Association between stock market volatility and severe mental disorders: a multi-city time-series study

Background: Stock market volatility was commonly considered as a psychological stressor. However, the association between stock market volatility and severe mental disorders (SMD) has not been investigated. Methods: Daily numbers of SMD hospital admissions and Shanghai Stock Exchange Composite (SSEC) Index in 7 cities in southwestern China from 2020 to 2023 were collected. A two-stage time-series analysis was conducted to reveal the association between stock volatility and the risk of hospital admission for SMD. Stratified analyses were performed by age, gender, and ICD-10 codes to explore potential high-risk groups. Results: The association between the SSEC percentage change, SSEC closing price and SMD hospital admissions both exhibit a U-shaped curve. A 1 % decrease in SSEC is associated with a 7.2 % (95 %CI: 4.1 %-10.4 %) increase in the SMD admission, while a 1 % increase in SSEC is associated with a 2.6 % (95 %CI: 0.1 %-5.2 %) increase in the SMD admissions. With 3400 points as the dividing point, every 10-point increase in SSEC closing price is associated with a 9 % (95 %CI: 3.6 %-14.7 %) increase in the SMD hospital admissions, while each 10-point decrease is associated with a 4.4 % (95 %CI: 0.6 %-8.3 %) increase in the SMD hospital admissions. Furthermore, these associations tended to be stronger in the female and non-schizophrenia patients. Conclusion: These associations indicate that both rise and fall in stock prices increase the risk of SMD. This finding suggests that it is an effective way to take the stock speculation behavior into consideration when managing and treating the SMD patients.