Sustained smoking cessation protects against depression in COPD patients

Sustained smoking cessation among patients with chronic obstructive pulmonary disease (COPD) has been linked to substantially reduced risk of subsequent depression, according to a study.

Researchers used data from the National Health Insurance Service–National Health Screening Cohort and identified 5,671 adults with newly diagnosed COPD. These participants were grouped based on their smoking status before and after diagnosis, as follows: continual smokers, short-term quitters (<2 years), long-term quitters (≥2 years), and never smokers.

Over 48,621 person-years of follow-up, 603 cases of incident depression were documented. Cox proportional hazards models showed that the risk of incident depression was 34-percent lower among long-term quitters vs continual smokers (adjusted hazard ratio [aHR], 0.66, 95 percent confidence interval [CI], 0.45–0.97).

The association between sustained smoking cessation and reduced depression risk was strongest among patients with severe COPD (aHR, 0.40, 95 percent CI, 0.20–0.82) and was consistently observed across subgroups defined by male sex, age <65 years, lower comorbidity burden, higher household income, and BMI <25 kg/m².

The findings highlight the importance of long-term smoking cessation to improve both mental health and overall outcomes of COPD patients, according to the researchers. Long-term smoking cessation should be included as a core element of comprehensive COPD management in routine clinical practice worldwide, they added.