Mental Health
Sleep Quality and Psychological Resilience Across Borders: Evidence from the WELL US and China Cohorts Eunhye Lee* Eunhye Lee Lee Lee Lee Lee Lee Lee Lee Lee Lee Lee Lee Lee Lee Stanford Prevention Research Center, Department of Medicine, Stanford University School of Medicine, Stanford, California, USA
Objective: Sleep is increasingly recognized as a modifiable determinant of psychological resilience, yet cross-cultural evidence remains limited. We examined whether the association between sleep quality and psychological resilience is consistent across the United States (US) and China.
Methods: We analyzed cross-sectional baseline data from the WELL cohorts in the US and China. Sleep quality was assessed using the Pittsburgh Sleep Quality Index (PSQI) among US (n=467) and Chinese (n=9,780) participants, with poor sleep defined as a score >5. We also examined the full US cohort (n=6,457) using a single-item sleep measure. Psychological resilience was measured using a 9-item scale adapted from the Brief and Connor-Davidson Resilience Scales (low resilience: below-median score). Multivariable logistic regressions estimated ORs and 95% CIs for the association between sleep quality and psychological resilience, adjusting for demographic and socioeconomic factors and mental health indicators including loneliness and history of depression.
Results: Poor sleep quality was significantly associated with increased odds of low psychological resilience in both countries, with findings replicated across two sleep measures in the US. The association did not differ by gender, age, or history of depression in either country (interaction P>0.05). Loneliness modified the association in China only (interaction P<0.05), with a larger magnitude of association among lonely participants (OR=2.1; 95% CI:1.6-2.7) than among non-lonely participants (OR=1.5; 95% CI:1.4-1.7).
Conclusions: Poor sleep quality was consistently associated with lower psychological resilience across both US and China cohorts. These findings provide cross-cultural evidence supporting sleep quality as a modifiable target for resilience-building interventions. The moderating role of loneliness suggests that promoting wider and more meaningful social connections may strengthen sleep interventions in China.