Risk of depression in patients with chronic respiratory diseases: results from two large cohort studies in Chinese elderly from Hong Kong

OBJECTIVE: Although it has been suggested that depression is common in patients with chronic respiratory diseases such as chronic obstructive pulmonary disease (COPD), few studies on the association between chronic respiratory diseases and depression have been conducted in the community. METHOD: Data from the baseline examination of two cohort studies, Mr and Ms Os, Hong Kong were used. Three thousand nine hundred and ninety-eight Hong Kong men and women aged 65 to 92 were recruited. Depression was assessed by face-to-face interview, using the short-form of a validated Chinese version of the Geriatric Depression Scale (GDS). Chronic respiratory disease was assessed by subjects' self reports of chronic respiratory disease (chronic bronchitis, emphysema and asthma) diagnosed by medical doctors. Adjusted odds ratios (ORs) and corresponding 95% confidence intervals (CI) for depression among subjects with chronic respiratory diseases relative to those without (controls) were calculated, after adjustments were made for potential confounders. RESULTS: Chronic respiratory disease was associated with a higher prevalence of depressive disorders with an odds ratio of 1.58 (95% CI = 1.12-2.13) after adjustment was made for age, sex, cigarette smoking, alcohol drinking and history of cardiovascular diseases when compared with controls. For those subjects with self report of chronic respiratory disease and who screened positive for depression (n = 44), none were on antidepressants. Among subjects who screened positive for depression without self-report of chronic respiratory disease (n = 328), only 2.74% (n = 9) were on antidepressants. CONCLUSIONS: We conclude that chronic respiratory disease is independently associated with depression in Chinese elderly. Moreover, depression in the elderly is under-treated in those with and without chronic respiratory disease. Clinicians, especially primary care physicians in the community, should be more aware of increased prevalence of depression in patients with chronic respiratory disease.