Effect of perceived stress on insomnia severity among male soldiers: mediating role of depression and moderating role of mindfulness

Abstract

Objective To explore the effect of perceived stress on insomnia severity among male soldiers, and examine the mediating effect of depression and the moderating effect of mindfulness. Methods A sample of 1 321 male soldiers from a unit of the army were investigated with Perceived Stress Scale (PSS), Insomnia Severity Index (ISI), Self-Rating Depression Scale (SDS) and Five Facet Mindfulness Questionnaire (FFMQ) during March 2021. Pearson correlation analysis was employed to analyze the correlation of perceived stress, insomnia severity, depression and mindfulness. PROCESS program was adopted to investigate the mediating role of depression and moderating role of mindfulness. Results ① The incidence rate of insomnia was 11.36% among the male soldiers. The prevalence rate of subthreshold insomnia was 8.86%, of clinical insomnia (moderate severity) was 2.12%, and of clinical insomnia (severe) was 0.38%. The prevalence rate of depression was 15.52% among them. And the prevalence rate of mild depression was 9.16%, of moderate depression was 6.13%, and of major depression was 0.23%. ②PSS score had significant positive correlation with ISI score (r=0.43, P < 0.01), and SDS score was positively correlated with both PSS and ISI scores (r=0.70, 0.42, P < 0.01). FFMQ score was negatively correlated with PSS, SDS and ISI scores (r=-0.39, -0.39, -0.17, P < 0.01). ③The relationship between perceived stress and insomnia severity was partially mediated by depression, accounting for 37.21% of the total effect. ④The effect of perceived stress on depression (β=-0.11, P < 0.01) and effect of perceived stress on insomnia severity (β=-0.05, P < 0.05) were both moderated by mindfulness. Compared with low level of mindfulness, high level of mindfulness could alleviate the adverse impacts of perceived stress on both depression and insomnia severity. Conclusion Perceived stress affects insomnia severity through depression, and mindfulness can mitigate the effects of perceived stress on both depression and insomnia severity. Mindfulness training may help to reduce depression and improve sleep quality of male soldiers.

Keywords

• perceived stress
• insomnia severity
• depression
• mindfulness
• male soldiers