Supplementary Material for: Association between depressive symptoms and mild cognitive impairment among the elderly in China: a community-based study

Background: Elderly individuals with depressive symptoms often show increased susceptibility to mild cognitive impairment (MCI). This study explores the association between depressive symptoms and MCI among older adults in China. Methods: Data from the Shanghai Brain Aging Study (SBAS) were used in this cross-sectional study. MCI was diagnosed through clinical assessments and Montreal Cognitive Assessment (MoCA) scores (≤23). Depressive symptoms were defined as a Geriatric Depression Scale (GDS) score >10. Binary logistic regression and restricted cubic spline (RCS) analyses were conducted to evaluate the associations between depressive symptoms and MCI, adjusting for potential covariates. Results: The study included 1506 participants, with 43.6% diagnosed with MCI. Logistic regression analysis revealed a significant association between depressive symptoms and MCI. In the fully adjusted model, depressive symptoms were associated with a 65% higher likelihood of MCI (odds ratio: 1.65, 95% confidence interval: 1.17–2.34). RCS analysis indicated a significant non-linear relationship between depressive symptoms and MCI (P for non-linear = 0.029). Participants with depressive symptoms scored significantly lower on the MoCA subscores for visuospatial and executive function, as well as language abilities (all P < 0.05). Conclusions: Our findings demonstrate a significant association between depressive symptoms and MCI, with depressive symptoms being linked to a higher prevalence of MCI. Early identification and intervention of depressive symptoms, including community screening, psychological therapies, or pharmacological treatments for older adults, may potentially mitigate cognitive decline. However, the cross-sectional design limits causal conclusions, and generalizability may be affected by self-reported depression measures and regional sampling.