Nightmares in United States Military Personnel With Sleep Disturbances

Study Objectives: Sleep disturbances are common in United States military personnel. Despite their exposure to combat and trauma, little is known about nightmares in this population. The purpose of this study was to describe the prevalence and associated clinical and polysomnographic characteristics of nightmares in United States military personnel with sleep disturbances. Methods: Retrospective review of 500 active duty United States military personnel who underwent a sleep medicine evaluation and polysomnography at our sleep center. The Pittsburgh Sleep Quality Index and the Pittsburgh Sleep Quality Index-Addendum were used to characterize clinically significant nightmares. Subjective and objective sleep attributes were compared between groups. Results: At least weekly nightmares were present in 31.2%; yet, only 3.9% reported nightmares as a reason for evaluation. Trauma-related nightmares occurred in 60% of those patients with nightmares. Patients with nightmares had increased sleep onset latency (SOL) and rapid eye movement (REM) sleep latency (mean SOL/REM sleep latency 16.6/145 minutes, P =.02 and P =.01 respectively) compared to those without (mean SOL/REM sleep latency 12.5/126 minutes). The comorbid disorders of depression (P =.01, relative risk [RR] 3.55 [95% CI, 2.52-4.98]), anxiety (P =.01, RR 2.57 [95% CI, 1.93-3.44]), posttraumatic stress disorder (P =.01, RR 5.11 [95% CI, 3.43-7.62]), and insomnia (P =.01, RR 1.59 [95% CI, 1.42-1.79]) were all associated with nightmares. Conclusions: Clinically significant nightmares are highly prevalent in United States military personnel with sleep disturbances. Nightmares are associated with both subjective and objective sleep disturbances and are frequently comorbid with other sleep and mental health disorders.