Association between uric acid and the risk of depressive symptoms in US adults: results from NHANES 2005–2018

Abstract Background This study explores the relationship between serum uric acid(UA) levels and depression. UA is the final product of purine metabolism in the human body, possessing certain physiological functions such as blood pressure regulation, antioxidation, DNA protection, and anti-aging, thereby drawing attention for its potential role in preventing and treating depression. Methods This cross-sectional study includes 32,424 participants aged ≥ 20 years from the National Health and Nutrition Examination Survey (NHANES) conducted between 2005 and 2018, generating a nationally representative database. Depressive symptoms were assessed using the Patient Health Questionnaire-9. Serum uric acid concentration was measured using the uricase-peroxidase coupled method, and participants were divided into quartiles of serum uric acid concentration. Weighted data were calculated according to analysis guidelines. The association between serum uric acid and depressive symptoms was analyzed using weighted multivariable logistic regression models and restricted cubic spline regression analyses. Subgroup analyses were also performed. Results Among 32,424 participants, 3,421 were defined as having depressive symptoms. The crude prevalence of depressive symptoms was 10.5% (weighted prevalence: 9.086% [95% confidence interval: 9.032–9.139%]). Compared with the first quartile, individuals with higher UA levels had a decreased risk of depressive symptoms by 9% (OR: 0.910, 95% CI: 0.797–10.40), 14.6% (OR: 0.854, 95% CI: 0.741–0.983), and 20.5% (OR: 7795, 95% CI: 0.680–0.930), respectively. Further restricted cubic spline regression analysis revealed a nonlinear association between UA and depressive symptoms, with an inflection point of 319.72 µmol/L. Subgroup multivariable weighted logistic regression analysis found that the association between UA and the risk of depressive symptoms remained consistent across all subgroups, demonstrating high stability and reliability. Conclusion This study emphasizes a significant nonlinear negative correlation between serum uric acid and depressive symptoms. This suggests that proper control of serum uric acid levels may play a role in preventing and treating depression.