Mental Health and Kidneys: The Interplay Between Cognitive Decline, Depression, and Kidney Dysfunction in Hospitalized Older Adults

Background: As societies rapidly age, the prevalence of mental health disorders and chronic kidney disease (CKD) is simultaneously rising, and data on the link between these conditions remain inconclusive. This study aimed to investigate the associations among cognitive impairment, depression, and kidney involvement in elderly patients. Methods: A cross-sectional analysis was conducted among hospitalized patients aged ≥65 years. Standardized tools such as the geriatric depression scale (GDS) and Montreal Cognitive Assessment (MoCA) were used to assess depression and cognitive impairment, and kidney function was evaluated using eGFR and albuminuria. Bivariate and multivariate logistic regressions were performed to identify associations. Results: The study population consisted of 719 participants with a median age of 80 years. Kidney and mental health issues were highly prevalent: CKD was identified in 59.4%, cognitive impairment in 74%, and depression in 61.9% of patients. Patients with CKD were older and exhibited lower MoCA scores (p = 0.001), higher GDS scores (p = 0.007), reduced albumin (p < 0.001), lower hemoglobin levels (p < 0.001), and elevated C-reactive protein (p < 0.001). Increased albuminuria was associated with poorer cognition (p < 0.001) but showed no correlation with GDS scores. Additionally, worse cognitive scores (p = 0.001) and increased depression symptoms (p < 0.001) were correlated with declining estimated glomerular filtration rate (eGFR). Conclusions: Cognitive impairment and depressive symptoms are highly prevalent among elderly hospitalized patients. Cognitive decline correlates with increased albuminuria and reduced eGFR, while depression worsens with declining kidney function. These findings highlight the complex interplay between renal health and neuropsychiatric conditions in aging populations.