. Medicine. “Another reason is that military personnel are less likely to report nightmares (particularly trauma-related nightmares), given their association with PTSD, stigma and potential career implications.”

Servicemembers also might not report recurrent, disruptive nightmares because they are unaware that therapy exists for these dysphoric dreams. “Either medical therapy with prazosin or behavioral therapy with Imagery Rehearsal Therapy can improve nightmares,” Creamer said.

About 60% of the active duty personnel evaluated had trauma-related nightmares, which “tend to be more severe and distressing than idiopathic nightmares,” the researchers said. Trauma-related nightmares occur in up to 80% of individuals who have PTSD and typically begin within three months of a trauma; they may persist for life, if untreated.

The researchers suggested that, among servicemembers, “nightmares are expected or even perceived as normal after trauma.” In the study, individuals who had trauma-related nightmares were 50% more likely to have deployed.

“Given the high rates of [trauma-related nightmares] and their noted persistence over time, specifically addressing this disorder in close temporal proximity to the traumatic experience has the potential to improve not only nightmare-associated distress but overall sleep quality,” the authors wrote. They found that servicemembers with trauma-related nightmares had worse symptoms of insomnia and sleep efficiency.

“Military personnel and healthcare providers require education that nightmares are not normal and there are treatments available,” Creamer said. “Treatment of nightmares can lead to improvement in sleep, quality of life and other disorders, such as suicidality,” she said.

Previous studies have found that “nightmares are an independent risk factor for suicide and are associated with a fivefold increase in suicidality,” the researchers noted.

Given the serious sequelae of nightmares, Creamer recommended that clinicians screen servicemembers and veterans who have been exposed to traumatic events. Adopting a systematic approach to evaluating nightmares in all patients with sleep disturbance will likely also improve identification of individuals with this nocturnal disorder, as the study found few servicemembers report nightmares as a sleep-related concern.

“Options include using the Pittsburgh Sleep Quality Index which specifically asks about bad dreams or just asking patients if they have nightmares,” she said. “However, it is likely a written (i.e., questionnaire-based approach) and clinical interview combined which have the best results as some patients seem more likely to write about nightmares.”

1Creamer JL, Brock MS, Matsangas P, Motamedi V, Mysliwiec V. Nightmares in United States Military Personnel With Sleep Disturbances. J Clin Sleep Med. 2018 Mar 15;14(3):419-426.