The mediating effect of sleep quality on the relationship between social support and depressive symptoms among Chinese nurses during the omicron outbreak

Background The COVID-19 pandemic has led to increased depressive symptoms and diminished sleep quality among nurses. This study explores the relationships among social support, sleep quality, and depressive symptoms among Chinese nurses during the COVID-19 outbreak, with a focus on the mediating role of sleep quality. Methods A cross-sectional study involving 2140 nurses was conducted from August to September 2022. The participants completed the Social Support Rating Scale, the Hospital Anxiety and Depression Scale, and the Pittsburgh Sleep Quality Index. The data were analyzed via serial multiple mediation analysis with the PROCESS macro in SPSS. Results Depressive symptoms affected an estimated 40.4% of the participants, with 69.2% reporting poor sleep quality. The present study revealed a significant negative correlation between social support and sleep quality and depressive symptoms (r = -0.229, p < 0.001; r = -0.322, p < 0.001, respectively). Furthermore, a substantial positive correlation was observed between sleep quality and depressive symptoms (r = 0.514, p < 0.001). Additionally, social support had a significant indirect effect on depressive symptoms through sleep quality (standardized effect = -0.0535, 95% CI = [-0.0648, -0.0424]). Sleep quality was found to mediate the relationship between social support and depressive symptoms in all subgroups, with variations based on years of experience, education levels, and hospital type. Conclusion Depressive symptoms were inversely associated with social support, which was moderated by sleep quality. Interventions targeting social support provision and sleep quality promotion are suggested for managing depressive symptoms among nurses during the COVID-19 pandemic.