Quitting beneficial for mental health outcomes in smokers

Smoking cessation does not appear to worsen the mental health and may even improve it for smokers with and without psychiatric disorders, as reported in a study.

For the study, researchers used data from a large randomized clinical trial, the Evaluating Adverse Events in a Global Smoking Cessation Study. A total of 4,260 participants completed the study and were included in the analysis.

Smoking cessation was defined as 15 weeks of abstinence. Meanwhile, anxiety and depression were evaluated using the Hospital Anxiety and Depression Scale (HADS) at 24 weeks, with a lower score indicating better mental health (range, 0–21).

The mean age of the cohort was 46.5 years, and the majority of the participants were women (58.3 percent), White (71.5 percent), and had a history of mental illness (55.4 percent). At baseline, the mean HADS score was 4.25 for anxiety and 2.44 for depression.

Of the 3,200 participants with complete data, 2,731 continued and 469 stopped smoking. Multivariate analyses showed that compared with continued smoking, cessation was associated with reduced scores for both anxiety (−0.40 point, 95 percent confidence interval [CI], −0.58 to −0.22) and depression (−0.47 point, 95 percent CI, −0.61 to −0.33).

Results of propensity score–adjusted analysis also indicated that smoking cessation had a beneficial effect on anxiety (β, −0.32, 95 percent CI, −0.53 to −0.11) and depression (β, −0.42, 95 percent CI, −0.60 to −0.24).

Meanwhile, instrumental variable analysis was underpowered, and estimates were imprecise. But the investigators stressed that the findings were robust to planned sensitivity and subgroup analyses, with larger effect sizes in participants with a history of mental illness.

The present data may provide reassurance to people who smoke and their clinicians that quitting likely will not worsen and may improve mental health.