Depressive symptoms in younger adults before and during the COVID-19 pandemic: A nationally representative cross-sectional data analysis.

OBJECTIVE: Several studies have reported an increased prevalence of depressive symptoms during the coronavirus disease 2019 (COVID-19) pandemic. However, the prevalence of significant depressive symptoms and its associated factors in younger adults remain uncertain. We aimed to investigate this association during the COVID-19 pandemic and make a comparison with the pre-pandemic period. METHODS: Cross-sectional data from the 2018 and 2020 Korea National Health and Nutrition Examination Surveys were analyzed, and 3281 respondents aged 19-40 years were included. We defined a Patient Health Questionnaire-9 score ≥ 10 as significant depressive symptoms and the categories of depressive symptoms were also classified as none, mild, moderate, and severe. RESULTS: The prevalence of significant depressive symptoms was higher in the pandemic group (7.4% vs. 4.7%). Furthermore, the prevalence in the pandemic group was higher for all degrees: mild, moderate, and severe depressive symptoms. A multivariable logistic regression indicated that significant depressive symptoms during the pandemic was significantly associated with female sex, low educational attainment, unemployment, chronic medical disease, and being overweight. CONCLUSIONS: Our findings suggest an increase in depressive symptoms in younger adults during the pandemic. It is necessary to develop policies to provide younger adults with resources to cope with depressive symptoms related to COVID-19 and potential global outbreak of infectious disease.

Association between uric acid and depressive symptoms in older adults: The Korea National Health and Nutrition Examination Survey.

BACKGROUND: Uric acid is known for its antioxidant capacity; however, whether uric acid is independently associated with depression in the older population remains controversial. The current study aimed to investigate the association between uric acid and depressive symptoms in older adults according to sex, using a large national sample population. METHODS: Data from the 2016, 2018, and 2020 Korean National Health and Nutrition Examination Surveys were analyzed, and 5609 participants older than 60 years were included in this study. We defined a Patient Health Questionnaire-9 score ≥5 as indicating the presence of depressive symptoms. RESULTS: The prevalence of depressive symptoms was higher in women with lower uric acid levels than in those with higher uric acid levels. In women, the lower levels of uric acid were significantly associated with depressive symptoms in the multivariable logistic regression analysis (odds ratio, 1.36; 95% confidence interval, 1.10-1.68; p = 0.005). However, no significant association between uric acid levels and depressive symptoms was observed in men. CONCLUSION: The findings of this study suggest that uric acid is associated with depressive symptoms in older women, but not in men. Relatively lower serum uric acid levels in women compared to men and sex differences in oxidative stress may explain the significant association of uric acid levels and depressive symptoms in older women. Further research is needed on sex differences in the relationship between serum uric acid levels and depressive symptoms.

Association between anemia and depression: The 2014, 2016, and 2018 Korea National Health and Nutrition Examination Survey.

BACKGROUND: Several studies have reported an association between anemia and depression. However, whether anemia is independently associated with depression remains controversial. The current study aimed to investigate the association between anemia and depression according to sex in a large national sample population. METHODS: Data from the 2014, 2016, and 2018 Korean National Health and Nutrition Examination Survey were analyzed, and 15,472 participants were included in this study. Anemia was defined as a hemoglobin level <13 g/dL in men and <12 g/dL in women. We defined a Patient Health Questionnaire-9 score ≥10 as depression and ≥5 as mild depressive symptoms. RESULTS: The prevalence of depression was significantly higher in women with anemia than in women without anemia (8.9 % vs. 7.0 %, P = 0.036). In women, anemia was significantly associated with depression after adjusting all covariates in multilevel logistic regression analysis (odds ratio, 1.37; 95 % confidence interval, 1.08-1.75; P = 0.011). However, no significant association was observed in men. LIMITATIONS: There is a limit to explaining the causal direction, and several factors may not have been considered as confounders. Also, patients with severe diseases were excluded from data acquisition. A structured diagnostic interview, other than the self-report method, was not conducted. CONCLUSIONS: The findings of this study suggest that anemia is associated with depression in women but not in men. A decrease in tissue oxygenation, deterioration of physical performance due to anemia, and altered monoamine synthesis due to malnutrition may have an effect on depression.