Effects of duration and intensity of psychological stressors on mental health outcomes

Chronic psychosocial stress is a major etiological risk factor for major depressive disorder. The main goal of the present study was to investigate the impact of both the intensity (number of daily stressors or severity of chronic stress) and the duration (daily vs chronic) of different stressors on mental health outcomes in healthy adults. One hundred and forty participants were recruited for this study. We measured recent daily stressors, chronic stress level, perceived stress level, and history of childhood maltreatment. Both direct and indirect effects between different stressors and mental health outcomes were analyzed using correlational analysis and structural equation modeling. We found that the duration of stressors was a much stronger predictor of the severity of depression than their intensity, whilst for anxiety both daily and chronic stressors had a stronger impact compared to perceived stress level. Chronic stress level, rather than daily stressors or perceived stress, was the strongest predictor of general distress, depression, and anxiety, whilst both daily and chronic stressors mediated the relationship between childhood maltreatment and mental health outcomes. Our results emphasize the unique role of chronic stress in the development of depression and confirm that the impact of stress on depression is driven by chronic ongoing stress, rather than more recent stressful events or history of childhood maltreatment. These findings suggest that both the duration and intensity of stressors rather than the level of perceived stress alone may have a greater predictive value in determining the effect of stress on anxiety and depression.