Associations between education levels and prevalence of depressive symptoms: NHANES (2005-2018)

Purpose: Our study investigated the relationships between the prevalence of depressive symptoms and education levels in those aged >= 20 years. Methods: A total of 34,102 participants from the National Health and Nutrition Examination Surveys 2005-2018 were involved in our cross-sectional study. The relations of depressive symptoms (as outcome variable) and education levels (as an independent variable) were analyzed using multivariable logistic regression models in the main analyzes. Sensitivity analyzes, including a multiple sensitivity analysis, were also performed. Result: The education levels were negatively associated with depressive symptoms after adjusting related covariates. Compared with the reference group of individuals with less than 9th grade, people with college graduate or above had an adjusted odds ratio (OR) of 0.464 (95% CI 0.361, 0.595, P < 0.0001). On the other hand, the statistically significant negative association disappeared among Mexican Americans, other races, separated, and high family poverty income ratio group. These results remained stable under a wide range of sensitivity analyzes. Conclusion: Our study indicated the elevated education levels correlated with the decreased prevalence of depressive symptoms, and race, marital status, and family economic factors played a critical role in the relationship. This report reminds us to pay close attention to the further study of factors that affected the association between depressive symptoms and education levels. Limitations: The cross-sectional study leaves problems about the direction of causality unclear.