Does internet use promote mental health among middle-aged and older adults in China?

In recent years, China's Internet penetration rate has increased, and the scale of middle-aged and older adults' netizen has continued to expand. However, the impact of internet use on mental health remains controversial. This paper analyzes 14,497 middle-aged and older adults' valid respondents in the 2018 Chinese Family Panel Study (CFPS2018) to evaluate the impact of Internet use on the mental health of middle-aged and older adults and its intermediary mechanisms. The findings show that moderate use of the Internet can significantly reduce depression levels and boost cognitive function in middle-aged and older adults. But excessive internet use will also lead to increased levels of depression and decreased cognitive function. Different Internet use purposes will also lead to different psychological states. Online socializing, entertainment and business activities can significantly reduce depression levels and promote cognitive functions. Online studying and working only have positive effects on cognitive functions, which have no significant relationship to depression levels. In addition, analysis of the mediation effect found that life satisfaction is a path mechanism for Internet use and affect different dimensions of mental health.