Rates and correlates of nightmares and insomnia in active duty military service members pre- and postdeployment.

OBJECTIVE: This study aimed to determine the rates, chronicity, and correlates of nightmares and insomnia, alone and in combination, in U.S. Army personnel at predeployment and postdeployment. METHOD: Service members were assessed prior to (N = 3,952) and following (N = 1,762) a combat deployment between 2010 and 2016. Participants were categorized predeployment into nightmare and insomnia groups using the PTSD Checklist-Military Version distressing dreams item (Item 2 score ≥ 3) and the Insomnia Severity Index (total score ≥ 15). Postdeployment, participants were further classified into 16 groups reflecting the combination of nightmare and insomnia trajectories. RESULTS: Predeployment, 12% of participants were in the nightmares only group, 9% were in the insomnia only group, and 11% were in the both nightmares and insomnia group. Predeployment, the nightmares only group was older, had more deployments, and had greater mental health symptoms than the neither group. The insomnia only group had more deployments and greater mental health symptoms than the neither group. The both nightmares and insomnia group was more likely to identify as Native American, be older, have more prior deployments, and have greater anxiety symptoms than all other groups. Postdeployment, the new-onset trajectory, chronic nightmare trajectory, and chronic insomnia trajectory were generally related to higher posttraumatic stress disorder, anger, and anxiety symptoms compared with the remitted, no nightmares, and no insomnia trajectories. CONCLUSIONS: Nightmares and insomnia, singularly and comorbid, are associated with mental health problems. Transdiagnostic treatments that target both conditions may be an efficient means to ameliorate sleep problems and minimize effects on mental health. (PsycInfo Database Record (c) 2026 APA, all rights reserved).