mental health Strengths and limitations of this study By sampling adults from each of China’s provinces, this is the first study that is able to assess how the prevalence of depression during the COVID-19 pandemic varied across provinces. We explored how the prevalence of depression varied within provinces by individuals’ socioeconomic characteristics, and are thus able to inform which population groups might be suitable target groups for prevention and treatment of depression during the pandemic. Our sample is unlikely to be representative of the general population of China because participants had to be registered with an online survey company (KuRunData)...