AUTHOR=Bao Jing , Li Peile , Guo Yang , Zheng Yanxu , Smolinski Michael , He Jinshen 

TITLE=Caffeine is negatively associated with depression in patients aged 20 and older

JOURNAL=Frontiers in Psychiatry

VOLUME=Volume 13 - 2022

YEAR=2022

URL=https://www.frontiersin.org/journals/psychiatry/articles/10.3389/fpsyt.2022.1037579

DOI=10.3389/fpsyt.2022.1037579

ISSN=1664-0640

ABSTRACT=Previous studies have observed the association between caffeine intake and depression, but few have considered the potential threshold effect of this issue. Therefore, the study aimed to examine the association between caffeine consumption and depression in patients aged 20 years or older using curve fitting analysis. The population was 3263 patients from the 2017-2018 National Health and Nutrition Examination Survey (NHANES) with reliable answers to questions of caffeine intake and depression. Participants’ depression levels were assessed using the PHQ-9 depression scale and the caffeine consumption were investigated in a private room of NHANES. The confounding variables of this study included level of education, monthly sleepiness, age, marital status, race, cigarette smoking, sex and recreational activities. In linear regression analysis, patients with a higher PHQ-9 score tend to have less caffeine intake. A similar conclusion was drawn in logistic regression model using PHQ-9 ≥ 10 as a cut-off score for depression. But when caffeine intake exceeded 90 mg, there was no significant association between caffeine intake and depression based on the curve fitting analysis. These results suggest that people can consume some caffeine to reduce depression. But further study is needed to examine the precise causal relationship between these factors.