Climate change and depressive disorders in middle-aged and older people in China: A quasi-experimental study

Global climate change has been increasingly recognized as one of the most significant threats to global health, including mental health. Although many studies have explored the link between mental health problems and climate change, the findings are inconclusive, especially regarding the effect on depressive disorders. A possible limitation is the lack of comprehensive assessment of climate change. This study aimed to comprehensively investigate the effects of temperature-related consequences of climate change (including changes in average temperature, temperature variability, heat waves, cold spells, and hot nights) on depressive disorders among middle-aged and older people who are more vulnerable to climate change because of their reduced thermoregulation capacity with aging. Our findings suggest that both hot nights and cold spells significantly exacerbate depressive disorders (hot nights: Excess Risk (ER) = 9.60% (95%CI: 1.59%, 18.24%); cold spells: ER = 3.63% (95%CI: 0.77%, 6.57%)). However, we did not find sufficient evidence to support the effect of average temperature, temperature variability, and heat waves on depressive disorders among middle-aged and older people in China. To conclude, depressive disorders was sensitive to extreme hot at night and cold. The government should propose some measures to mitigate the impact of extreme temperature events, such as launching campaigns to promote air conditioning in rural areas where the penetration rate of air conditioning is low.