Quitting smoking improves mental health
Quitting smoking is associated with an improvement in mental health, according to a study involving researchers from King’s College London and the universities of Oxford and Birmingham, published in the British Medical Journal.
The researchers say the effect sizes are equal or larger than those of antidepressant treatment for mood and anxiety disorders.
It is well known that stopping smoking substantially reduces major health risks, such as the development of cancers, cardiovascular and respiratory diseases. But the association between smoking and mental health is less clear cut.
Many smokers want to stop but continue smoking as they believe smoking has mental health benefits. And health professionals are sometimes reluctant to deal with smoking in people with mental disorders in case stopping smoking worsens their mental health.
Professor Ann McNeill from the UK Centre for Tobacco and Alcohol Studies at King’s College London, and co-author of the study says: “We found that stopping smoking was associated with improved mental health, compared with continuing to smoke. Whilst smoking rates in the general population continue to decrease and are now at approximately 20 percent, smoking rates for people with mental health problems are around twice this, and even higher in those with more severe disorders. This significantly contributes to the lower life expectancy of this group. This finding should be encouraging news for clinicians who would like to promote smoking cessation to all patients, including those with mental health problems.”
The researchers set out to investigate changes in mental health after smoking cessation compared with continuing to smoke.
They analysed the results of 26 studies of adults that assessed mental health before smoking cessation and at least six weeks after cessation in the general population and clinical populations (patients with chronic psychiatric and/or physical conditions). Differences in study design and quality were taken into account to minimise bias.
Measures of mental health included anxiety, depression, positivity, psychological quality of life, and stress. Participants had an average age of 44, smoked around 20 cigarettes a day, and were followed up for an average of six months.
The research team found consistent evidence that stopping smoking is associated with improvements in depression, anxiety, stress, psychological quality of life, and positivity compared with continuing to smoke.
The strength of association was similar for both the general population and those with mental health disorders. And there was no evidence that study differences could have skewed the results.
Funding: The study was funded by the National Coordinating Centre for Research Capacity Development, with additional support from the British Heart Foundation, Cancer Research UK, Economic and Social Research Council, Medical Research Council, Department of Health, under the auspices of the UK Clinical Research Collaboration.
For further information, please contact Seil Collins, Press Officer, Institute of Psychiatry, King's College London +44(0)207 848 5377 / seil.collins@kcl.ac.uk
Paper reference: Taylor, G. et al. ‘Change in mental health after smoking cessation: systematic review and meta-analysis’ published in BMJ doi: http://dx.doi.org/10.1136/bmj.g1151