Change in mental health after smoking cessation: systematic review and meta-analysisBMJ 2014; 348 doi: https://doi.org/10.1136/bmj.g1151 (Published 13 February 2014) Cite this as: BMJ 2014;348:g1151
- Gemma Taylor, doctoral researcher12,
- Ann McNeill, professor of tobacco addiction23,
- Alan Girling, reader in medical statistics1,
- Amanda Farley, lecturer in epidemiology12,
- Nicola Lindson-Hawley, research fellow24,
- Paul Aveyard, professor of behavioural medicine24
- 1School of Health and Population Sciences, University of Birmingham, Birmingham B15 2TT, UK
- 2UK Centre for Tobacco and Alcohol Studies, Epidemiology and Public Health, University of Nottingham, NG5 1PB, UK
- 3Institute of Psychiatry, King’s College London, London SE5 8AF, UK
- 4Department of Primary Care Health Sciences, University of Oxford, Oxford OX1 2ET, UK
- Correspondence to: G Taylor and P Aveyard
- Accepted 21 January 2014
Objective To investigate change in mental health after smoking cessation compared with continuing to smoke.
Design Systematic review and meta-analysis of observational studies.
Data sources Web of Science, Cochrane Central Register of Controlled Trials, Medline, Embase, and PsycINFO for relevant studies from inception to April 2012. Reference lists of included studies were hand searched, and authors were contacted when insufficient data were reported.
Eligibility criteria for selecting studies Longitudinal studies of adults that assessed mental health before smoking cessation and at least six weeks after cessation or baseline in healthy and clinical populations.
Results 26 studies that assessed mental health with questionnaires designed to measure anxiety, depression, mixed anxiety and depression, psychological quality of life, positive affect, and stress were included. Follow-up mental health scores were measured between seven weeks and nine years after baseline. Anxiety, depression, mixed anxiety and depression, and stress significantly decreased between baseline and follow-up in quitters compared with continuing smokers: the standardised mean differences (95% confidence intervals) were anxiety −0.37 (95% confidence interval −0.70 to −0.03); depression −0.25 (−0.37 to −0.12); mixed anxiety and depression −0.31 (−0.47 to −0.14); stress −0.27 (−0.40 to −0.13). Both psychological quality of life and positive affect significantly increased between baseline and follow-up in quitters compared with continuing smokers 0.22 (0.09 to 0.36) and 0.40 (0.09 to 0.71), respectively). There was no evidence that the effect size differed between the general population and populations with physical or psychiatric disorders.
Conclusions Smoking cessation is associated with reduced depression, anxiety, and stress and improved positive mood and quality of life compared with continuing to smoke. The effect size seems as large for those with psychiatric disorders as those without. The effect sizes are equal or larger than those of antidepressant treatment for mood and anxiety disorders.
The work was undertaken by the UK Centre for Tobacco and Alcohol Studies, a UK Clinical Research Collaboration, Public Health Research: Centre of Excellence. We thank Yen Fu Chen (research fellow, School of Health and Population Sciences, University of Birmingham) and Taina Taskila (senior researcher, Work Foundation Alliance Limited).
Contributors: GT was involved in study design, systematic search, pilot of data extraction form, title/abstract scanning, obtaining full text, determining eligibility of articles, correspondence with authors of eligible papers, quality checks of included articles, data extraction, data synthesis/analysis, data interpretation, literature search, and writing manuscript and appendix 1. AMcN was involved in study design, pilot of data extraction form, determining eligibility of articles, quality checks of included articles, data extraction, data interpretation, literature search, and writing manuscript and appendix 1. AG was involved in determining eligibility of articles, data extraction, data synthesis/analysis, data interpretation, and writing manuscript and appendix 1. AF was involved in data synthesis/analysis, data interpretation, writing manuscript and appendix 1. NL-H was involved in title/abstract scanning and writing manuscript. PA was involved in study design, systematic search, pilot data of extraction form, title and abstract scanning, determining eligibility of articles, quality checks of included articles, data extraction, data synthesis/analysis, data interpretation, literature search, writing manuscript and appendix 1. GT and PA are guarantors.
Funding: This study was funded by a National Coordinating Centre for Research Capacity Development scholarship. Funding from British Heart Foundation, Cancer Research UK, Economic and Social Research Council, Medical Research Council, and the Department of Health, under the auspices of the UK Clinical Research Collaboration, is gratefully acknowledged. GT is funded by a National Coordinating Centre for Research Capacity Development scholarship. NL-H is funded by a research grant awarded by the National Institute for Health Research Health Technology Assessment HTA programme (09/110/01).
Competing interests: All authors have completed the ICMJE uniform disclosure form at www.icmje.org/coi_disclosure.pdf and declare: GT has received grants and personal fees from a National Coordinating Centre for Research Capacity Development scholarship, during the conduct of the study; and personal fees from UK Centre for Tobacco and Alcohol Studies, outside the submitted work. AMcN has received grants from UK Centre for Tobacco and Alcohol Studies, outside the submitted work. AF has received grants from National Prevention Research Initiative, during the conduct of the study; and sat on the professional development group for NICE guidance on stopping smoking in secondary care. NL-H has received personal fees from manufacturers of smoking cessation aids, outside the submitted work; and manages an NIHR HTA funded trial of nicotine patch preloading. The nicotine patches for the trial are provided free of charge by GlaxoSmithKline (GSK). GSK have no other involvement in the trial. PA has received personal fees from Pfizer, grants and personal fees from McNeil, outside the submitted work.
Ethical approval: None required.
Data sharing: Statistical formulas and dataset are available from corresponding authors.
Transparency: GT affirms that the manuscript is an honest, accurate, and transparent account of the study being reported; that no important aspects of the study have been omitted; and that any discrepancies from the study as planned (and, if relevant, registered) have been explained.
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