Examining The Relationship Between Sleep And Mental Health Symptoms Across Multiple Deployments In U.S. Military Service Members

Background: Military service members are frequently subjected to occupational and environmental stressors, including non-conducive sleeping environments, shift schedules, and extended deployments overseas. Service members who undergo deployments in particular are at increased risk for mental health symptoms and sleep disturbance. Bidirectional relationships between sleep and mental health are routinely observed, in which poor sleep can increase risk for mental health symptoms, and psychiatric disorders increase risk of developing sleep disturbance; thus, the military population are at elevated risk for both types of problems, given the commonality of repeated and extended deployments. The purpose of the present study was to examine temporal relationships between sleep and mental health symptoms (PTSD, depression, and anxiety) in military service members across the deployment cycle. Methods: Data from 74 U.S. Army soldiers or activated reserve/U.S. National Guard members case-matched across three time points were used for this study. All participants completed at least one 12-month deployment, with the majority undergoing multiple deployments. Symptoms of PTSD, anxiety, depression, and insomnia were assessed at all three time points. Results: Cross-lagged hierarchical regression models revealed that, the presence of mental health symptoms (specifically PTSD) predicted subsequent insomnia symptoms, whereas initial symptoms of insomnia did not predict any subsequent mental health outcomes. However, the persistence of insomnia symptoms across the time points served to be the stronger predictor of subsequent mental health symptoms (specifically PTSD and anxiety) versus the inverse relationship (i.e., persistent mental health symptoms predicting subsequent insomnia symptoms). Conclusions: The present findings suggest differential associations between sleep and mental health, depending on the chronicity of symptoms. Specifically, chronic as opposed to transient symptoms of insomnia pose a more significant risk factor for the development of PTSD and anxiety. Given the high stress associated with undergoing military deployments, service members may be more susceptible to sleep-onset difficulties due to heightened vigilance, which may in turn lead to increased risk for hyperarousal-related psychopathology. These results highlight a potential target in preventing the onset of these conditions.