COVID stress and depressive symptoms among high school students: a moderated mediation model of sleep quality and optimism

PurposeThis study aimed to investigate whether optimism buffers an indirect relationship between COVID stress and depressive symptoms via poor sleep quality among Vietnamese high school students.Design/methodology/approachSix hundred and eighty-five participants completed the Coronavirus Stress Measure, the Life Orientation Test-Revised, the Pittsburgh Sleep Quality Index and the Depression, Anxiety and Stress Scales. Process Macro 3.5 for SPSS (Model 4 and Model 14) was used to analyze the mediating effect and moderated mediation effect.FindingsThe results indicated that COVID stress was associated with an increase in depressive symptoms via the indirect pathway of poor sleep quality. Furthermore, optimism moderated the indirect relationship between COVID stress and depressive symptoms through poor sleep quality among Vietnamese students.Originality/valueThe study's findings may serve as a basis for the development of depression prevention interventions for students with high COVID stress in the COVID-19 pandemic.