Sleep moderates symptom experience in combat veterans

Background: Though sleep disturbance has shown to negatively affect outcomes related to post-deployment conditions, it is unclear whether and how sleep disturbance affects mental health symptoms beyond these conditions. We evaluated the independent and moderating effects of sleep quality on posttraumatic stress disorder (PTSD), depressive, and neurobehavioral symptoms beyond mild traumatic brain injury (TBI) and PTSD diagnosis. Methods: Participants were 274 US combat veterans who deployed after 9/11. All completed diagnostic TBI and PTSD interviews and self-report measures of sleep quality, as well as PTSD, depressive, and neurobehavioral symptoms. Only those who passed symptom validity were included in analyses. Hierarchical regression evaluated the contribution of sleep quality to outcomes beyond PTSD and mild TBI. Moderation analyses evaluated interactions between mild TBI, PTSD, and sleep quality on symptom outcomes. Results: Mild TBI was only significantly associated with PTSD (p = .006) and neurobehavioral (p = .003) symptoms. PTSD diagnosis was associated with PTSD (p < .001), depressive (p < .001), and neurobehavioral symptoms (p < .001) beyond mild TBI. Sleep quality explained additional significant variance in all three outcome measures (p < .001), and also significantly moderated the effects of PTSD diagnosis on neurobehavioral symptoms (Delta R-2 = .01, p = .023). Limitations: Sleep was evaluated subjectively and therefore must be interpreted in this context. Conclusions: These results provide support that sleep quality is an independent contributing factor to health outcomes in post-deployment veterans and should be considered in etiology of complaints.

Automated summary

Sleep quality plays an independent role in affecting health outcomes in post-deployment veterans, beyond mild traumatic brain injury (TBI) and PTSD diagnosis. It not only contributes to PTSD and neurobehavioral symptoms, but also moderates the effects of PTSD diagnosis on neurobehavioral symptoms.