The negative impact of loneliness and perceived stress on mental health during two-month lockdown in Shanghai

Background: Shanghai undergone COVID-19 lockdown for 2 months in 2022, affecting >25 million population. We aim to find changes in mental health during Shanghai lockdown and if mental health was associated with Shanghai lockdown, loneliness, and perceived stress.Methods: We conducted two cross-sectional online surveys in China, which were before and at the end of Shanghai lockdown (survey 1 in January 2022, N = 1123; survey 2 in June 2022, N = 2139). Participants re-ported mental health, loneliness, and perceived stress through the 12-item General Health Questionnaire (GHQ -12), the short-form UCLA Loneliness Scale (ULS-8), and the 10-item Perceived Stress Scale (PSS-10). We compared data between survey 1 and 2. We ran a multiple linear regression model to investigate the impact of Shanghai lockdown, loneliness and perceived stress on mental health.Results: There's an increase in the proportion of lonely people during Shanghai lockdown (49.77 % to 65.26 %). During Shanghai lockdown, the proportion of lonely people (68.97 % VS. 61.35 %, p < 0.001) and risk for mental health conditions (50.50 % VS. 43.27 %, p < 0.001) were higher among residents in Shanghai than outside Shanghai. Shanghai lockdown (b = 0.556, p = 0.02), higher ULS-8 (b = 0.284, p < 0.001) and higher PSS-10 (b = 0.365, p < 0.001) were associated with higher GHQ-12. Limitations: Participants reported their mental health status during Shanghai lockdown retrospectively.Conclusion: Shanghai lockdown had psychological impacts not only on residents in Shanghai but also outside Shanghai. Addressing loneliness and perceived stress accommodated to the lockdown situation should be considered.