The impact of night shift workload on nurses’ depressive symptoms: a chain mediation analysis of sleep disturbances, social avoidance and fear of missing out

Background Depression is highly prevalent among nursing staff and has become a globally recognized occupational health issue. Despite its significance, research exploring the complex mechanisms linking night shift work and depressive symptoms in nurses remains limited. Objective This study aims to investigate the association of sleep disturbances, social avoidance and distress (SAD), and fear of missing out (FOMO) with night shift work and depressive symptoms among nurses. Methods Between June and August 2025, clinical nurses from a Grade-A tertiary hospital in Haikou were recruited. Data were collected using a general-information questionnaire, the 10-item Center for Epidemiologic Studies Depression Scale, the Pittsburgh Sleep Quality Index Scale, the Social Avoidance and Distress Scale, and the Fear of Missing Out Scale. Analyses were performed with SPSS 25.0 and R Studio 4.4.1. Group comparisons were conducted using the Wilcoxon rank-sum or Kruskal-Wallis H tests. Spearman correlation analyses examined associations among variables. Mediation analysis was performed with the PROCESS 4.0 program. The significance of indirect effects was tested by bootstrapping and structural equation modelling. Results A total of 614 clinical nurses were ultimately enrolled, of whom 36 (5.9%) were male and 578 (94.1%) were female. The mean depression score was 9.38 ± 5.42, corresponding to a positive screening rate of 50.81%. Mediation analyses showed that night shift workload positively predicted depressive symptoms ( β = 0.0416, 95% CI : 0.0351–0.0481). Sleep disturbance, SAD, and FOMO each emerged as significant partial mediators. The indirect effects were 0.0381 (95% CI : 0.0307–0.0459), 0.0120 (95% CI : 0.0078–0.0168), and 0.0122 (95% CI : 0.0080–0.0170), accounting for 29, 9.13, and 9.28% of the total effect, respectively. The structural equation model indicated a good fit for the proposed mediation framework. Conclusion Night shift workload positively predicts depressive symptoms among nurses, and sleep disturbance, SAD, and FOMO partially mediate this relationship. Comprehensive, multi-target interventions should therefore be implemented to lower depression risk and safeguard the mental health of nurses working night shifts.