Chronic Respiratory Disease and Mental Health: the Guangzhou Biobank Cohort Study

Respiratory diseases have been linked to poor mental health in Western populations. Since the experience and expression of mental ill-health is partly culturally determined, it is of interest to examine if similar associations are found in other cultural settings. In that regard, very little is known about the association between respiratory disease and mental health in Asian countries, such as China, which we investigated in the current study. Methods: We used data from phase 3 recruitment of the Guangzhou Biobank Cohort Study (n=10,888). Respiratory diseases included asthma (physician-diagnosed self-reports) and chronic obstructive pulmonary disease (COPD), which was assessed by spirometry (FEV1:FVC < the lower limit of normal) and by self-reported respiratory symptoms (chronic cough, phlegm, and dyspnea). Mental health measures included the 15-item Geriatric Depression Scale (GDS) and the SF-12 mental component summary (MCS) score. Depression was defined as a GDS score of 6 or higher, while poor mental health was defined as score more than 1 SD below the mean MCS score. Logistic regression was used to estimate multivariable odds ratios (ORs) and 95% confidence intervals (CIs). Results: Asthma was associated with both depression (OR=2.75, 95% CI=1.78–4.26) and poor mental health (OR=1.64,95% CI=1.06–2.53). Among asymptomatic individuals, those with normal lung function did not significantly differ from those with evidence of airway obstruction in relation to depression (OR=0.53, 95%=0.27–1.05) or poor mental health (OR=0.92, 95% CI=0.59–1.45). However, those with respiratory symptoms were more likely to have depression or poor mental health regardless of whether their lung function was poor (OR depression=1.62, 95%=1.02–2.55; OR poor mental health=1.86, 95%=1.26–2.73) or normal (OR=2.29, 95% CI=1.95–2.69; and OR=2.16, 95% CI=1.89–2.47, respectively). Conclusions: We found asthma to be associated with both depression and poor mental health in a large sample of adults from China. With regard to COPD, only self-reported respiratory symptoms, but not objective lung function, was related to depression.