Variety, Frequency, and Type of Internet Use and Its Association with Risk of Depression in Middle- and Older-aged Chinese: A Cross-sectional Study

Background: Internet use is beneficial to mental health has been acknowledged, but its specific patterns await further investigation in China's context of urban-rural disparity. Therefore, we aimed to understand the patterns of Internet use and measure their associations with risk of depression in China from three dimensions: variety, frequency and type.

Methods: We selected 18,492 urban and rural Chinses respondents aged 45 years and older from China Health and Retirement Longitudinal Study (CHARLS) 2015 dataset. Risk of depression was measured by 10-item Centre for Epidemiologic Studies (CES-D 10). Internet use was measured from three dimensions: variety, frequency and type, whereas its relationship with risk of depression was examined by multivariate logistic regression model.

Results: In the whole sample, 67.2% of respondents had no risk of depression, and approximately 7% used Internet, which was inversely associated with risk of depression (AOR=0.617, 95% CI=0.444, 0.858). Rural respondents had higher risk of depression (37.1% VS 26.2%) and lower prevalence of Internet use (2.6% VS 13%). Among rural respondents, using Internet occasionally (AOR=0.338; 95% CI=0.130, 0.881), using one type of device (AOR=0.293; 95% CI=0.113, 0.760), especially mobile phone (AOR=0.427; 95% CI=0.187, 0.978) were associated with lower odds of depression. No significant associations were observed in urban respondents.

Limitations: The causal relationship between variables awaits further investigation with a longitudinal design.

Conclusion: Internet use was negatively associated with risks of depression, especially in rural but not in urban participants. Rural-urban disparities should be considered when designing strategies to encourage moderate Internet use.