Work stressors, depressive symptoms and sleep quality among US Navy members: a parallel process latent growth modelling approach across deployment

Abstract

The present study examined whether work stressors contribute to sleep problems and depressive symptoms over the course of deployment (i.e. pre-deployment, post-deployment and 6-month reintegration) among US Navy members. Specifically, we examined whether depressive symptoms or sleep quality mediate the relationships between work stressors and these outcomes. Participants were 101 US Navy members who experienced an 8-month deployment after Operational Enduring Freedom/Operation Iraqi Freedom. Using piecewise latent growth models, we found that increased work stressors were linked to increased depressive symptoms and decreased sleep quality across all three deployment stages. Further, increases in work stressors from pre- to post-deployment contributed to poorer sleep quality post-deployment via increasing depressive symptoms. Moreover, sleep quality mediated the association between increases in work stressors and increases in depressive symptoms from pre- to post-deployment. These effects were maintained from post-deployment through the 6-month reintegration. Although preliminary, our results suggest that changes in work stressors may have small, but significant implications for both depressive symptoms and quality of sleep over time, and a bi-directional relationship persists between sleep quality and depression across deployment. Strategies that target both stress and sleep could address both precipitating and perpetuating factors that affect sleep and depressive symptoms.

Keywords: deployment; depression; military members; occupational health; sleep problems.

Figure 1

Standardized results of the parallel-process latent growth model for work stressors, depressive symptoms, and sleep quality (N=101). Significant effects are in bold typeface for emphasis and were determined by a 95% bias-corrected bootstrapped confidence interval (based on 10,000 bootstrapped samples) that does not contain zero. Factor loadings were set to 1 for the intercept to reflect predeployment levels for each construct. Factor loadings were set to 0, 1, and 1 for predeployment, postdeployment, and 6-month reintegration, respectively, for slope 1 to capture growth from predeployment to postdeployment, and were set to 0, 0, and 1 for slope 2 to capture growth from postdeployment to 6-month reintegration. Loadings constrained to 0 for the intercept and slope factors, correlations among errors, and disturbances are not displayed for clarity. CESD=10-item Center for Epidemiological Studies Depression Scale; Sleep=Sleep Quality.

Figure 2

Standardized results of the parallel-process latent growth model for work stressors, sleep quality, and depressive symptoms (N=101). Significant effects are in bold typeface for emphasis and were determined by a 95% bias-corrected bootstrapped confidence interval (based on 10,000 bootstrapped samples) that does not contain zero. Factor loadings were set to 1 for the intercept to reflect predeployment levels for each construct. Factor loadings were set to 0, 1, and 1 for predeployment, postdeployment, and 6-month reintegration, respectively, for slope 1 to capture growth from predeployment to postdeployment, and were set to 0, 0, and 1 for slope 2 to capture growth from postdeployment to 6-month reintegration. Loadings constrained to 0 for the intercept and slope factors, correlations among errors, and disturbances are not displayed for clarity. CESD=10-item Center for Epidemiological Studies Depression Scale; Sleep=Sleep Quality.