The Overlooked Burden: Chronic Obstructive Pulmonary Disease and Mental Illnesses

Chronic obstructive pulmonary disease (COPD) represents an important public health challenge that is both preventable and treatable. It is a major cause of chronic morbidity and mortality throughout the world. During the past two decades, there has been increasing recognition that patients with COPD with three or more comorbidities are more likely to be frequently hospitalized and may die prematurely compared with COPD patients without comorbidities.[1] Most patients with COPD suffer from severe exercise intolerance. Sometimes, they face extreme limitations in their day-to-day activities. This leads to dependence on others for their routine activities. This may lead to disturbed mental status, and unless they get support from family members and friends, the quality of life deteriorates, leading to anxiety or depression. While the physical symptoms of COPD, such as dyspnea, chronic cough, and fatigue, are well-documented, the psychological burden of the disease often remains underrecognized. Depression and anxiety are among the key comorbidities of COPD, adding to the disease burden by diminishing quality of life and hindering treatment adherence.[2] Depression and anxiety in COPD patients are associated with increased hospitalizations, decreased physical activity, and a higher mortality risk.[3] Understanding the interplay between COPD and mental health disorders is crucial for improving patient outcomes. The Indian studies published so far have revealed a high prevalence of depression (50%–72%) among stable COPD patients based on self-administered questionnaires.[4] Anxiety and depression often appear together in patients with COPD.[5] While the exact causes of these symptoms have not been well defined, several variables have been implicated, including physical disability, long-term oxygen therapy, severe dyspnea, poor quality of life, presence of comorbidities, current smoking, and low socioeconomic status. The impact of anxiety and depression on COPD patients, their families, and society is significant. Depression has been found to predict fatigue, shortness of breath, and disability in patients with heart disease or COPD, even after adjusting for the severity of illness.[6,7] In addition, depression decreases treatment adherence. COPD has a significant negative impact on patients’ mental health. Compared to the general population. People with COPD have greater rates of depression and anxiety. When compared to other chronic comorbid conditions, COPD patients may even have higher rates of both anxiety and depression. These may range from short-term subclinical depressive symptoms to dysthymia (long-term chronic symptoms that are not disabling) to clinical depression.[8] It has been noted that patients with COPD and depression experience more dyspnea than their counterparts without depression. This was demonstrated by a study of 836 patients in whom greater dyspnea was noted in depressed versus nondepressed COPD patients (Medical Research Council [MRC] dyspnea scale, 2.07 vs. 1.32; P < 0.0001).[9] Tobacco smoke is considered an important environmental risk factor for the development of COPD, and high levels of anxiety are, in turn, a risk factor for smoking initiation.[10,11] Patients with COPD secondary to smoking tobacco are likely to have higher levels of anxiety. The presence of depression and anxiety in patients with COPD leads to “vital exhaustion” (fatigue and lack of energy, and feelings of demoralization), which leads to poor health status.[12] Biswas et al.[13] have reported that the majority of stable COPD patients suffer from anxiety and depression (32 out of 75), while 9 each had either anxiety or depression. Scheider et al.[14] studied 35,000 patients with COPD and followed them up for 10 years. The incidence of depression in this longitudinal study was 16.2 cases per 1000 person-years in the COPD group compared with 9.4 cases per 1000 person-years in the non-COPD control group. A statistically significant positive association was reported between the smoking index and anxiety scores, although the correlation with depression scores was not significant. This conclusion aligns with the study of Floyd et al. in 2021, who determined that COPD patients exhibiting increased nicotine dependence experienced heightened psychological suffering.[15] The more pronounced correlation with anxiety compared to depression indicates that the physiological consequences of smoking and nicotine withdrawal may exert a more immediate influence on anxiety symptoms. In this issue of the journal, Shreya et al. have correlated anxiety and depression scores in COPD with the severity of the disease.[16] Anxiety was present in 40.2% of patients, with prevalence rising sharply from 28.6% in mild cases to 76.9% in severe cases according to the BODE index. Depression was observed in 34.7% of the study population; while severe depression affected 2.0% overall, its prevalence spiked to 61.5% in patients with severe COPD. Correlation analyses showed the BODE index had a moderate positive correlation with anxiety scores (r = 0.45, P < 0.001) and a strong correlation with depression scores (r = 0.50, P < 0.001). When compared to global statistics, this study showed a higher prevalence of both anxiety and depression. The reason for the higher prevalence needs to be studied. This may be indirectly related to the younger age group of COPD patients in the Indian subcontinent when compared to Western countries. COPD patients with comorbid anxiety or depression experience more acute exacerbations and incidences of rehospitalization within 12 months. They also carry a higher risk of mortality than COPD patients without these comorbidities. COPD patients with anxiety or depression benefit from pulmonary rehabilitation and cautious use of antidepressants.