Written by Will Thurston Class of ’19
Sleep is vital to well-being, and many individuals struggle to get the recommended 8 hours of quality rest each night. For individuals with posttraumatic-stress disorder (PTSD) and mild traumatic brain injuries (mTBI), high-quality sleep is both more difficult to achieve and more important for well-being. Researchers have investigated the relationships between sleep quality and cognitive functioning in military veterans, accounting for the effects of combat exposure, PTSD and mTBI (Martindale, Morissette, Rowland, Dolan, 2017). The authors of this study hypothesized that sleep quality would affect cognitive functioning, even when controlling for the effects of other variables.
The study used a sample of 109 Iraq/Afghanistan combat veterans. The veterans were assessed with a number of measures, including an interview to check for symptoms of mental illnesses including PTSD, a measure to assess the number of combat experiences each veteran had experienced, an mTBI screening, and a measure of sleep quality. The veterans also took a series of cognitive tests, which measured abilities such as memory, attention, learning and processing speed. Two-thirds of the sample met criteria for PTSD, and about half met criteria for mTBI history. The average number of combat experiences was 39.95, and almost all of the veterans reported serious sleep problems. The researchers took this data and looked at the relationships between sleep quality and PTSD, mTBI, and combat experiences.
The study found that lower sleep quality reduced the cognitive functioning of the veterans in addition to the other three variables. PSTD, combat experiences and mTBI all contributed to worse sleep quality, and combat experiences directly worsened cognition. These findings show complex relationships between the variables, but an important take-away is that sleep quality is a key factor in the equation. The researchers suggest that focusing on improving sleep might help veterans complete the cognitive tasks required as a part of treatment for PTSD or other combat-related disorders.
Martindale, S. L., Morissette, S. B., Rowland, J. A., & Dolan, S. L. (2017). Sleep quality affects cognitive functioning in returning combat veterans beyond combat exposure, PTSD, and mild TBI history. Neuropsychology, 31(1), 93-104. doi:10.1037/neu0000312