The impact of sleep quality on mental health in working Australians: A quasi-experimental approach

Abstract Work conditions such as job demand can impact individual sleep quality, and subsequently impact mental health. This study aims to investigate pathway effects of exogenous factors on mental health via sleep, and the direct effect of sleep quality on mental health in working Australians. We employ a novel method in public health studies, a quasi-experimental (instrumental variable) approach, which can address reciprocal relationships between sleep and mental health in order to estimate causal effect of sleep quality on mental health in a sample of 19,789 working Australians aged 25-64 from waves 2013, 2017, and 2021 of the Household, Income and Labour Dynamics in Australia (HILDA) survey data. We find that high job demand, as a valid instrument, adversely affects sleep quality, and the changes in sleep quality ultimately affect mental health of working Australians. These findings highlight the need for policies that address employment conditions by reducing high work demand or workload to mitigate poor sleep quality in the Australian workforce, ultimately improving workers' sleep quality and promoting better mental health, overall health outcomes and productivity.