For a study, researchers investigated the incidence of comorbid depression and anxiety in patients with COPD and their response to eight weeks of pulmonary rehabilitation (PR). Seven hundred thirty-four participants with clinically stable COPD underwent an eight-week outpatient multidisciplinary PR consisting of two hours per week (1 hour of exercise and one hour of education). The incremental shuttle walk test (ISWT), St. George’s Respiratory Questionnaire (SGRQ), and modified Medical Research Council (mMRC) scales were used to assess depression and anxiety, exercise ability, quality of life (QOL), and dyspnea before and after PR. After completing the Depression Anxiety Stress Scale (DASS-21), individuals were categorized as having clinically significant comorbid anxiety and depression, anxiety alone, depression alone, or neither. 

Patients were 71 (8.8) years old on average (SD), with 51% of them being men. Pre-PR, 34% of people had comorbid depression and anxiety, 20% had anxiety alone, 5% had depression alone, and 41% had neither. Stress was found to be prevalent in 59% of the population. Total SGRQ score improved from 64.9 (13.8) pre-PR to 50.1 (17.2) post-PR (P<0.001), mMRC score improved from 3.4 (1.0) pre-PR to 2.8 (1.1) post-PR (P<0.001), and ISWT distance walked rose from 188.6 (117.6) pre-PR to 248.6 (149.1) post-PR (P<0.001). One in every three COPD patients has comorbid depression and anxiety, which was reflected in symptoms of increased dyspnea and poor quality of life.