Depression Can Impact Smoking Cessation in Patients With COPD, Study Says

Addressing depressive symptoms may help patients with chronic obstructive pulmonary disease (COPD) achieve smoking cessation, according to a study published in BMC Pulmonary Medicine that suggests a need for assessment of depression and smoking behaviors in this patient population.

The researchers explained that more than 16.4 million people have COPD in the United States, with tobacco causing 90% of cases. They noted that the risk of developing depression doubles for patients who smoke and quadruples in heavy smokers, therefore COPD and depression have a bidirectional relationship.

Despite this relationship, there are minimal studies on the physiological and psychological factors that prevent patients with both COPD and depression from achieving smoking cessation. To improve understanding, the researchers conducted a study aimed at describing and analyzing the factors that contribute to smoking behaviors in people with comorbid COPD and depression, as well as their readiness to change those behaviors.

They assessed these factors through multiple questionnaires completed by participants. The Patient Health Questionnaire-9 (PHQ-9) was used to assess depressive symptoms, with participants rating how they are affected by various depression-related problems from 0 (not at all) to 3 (nearly every day); those with a higher total score had more depressive symptoms. Additionally, current smokers completed the Cigarette Dependence Scale (CDS-12) to assess smoking behaviors; it helped determine cigarette dependence with scores varying from 12, the lowest level of dependence, to 60, the highest level.

The researchers used the Smoking Stage of Change Questionnaire (SSCQ), the Smoking Decisional Balance Questionnaire (SDBQ), and the Processes of Change Questionnaire (PCQ) to assess readiness to change. The SSCQ is a 3-item questionnaire that, based on their smoking status, categorized participants in one of the following change stages: the action, maintenance, preparation, contemplation, or precontemplation stage.

The SDBQ is a 20-item questionnaire that measures the pros and cons of smoking from the respondent's perspective. Participants were asked to rate the importance each statement had on their decision to smoke, ranging from 1 being not important at all and 5 being extremely important. The difference in their scores was calculated, a positive difference indicating that participants saw more pros of smoking and a negative difference that participants saw more cons of smoking.

Lastly, the PCQ is a 20-item questionnaire where participants rated how often the list of experiences happened to them in the past month from 1 (never) to 5 (repeatedly). The mean score was calculated, a higher score indicating engagement in the processes of change.

Woman breaking a cigarette in half | Image credit: zinkevych - stock.adobe.com

The researchers recruited participants from the rural Appalachian region using a convenience sample from February 2020 to November 2020. The researchers recruited those who were 18 years or older, current or former smokers, diagnosed with COPD, and read at a 6th-grade level.

The population consisted of 222 participants: 108 males (48.6%) and 112 females (50.5%). They ranged in age from 32 to 94 years, the mean (standard deviation [SD]) being 64 (9.6) years old. Most participants were white (95%), and over 50% were considered of a lower socioeconomic status. Out of the population, 113 (50.9%) self-reported not having depression, and 101 (45.5%) reported having depression.

Based on the questionnaires, depressive symptom severity ranged from 0 to 27 with a mean (SD) of 7.9 (6.4); only 18 participants (8.1%) reported having no depressive symptoms. Additionally, CDS-12 scores ranged from 23 to 54 with a mean score of 43.82, demonstrating above average cigarette dependence amongst the population.

PCQ scores ranged from 19.05 to 88.2 with a mean score of 45.8. Within the PCQ, social liberation was reported to be the most used process of change (4.72) and stimulus control was the least used (2.56). Also, the SDBQ scores ranged from -30.4 to 21.4 with a mean score of -5.78, indicating that participants saw more cons of smoking.

Lastly, the SSCQ found that 115 participants (51.8%) quit more than 6 months ago, 87 (39.2%) currently smoke, 4 (1.8%) quit within the last 6 months, and 2 (0.9%) never smoked. Of those who smoked, 25 participants (11.3%) reported wanting to quit within the next 30 days, 32 (14.4%) reported wanting to quit within the next 6 months, and 28 (12.6%) reported they were not thinking of quitting. Based on these results, the researchers categorized 115 participants (51.8%) in the maintenance stage, 39 (17.6%) in the contemplation stage, 28 (12.6%) in the precontemplation stage, 17 (7.7%) in the preparation stage, and 4 (1.8%) in the action stage.

The researchers acknowledged their study’s limitations, one being that participants were recruited for the study population using a convenience sample, which is prone to sampling bias. Also, the generalizability of the results to other locations is limited as all participants live in West Virginia.

Despite these limitations, the researchers noted their study demonstrated that focusing on depression control may help assist patients with COPD to achieve smoking cessation. Therefore, they explained that the relationships between smoking, COPD, and depression must be recognized “to address the complex health care needs of this population.”

“Future research should be aimed at adequately assessing, diagnosing, and treating depression to determine the impact on outcomes, specifically related to smoking behaviors and readiness to change,” the authors wrote.

Reference

Floyd, J., Mallow, J., Wang, K. et al. Differences in smoking behaviors and readiness to change for patients with COPD and differing categories of depressive symptoms: a descriptive cross-sectional design. BMC Pulm Med 23, 335 (2023). doi:10.1186/s12890-023-02621-2