Relationship between perceived stress and depression in Chinese front-line medical staff during COVID-19: A conditional process model.

Background: Sustained stress during COVID-19 may be associated with depression in front-line medical staff, which would expose them to severe threats. This study aimed to examine whether the relationship between perceived stress and depression is mediated by insomnia, and whether this mediation is moderated by resilience.

Methods: For front-line medical staff, this study used online questionnaire to evaluate their perceived stress, depression, insomnia and resilience. A conditional process model was performed to examine the relationship between perceived stress and depression, as well as the mediating effect of insomnia and the moderating effect of resilience.

Results: A total of 606 front-line medical staff completed the survey. Higher level of perceived stress was significantly positively related to severe insomnia and depression. In addition, insomnia was positively related to depression, while resilience could moderate the effect of perceived stress on depression by direct and indirect paths.

Limitations: The causality among perceived stress, depression, insomnia and resilience is difficult to be verified.

Conclusions: Perceived stress is positively related to depression, and insomnia can mediate the effect of perceived stress on depression. In addition, the effect of perceived stress on depression, whether direct or indirect, is moderated by resilience, which is a protective factor for mental health.