Shift work is an integral part of living in a 24-hour society. However, shift work can disrupt circadian rhythms, negatively impacting health. Guided by the Stress Process Model (SPM), this study examines the association between shift work and depressive symptoms and investigates whether sleep health (duration, quality, and latency) mediates this relationship among midlife adults. Utilizing data from the National Longitudinal Survey of Youth 1979 cohort (N = 6,372), findings show that working evening, night, and irregular shifts is associated with increased depressive symptoms. The results also show that part of the association between shift work and depressive symptoms among night and irregular shift workers, is indirect, operating through short sleep during the week and on the weekend. Although shift work can negatively affect mental health, getting more restorative sleep may mitigate part of the harmful mental health consequences of non-standard work schedules.
Keywords: depressive symptoms; shift work; sleep; stress process.