Objective: The purpose of this study was to determine how sleep quality affects cognitive functioning in returning combat veterans after accounting for effects of combat exposure, posttraumatic stress disorder (PTSD), and mild traumatic brain injury (mTBI) history. Method: This was a cross-sectional assessment study evaluating combat exposure, PTSD, mTBI history, sleep quality, and neuropsychological functioning. One hundred and nine eligible male Iraq/Afghanistan combat veterans completed an assessment consisting of a structured clinical interview, neuropsychological battery, and self-report measures. Results: Using partial least squares structural equation modeling, combat experiences and mTBI history were not directly associated with sleep quality. PTSD was directly associated with sleep quality, which contributed to deficits in neuropsychological functioning independently of and in addition to combat experiences, PTSD, and mTBI history. Combat experiences and PTSD were differentially associated with motor speed. Conclusions: Sleep affected cognitive function independently of combat experiences, PTSD, and mTBI history. Sleep quality also contributed to cognitive deficits beyond effects of PTSD. An evaluation of sleep quality may be a useful point of clinical intervention in combat veterans with cognitive complaints. Improving sleep quality could alleviate cognitive complaints, improving veterans’ ability to engage in treatment.
