Psychological resilience, insomnia, and anxiety among Chinese medical students: a moderated mediation model with academic stress

Anxiety is highly prevalent among medical students and poses significant threats to their academic performance and mental health. Psychological resilience has been identified as a protective factor against anxiety. This study examined whether insomnia mediated the association between resilience and anxiety, and whether academic stress moderated this mediation pathway. A cross-sectional survey was conducted among 4,219 medical students from two medical universities in Heilongjiang Province, China. Anxiety symptoms, insomnia severity, psychological resilience, and academic stress were assessed using the DASS-21, Insomnia Severity Index (ISI), Connor-Davidson Resilience Scale-10 (CD-RISC-10). Of the 4,219 participants, 24.3% screened positive for anxiety symptoms. Resilience was negatively associated with both insomnia (B=-0.119, P < 0.001) and anxiety (B=-0.111, P < 0.001), while insomnia was positively associated with anxiety (B = 0.834, P < 0.001). Insomnia significantly mediated the association between resilience and anxiety (indirect effect=-0.099, 95% CI: -0.114, -0.084), accounting for 47.24% of the total effect. Furthermore, academic stress significantly moderated the insomnia-to-anxiety pathway (B = 0.094, P < 0.001); the indirect effect of resilience on anxiety via insomnia was stronger among students with severe academic stress (effect=-0.118, 95% CI: -0.134, -0.103) than among those with mild academic stress (effect=-0.104, 95% CI: -0.124, -0.086). The index of moderated mediation was − 0.013 (95% CI: -0.025, -0.001). Insomnia partially mediated the association between psychological resilience and anxiety among medical students, and this mediation was moderated by academic stress. These findings suggested that interventions targeting both sleep quality and academic stress management may be effective in reducing anxiety among medical students with lower resilience.