Changing prevalence of psychosocial occupational stressors and their impact on employee mental health across birth cohorts.

Background: Mental illness is the leading cause of employee absence and vocational disability in many countries. The Job Demand-Control model posits that risk factors for mental illness include psychosocial stressors such as high job demands and low job control. We determined (1) if the prevalence of population-level work-related risk factors has changed over time (workplace change) and (2) whether the strength of the association between risk factors and mental health has changed over time (workforce change).

Methods: Using a nationally representative Australian longitudinal panel survey (N=19 499), we estimated the linear trend in prevalence of psychosocial stressors between 2001 and 2020. The strength of the association (marginal effects) of psychosocial stressors with mental health was calculated and differences between birth cohorts were tested.

Results: Over two decades, the population prevalence of high job demands increased (B_year (95% CI) = 0.017 (0.014, 0.021)); while there was no trend in low job control (B_year (95% CI) = 0.001 (-0.002, 0.004)). Moreover, the negative effect of job demands (highly stressful or potentially illness inducing) on mental health was greater in the youngest cohort (B_1990s-1980s(SE)=-0.21 (0.08), and -0.41 (0.09), while the benefit of control (having a lot of say at work) was less (B_1990s-1980s(SE)=-0.35 (0.07)).

Conclusion: Not only do employees increasingly view work as demanding, but the negative impact of this on younger employee mental health is greater, while younger workers benefit less from workplace autonomy than previous cohorts. These findings, compounding mental health trends in adolescents, will result in younger generations of employees at greater risk of mental illness unless employers, insurers and regulators adapt.