Smoking Cessation May Improve Mental Health in Patients With Anxiety, Depression

Smoking cessation sustained for at least 15 weeks is associated with improvement in mental health of individuals with and without psychiatric disorders, according to study findings published in JAMA Network Open. 

Previous research has shown an association between the improvement of mental health symptoms, such as anxiety symptoms, and smoking cessation, compared with continuing to smoke. This contradicts a common misconception by patients who associate smoking with feelings of stress relief and other mental health benefits.

To assess mental health changes following smoking cessation, researchers used data from US-based participants from the Evaluating Adverse Events in a Global Smoking Cessation Study (EAGLES), a large, randomized clinical trial that took place in 16 countries at 140 centers between 2011 and 2015. For their secondary analysis, the researchers used 3 confirmatory coprimary analytical approaches: multivariable Tobit regression, propensity score matching, and IV analysis.

Primary outcomes include anxiety and depression, measured using the Hospital Anxiety and Depression Scale (HADS) and administered at baseline and through week 24. Smoking cessation was defined as maintaining continuous abstinence from smoking between weeks 9 and 24.

The researchers recruited 4,260 individuals aged 18 to 75 who had smoked 10 or more cigarettes per day in the past year and were motivated to quit smoking. At baseline, participants were a mean age of 46.5; 58.3% were women; 71.5% were White; 55.4% had a history of mental illness; and, 21.7% were currently prescribed psychotropic medication.

At baseline, the mean (SD) HADS score was 4.25 (3.68) for anxiety and 2.44 (2.91) for depression.

Using the multivariable Tobit regression model, the researchers found that patients who stopped smoking had lower scores for anxiety, compared with patients who did not discontinue smoking (unadjusted: -0.28 points; 95% CI, -0.41 to -0.14 points; adjusted: -0.40 points; 95% CI, -0.58 to -0.22 points).

Similar results were seen in HADS score for depression (unadjusted: -0.29 point; 95% CI, -0.40 to -0.19 points; adjusted: -0.47 points; 95% CI, -0.61 to -0.33 points).

Compared with patients who were randomly assigned to receive placebo, those who were randomly assigned to an active drug did not experience significantly different mental health outcomes. Propensity score matching analysis revealed that patients who stopped smoking had improved mental health, compared with patients who did not quit smoking in both outcomes (depression: β, -0.42; 95% CI, -0.60 to -0.24; anxiety: β, -0.32; 95% CI, -0.53 to -0.11).

Results of a sensitivity analysis performed to assess the variations in HADS scores between individuals receiving vs not receiving bupropion supported the findings from the other analyses. The HADS scores for patients who quit smoking without a psychiatric history (depression, -0.32 points; 95% CI, -0.48 to -0.15 point; anxiety, -0.29 points; 95% CI, -0.50 to -0.08 points) had lower scores, compared with patients with a psychiatry history (depression, -0.60 points; 95% CI, -0.82 to -0.38 point; anxiety, -0.48 point; 95% CI, -0.76 to -0.20 point).

Overall, by 6 months, the HADS score for patients that quit smoking were 0.40 point lower for anxiety and 0.47 point lower for depression after adjusting for various potential confounding variables.

The main limitation of this study was a significant loss to follow-up among participants and lack of robustness in the instrument used to randomize the groups, resulting in inconclusive results from the IV analysis. In order to achieve clinically significant findings, future studies may need to consider a larger sample size.

“Smoking cessation is associated with decreased morbidity risk and improved quality of life at any age, with our analysis adding to evidence that it improves mental well-being too,” the researchers concluded.

Overall, this study provides evidence that smoking cessation is associated with improvements in mental health outcomes for individuals with and without psychiatric disorders.

Disclosure: A study author has declared affiliations with biotech, pharmaceutical, and/or device companies. Please see the original reference for a full list of authors’ disclosures.