Relationship between depression and exacerbations in COPD.

Chronic obstructive pulmonary disease is associated with exacerbations. Some patients are prone to frequent exacerbations and these individuals have a worse quality of life, greater limitation of their daily activity and faster disease progression than patients with less frequent exacerbations. A prospective study in a well-characterised cohort was performed and it was assessed whether depression, as determined by the Centre for Epidemiologic Studies Depression Scale, was related to exacerbation frequency, systemic inflammation and various social factors. The associations of any increase in depressive symptoms at exacerbation were also investigated. Frequent exacerbators had a significantly higher median (interquartile range) baseline depression score than infrequent exacerbators (17.0 (7.0-25.0) and 12.0 (6.0-18.0), respectively). Depressed patients spend significantly less time outdoors and had significantly worse quality of life as measured by the St George's Respiratory Questionnaire. Depression increased significantly in patients from baseline to exacerbation (12.5 (5.0-19.0) and 19.5 (12.0-28.0) respectively). The present study is the first to show a relationship between depression and exacerbation frequency in patients with chronic obstructive pulmonary disease. The finding that frequent exacerbators are more depressed than infrequent exacerbators is relevant, as exacerbation frequency is an important outcome measure in chronic obstructive pulmonary disease.