Sleep Symptoms as a Partial Mediator Between Combat Stressors and Other Mental Health Symptoms in Iraq War Veterans

Abstract: Sleep symptoms are a prominent feature of mental health disorders like PTSD and depression. However, it is unknown whether sleep symptoms mediate the relationship between combat stress and these disorders. We examined the mediating role of sleep symptoms on the relationship between combat stress and PTSD; and the relationship between combat stress and depression using data from 576 Army veterans of the Iraq War surveyed in 2004. Correlational analyses revealed that when insomnia was included in the model, the correlation between combat stressors and other depression symptoms decreased by 65%; and when nightmares were included in the model, the correlation between combat stressors and other PTSD symptoms decreased by 69%. We replicated these analyses using individual items assessing PTSD and depression and found that the insomnia and nightmare items had the largest and second largest mediation effect between combat stressors and PTSD and depression symptoms. Our result support the theory that sleep symptoms contribute to the development and/or maintenance of other mental health symptoms and that early treatment of sleep symptoms may mitigate the other mental health consequences of combat stress.