Smoking and mental health

Smoking and mental health

Vanessa Jordan
Clinical question

Is cessation of tobacco smok­ing associated with a change in mental health?

Bottom line

Across 6 separate outcomes, there was no evidence to suggest that quitting smok­ing resulted in worsening mental health compared with continuing to smoke.

In addition, there was evidence to suggest that negative mental health symptoms (depression, anxiety, mixed depression and anxiety, and stress) decreased, while positive symptoms (psychological quality of life and quality of so­cial interaction) increased, in people who stopped smoking compared with those who continued to smoke.

The authors found that the pooled effect sizes for anxiety, depression, and mixed anxiety and depression outcomes were similar at around 0.3. Although this could be deemed to be a small‐to‐moderate effect, it is similar in size to that observed in a 2011 meta‐analysis of antidepres­sants for anxiety disorder, which is generally considered to be clinically significant.


All of the included studies were obser­vational; therefore, there is potential for bias. One bias may arise because people with current or past psychological disorders are less likely to achieve abstinence, and are, therefore, likely to be over‐represented in the group who continue to smoke compared with those who stop.

However, the authors primarily compared change in mental health over time between people who stopped smoking and people who did not. If worse mental health at baseline predicted failure to stop smoking, it is likely that by follow‐up it would have improved through regression to the mean, creating a bias that should favour the group continuing to smoke. This bias, therefore, could not explain the apparent benefit of abstinence on improving mental health.


Some people who smoke and some healthcare providers believe smoking can reduce stress and other symptoms related to mental illness, or that quitting smoking can exacerbate mental illness. These beliefs maintain a culture of smoking. However, there are biologically plausible reasons why smoking may worsen mental health through neuroadaptations arising from chronic smoking, which may lead to anxiety, depression and irritability – in which case, smoking cessation may help to improve rather than worsen mental health.

Cochrane Systematic Review

Taylor GMJ, et al. Smoking cessation for im­proving mental health. Cochrane Database Syst Rev 2021, Issue 3. Art. No.: CD013522. DOI: 10.1002/14651858.CD013522.pub2. This review contains 102 trials with a total of 169,500 participants.