Predeployment sleep duration and insomnia symptoms as risk factors for new-onset mental health disorders following military deployment

Study Objectives: To evaluate predeployment sleep duration and insomnia symptoms in relation to the development of mental health symptoms. Design: Longitudinal cohort study. Setting: The Millennium Cohort Study survey is administered via a secure website or US mail. Participants: Data were from 15,204 participants who completed their first deployment between the submissions of 2 consecutive Millennium Cohort questionnaires (2001-2008). Interventions: N/A. Measurements and Results: Using self-reported data from the Millennium Cohort Study we evaluated the association of predeployment sleep duration and insomnia symptoms on the development of new-onset mental disorders among deployers. Multivariable logistic regression was used to estimate the odds of developing posttraumatic stress disorder (PTSD), depression, and anxiety, while adjusting for relevant covariates including combat-related trauma. The study outcomes were assessed using validated instruments, including the PTSD checklist-civilian version, and the PRIME-MD Patient Health Questionnaire. We identified 522 people with new-onset PTSD, 151 with anxiety, and 303 with depression following deployment. In adjusted models, combat-related trauma and predeployment insomnia symptoms were significantly associated with higher odds of developing posttraumatic stress disorder, depression, and anxiety postdeployment. Conclusions: Sleep characteristics, especially insomnia symptoms, are related to the development of mental disorders following military deployments. Assessment of insomnia symptoms predeployment may help to better identify those at highest risk for subsequent adverse mental health outcomes.