The Coronavirus Disease 2019(COVID-19)epidemic emerged in Wuhan,China,spread nationwide and then onto half a dozen other countries between December 2019 and early 2020.The implementation of unprecedented strict quarantine measures in China has kept a large number of people in isolation and affected many aspects of people's lives.It has also triggered a wide variety of psychological problems,such as panic disorder,anxiety and depression.This study is the first nationwide large-scale survey of psychological distress in the general population of China during the COVID-19 epidemic.