The Cognitive and Mood-Related Costs of Loneliness: Why Marital Status Matters in Old Age.

Background: The 21st century is characterized by a significant and ongoing rise in the aging population across Europe. In this context, marital status may act as a relevant social factor influencing health trajectories in later life. This study explores the association between marital status and various health-related outcomes in community-dwelling older adults. Methods: We enrolled 1201 patients ≥ 65 years (median age: 81, interquartile range (IQR): 76-84) attending the Geriatric Outpatient Service at the University Hospital of Cagliari. Each participant underwent a Comprehensive Geriatric Assessment (CGA). Results: Married individuals were significantly less likely to report depressive symptoms (Risk Ratio (RR) = 0.82; 95% Confidence Interval (CI): 0.73 to 0.92; p = 0.0004) and had a 1.26-point reduction in Geriatric Depression Scale (GDS) scores (β = -1.26; 95% CI: -2.03 to -0.50; p = 0.0013). Separate/Single participants exhibited significantly higher Mini-Mental State Examination (MMSE) scores (β = 1.60; 95% CI: 0.19 to 3.01; p = 0.0262). In contrast, Widowed individuals showed significantly poorer cognitive performance (RR = 1.12; 95% CI: 1.02 to 1.23; p = 0.0204), with lower MMSE scores (β = -1.10; 95% CI: -2.08 to 0.12; p = 0.0279). They also had a higher likelihood of depressive symptoms (RR = 1.16; 95% CI: 1.04 to 1.30; p = 0.0072) and a 1.19-point increase in GDS scores (β = 1.19; 95% CI: 0.38 to 1.99; p = 0.0039). Conclusions: Although observational design precludes causal inference, our findings highlight the significance of marital status as a social factor associated with cognitive function and mood in older adults. Integrating this dimension into the CGA may enhance its ability to capture social vulnerabilities in later life.