Abstract: Objective To explore the relationship between insomnia,rumination and depression in clinical nurses,and analyze the effect of rumination on insomnia and depression. Methods From August to October 2023,631 clinical nurses from a grade-A tertiary hospital in Anhui Province were randomly selected as the investigation objects. General information questionnaire,self-rating depression scale,insomnia severity index scale and rumination response scale were used to investigate,and the data were analyzed. Results The prevalence rate of depression among clinical nurses in agrade-A tertiary hospital in Anhui Province was 56.6%. There were statistically significant differences in depression scores among clinical nurses of different ages,professional title,length of service,and whether they were engaged in nursing research work（all P<0.05）. The difference in insomnia scores between clinical nurses who worked in nursing research and those who did not was statistically significant（P<0.05）. The higher the degree of depression,the higher the scores of insomnia（F=88.200,P<0.01） and rumination thinking（F=60.129,P<0.01）,and depression was positively correlated with insomnia and rumination thinking（r=0.567,0.527,both P<0.01）. The structural equation model showed that the direct effect of insomnia on depression was 0.753,and the indirect effect was 0.292. The higher the insomnia score,the higher the depression score,and insomnia positively predicted depression. Rumination had a significant indirect effect on depression through insomnia（B=0.416,95%CI：0.626-0.880）,and rumination had a partial mediating effect between insomnia and depression,accounting for 27.9% of the total effect. Conclusion Insomnia and ruminative thinking are the factors that cause depression in clinical nurses. Insomnia can act on depression through direct and indirect pathways,and ruminative thinking plays a part of mediating role.

Key words: Nurse, Depression, Insomnia, Rumination, Mediating role