GOLD BioAge and depression: Associations with mortality among depressed NHANES participants (2005-2018)

BACKGROUND: Biological ageing, measured by Gompertz Law-Based Biological Age (GOLD BioAge), may be associated with depression risk in U.S. adults and with mortality among individuals with depression, but these relationships remain incompletely characterized. METHODS: We conducted a cross-sectional analysis of NHANES 2005-2018 data to evaluate the association between GOLD BioAge and depression in U.S. adults, and performed a retrospective cohort analysis to examine its relationship with all-cause mortality among individuals with depression, using logistic regression, Cox proportional hazards models, and Kaplan-Meier survival curves. RESULTS: Among 30,885 participants (mean age 49.9 ± 17.7 years; 49.9% female), Restricted cubic spline (RCS) regression revealed a significant nonlinear association (p for non-linear <0.001) between GOLD BioAge and depression. Compared with the third quartile of GOLD BioAge (Q3), depression risk was 45% lower in Q4 (OR = 0.55, 0.49-0.63, p < 0.001), whereas no significant difference was observed in Q1 (p = 0.85) and Q2 (p = 0.477). In 2658 depressed participants, higher GOLD BioAge was associated with increased all-cause mortality. In the fully adjusted model, each one-year increase in GOLD BioAge corresponded to a 7% higher risk of death (HR = 1.07, 95% CI 1.06-1.08, p < 0.001). RCS indicated a linear dose-response association, and Kaplan-Meier curves showed progressively lower survival with increasing BioAge tertiles. CONCLUSION: GOLD BioAge captures multi-system physiological burden, showing a nonlinear association with depression and a linear association with mortality among individuals with depression, supporting its potential utility for risk stratification.