Depression and chronic medical illnesses in Asian older adults: the role of subjective health and functional status.

OBJECTIVE Depression in elderly is reportedly associated with a number of specific chronic illnesses. Whether each of these co-morbid associations results uniquely from disease-specific psychobiological responses or is mediated by non-specific factors like subjective health and functional status is unclear. METHOD Analysis of data of 2,611 community-dwelling Chinese aged 55 and older, including depressive symptoms defined by Geriatric Depression Scale score >or= 5 and self-reports of specific chronic illnesses. RESULTS The prevalence of depressive symptoms was 13.3%, lower in those without chronic illness (7.5%), and higher in those with illnesses (13.2-24.2%). Crude Odds Ratios (OR) were significantly elevated for hypertension, eye disorders, diabetes, arthritis, ischemic heart disease, asthma/COPD, stroke, osteoporosis, heart failure, thyroid problem, and gastric problem. In multivariable analyses, only asthma/COPD [OR:2.85, 95% Confidence Intervals (CI): 1.36, 5.98], gastric problem (OR:2.64, 95% CI: 1.11, 6.29), arthritis (OR:1.87, 95% CI: 1.02, 3.42) and heart failure (OR:2.11, 95% CI: 0.98, 4.58) remained independently associated with depressive symptoms, after adjusting for comorbidities, subjective health and functional status, cognitive functioning, smoking, alcohol, psychosocial and demographic variables. CONCLUSION Most comorbid associations of depressive symptoms with specific chronic illnesses are explained by accompanying poor self-reported health and functional status, but some illnesses probably have a direct psychobiological basis.