Prevalence and Association of Anxiety and Depression with Disease Severity in Chronic Obstructive Pulmonary Disease: A Cross-Sectional Study

Chronic obstructive pulmonary disease (COPD) is currently recognized as the third leading cause of death globally, with nearly 80% of COPD-related mortality occurring in low- and middle-income countries (1). It is a progressive and life-threatening respiratory condition characterized initially by exertional dyspnea and later by frequent exacerbations, declining lung function, and reduced exercise tolerance (2). The prevalence of COPD continues to rise due to increasing tobacco use, air pollution, and lifestyle changes across populations.

 

Beyond the respiratory impairment, COPD is associated with substantial psychological morbidity. Anxiety and depression are among the most frequently observed psychiatric comorbidities in COPD patients, partly due to chronic symptoms, activity limitation, and disability (3). These conditions adversely affect daily functioning and quality of life by influencing physical, emotional, and social domains (4). Furthermore, psychological distress contributes to increased healthcare utilization and economic burden for both patients and caregivers (5,6).

 

Several studies have reported a bidirectional relationship between COPD and psychiatric comorbidities, wherein dyspnea, hyperventilation, and disease-related hyperinflation may amplify anxiety symptoms, forming a vicious cycle of disease perception and physiological arousal (6). Evidence suggests that higher levels of anxiety and depression correlate with increased COPD severity (7–9). Smoking appears to further complicate this association. While smoking is a well-established risk factor for COPD onset, individuals with depressive symptoms may also smoke as a coping mechanism, leading to a self-perpetuating cycle that reinforces both psychiatric symptoms and respiratory dysfunction (10).

 

The prevalence of anxiety and depression in COPD varies widely across studies. A recent meta-analysis estimated the pooled prevalence of depression in COPD to be approximately 27% (10). Despite this, symptoms of anxiety and depression are frequently overlooked in clinical practice, as somatic complaints often overshadow psychiatric manifestations. It has been reported that fewer than one-third of COPD patients with psychiatric comorbidity receive appropriate treatment (11). Early identification and management of anxiety and depression in COPD may therefore offer opportunities to reduce exacerbations, improve treatment adherence, and enhance overall health status.

 

However, there remains a gap in the literature regarding the quantitative relationship between COPD severity, smoking status, and psychological morbidity. The present study was undertaken to evaluate the prevalence of depression and anxiety among COPD patients and to examine their association with disease severity.

 

Aims and Objectives

1.           To estimate the prevalence of depression and anxiety among patients with chronic obstructive pulmonary disease (COPD).

2.           To assess the association between anxiety and depression and the severity of COPD.

 

 

The mean age of the study population was 56.2 ± 8.1 years. The mean smoking index was 19.4 ± 7.2 pack-years. The mean BODE score was 3.1 ± 1.9, while mean HAM-A and MADRS scores were 3.6 ± 4.4 and 11.8 ± 7.3, respectively (Table 1).

 

Table 1. Descriptive Characteristics of the Study Population (n = 180)

 

Based on GOLD staging, Stage II was the most common category, followed by Stage III. The prevalence of mild anxiety was 58.3% and moderate anxiety was 13.9%. Depression was detected in 46.1% of patients, with the majority having mild to moderate symptoms. There was no statistically significant association between age and anxiety or depression. Smoking demonstrated a positive correlation with depression and a weaker correlation with anxiety. BODE index showed a weak but significant correlation with both anxiety and depression. GOLD stage exhibited a moderate positive correlation with depression and a weaker correlation with anxiety (Table 2).

 

Table 2. Correlations Between Smoking, Anxiety, Depression, and Prognostic Factors (n = 180)

NS – Not Significant; * p<0.05; ** p<0.001

Multiple linear regression modeling showed that disease severity (GOLD stage) contributed significantly to smoking behavior, while anxiety and depression had lesser influence (Table 3).

 

Table 3. Multivariate Regression Model: Smoking as Outcome Variable

Model: Smoking = β0 + β1(HAM-A) + β2(MADRS) + β3(GOLD Stage)

Model Fit: R² = 0.31; Adj. R² = 0.27; F = 7.9; p < 0.001*

A separate regression model examining prognosis revealed an inverse association between anxiety and BODE score, while depression exhibited a positive association (Table 4).

 

Table 4. Multivariate Regression Model: BODE as Outcome Variable

Model: BODE = β0 + β1(HAM-A) + β2(MADRS)

Model Fit: R² = 0.21; Adj. R² = 0.18; F = 6.1; p < 0.01*

Regression analysis of GOLD stage demonstrated that depression, rather than anxiety, significantly influenced disease severity (Table 5). Taken together, these findings indicate that depression has a stronger association with smoking, disease severity, and prognosis compared to anxiety among COPD patients.

 

Table 5. Multivariate Regression Model: GOLD Stage as Outcome Variable

Model: GOLD Stage = β0 + β1(HAM-A) + β2(MADRS)

Model Fit: R² = 0.25; Adj. R² = 0.22; F = 7.8; p < 0.01*

Disease severity and prognosis showed stronger associations with depressive symptoms compared to anxiety, suggesting depression may play a more substantial role in disease progression and smoking behavior among COPD patients.

In this study, anxiety and depression were common among patients with COPD, with the majority exhibiting mild symptoms and a smaller proportion experiencing moderate symptoms. These findings are consistent with previous reports indicating a high prevalence of psychiatric comorbidities in COPD populations. Willgoss and Yohannes observed that clinical anxiety was present in 13–46% of COPD outpatients (15). Similarly, Elassal et al. reported anxiety and depression prevalences of 22.5% and 42.5%, respectively (8). Other studies have estimated depression prevalence in COPD ranging between 16.5% and 27.4%, highlighting considerable heterogeneity across settings and severity groups. Depression has been shown to adversely influence outcomes such as exacerbation rates, re-hospitalization, and functional capacity (16).

Anxiety and depression are well recognized to accompany COPD (17). Psychological distress may influence smoking behavior, which in turn worsens respiratory symptoms and accelerates disease progression, forming a self-perpetuating cycle. Smoking may serve as a maladaptive coping strategy for depressive symptoms, while simultaneously acting as a major etiological and aggravating factor for COPD. Interrupting this cycle may have important therapeutic implications. Although pharmacological treatment of anxiety and depression in COPD is similar to that in patients without respiratory disease (18,19), difficulty arises when psychiatric comorbidities influence COPD severity and smoking behavior.

 

In our study, age did not demonstrate significant associations with anxiety, depression, or prognosis. While COPD prevalence increases with age (20), certain studies have reported higher levels of depressive symptoms among younger COPD patients (21). Our larger sample size revealed that smoking had a moderate positive correlation with depression, whereas the correlation with anxiety was weaker. Depression demonstrated a stronger association with disease severity and prognosis compared to anxiety. Although one might expect anxiety to rise with advancing COPD stage (22), our findings suggest that depressive symptoms may play a more prominent role in disease burden within this cohort.

 

Regression analyses further supported these observations. Disease severity (GOLD stage) was significantly associated with smoking behavior, while anxiety and depression were less predictive. Prognostic impairment measured through the BODE index demonstrated significant association with depressive symptoms. GOLD stage was significantly influenced by depression, while anxiety did not show a significant contribution. Collectively, these findings indicate that depression may have a stronger quantitative relationship with smoking, disease severity, and prognosis than anxiety among COPD patients.

The interaction of smoking, COPD, and psychiatric comorbidity has been documented previously. Lou et al. reported that smoking combined with depression accounted for approximately 60% of mortality among COPD patients, while smoking combined with anxiety contributed to nearly 50% (23). Another analysis by the same authors concluded that both anxiety and depression were associated with increased mortality in COPD (24). Goodwin et al. suggested that mood disorders and COPD may share common risk exposures rather than a direct causal pathway (25), whereas Ng et al. proposed that depression in COPD may persist independently of other confounders (26). However, literature examining the quantitative relationships between anxiety, depression, smoking, and COPD severity is limited, and the present study contributes to filling this gap.

 

Limitations

This study has certain limitations. The cross-sectional design precludes establishing causality between psychiatric symptoms, smoking behavior, and disease severity. Only male smokers were included, as women were less willing to disclose smoking history due to cultural sensitivities, limiting generalizability across genders. Although the sample size was larger compared to prior studies, unmeasured confounders such as socioeconomic status, medication adherence, and comorbid medical conditions may influence psychiatric symptomatology. Future research employing longitudinal or interventional designs is warranted to better characterize these associations.

This study highlights the significant burden of anxiety and depression among patients with COPD and suggests that depressive symptoms may have a stronger association with smoking behavior, disease severity, and prognosis than anxiety. Early recognition and targeted management of depression in COPD could provide an opportunity to interrupt the cycle linking psychiatric distress, smoking, and disease progression. Larger, multi-center studies across diverse populations are needed to quantify these associations and guide integrated clinical management strategies.

 

ACKNOWLEDGMENT

Nil.

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