GPs should encourage patients with mental health issues to quit smoking as it can help reduce depression and anxiety by as much as antidepressant treatment, a large meta-analysis has revealed.
UK researchers found people who quit smoking experienced reductions in stress, anxiety and depression as well as improvements in mood and mental health-related quality of life, compared with people who continued to smoke.
Moreover, the benefits of stopping smoking were the same in people with psychiatric disorders as in the general population.
The team said the results should reverse the widely held perception that quitting smoking worsens mental health issues, and encourage GPs to give patients ‘maximum support’.
The researchers analysed 26 studies that captured formal assessments of mood over time in smokers who either continued smoking or stopped.
The results, published in the BMJ, showed measures of anxiety, depression, mixed anxiety and depression and stress all significantly decreased between baseline and follow-up in people who quit compared with people who continued to smoke.
For anxiety, the standardised mean difference in symptom scores was -0.37 for quitting, compared with continuing to smoke, while for depression the mean difference was -0.25 and for mixed anxiety and depression it was -0.31.
The team noted the summary effect size for depression was greater than effect estimates seen in previous meta-analyses of antidepressant medications in patients with mild-to-severe depression, where they ranged from -0.17 to -0.11, while for anxiety it was similar to the effects in meta-analyses of antidepressants in generalised anxiety disorder, in which they ranged from -0.23 to -0.50.
The team also found significant improvements in mood and mental-health-related quality of life among quitters compared with continuing smokers.
When the researchers looked at the effects in different populations, they found improvements in these mental health outcomes were the same for patients with psychiatric disorders as for general medical or surgery populations of patients, as well as for the general population without mental health disorders.
The authors concluded: ‘Whether or not smoking cessation directly causes the observed improvement in mental health, there are direct clinical implications. Smokers can be reassured that stopping smoking is associated with mental health benefits. This could also overcome barriers that clinicians have toward intervening with smokers with mental health problems.’
Co-author Professor Paul Aveyard, professor of behavioural medicine at the University of Oxford and a GP in Solihull, told Pulse he hoped the findings would help GPs to feel more confident in encourage people to quit smoking – particularly those with serious mental illness.
Professor Aveyard said: ‘Psychiatrists and GPs like me tend to worry that if we encourage people to stop smoking this will make a person’s serious mental disorder worse. But what our study seems to show is that if they stop smoking it may indeed improve.’
He added: ‘If you look at what’s happened with the smoking prevalence in the general population, it’s come down in recent years – but in people with mental health disorders it hasn’t. I think what’s important is that GPs do refer those people to maximum support and give effective medication to make stopping smoking that bit easier for those people.’
Dr Gabriel Ivbijaro, president-elect of the World Federation of Mental Health and a GP in Walthamstow, said: ‘The implication for this is that primary care and CCGs should double their efforts in co-ordinating and promoting smoking cessation as one of the holistic ways of promoting and improving mental health outcomes.’
Dr Alex Bobak, a GPSI in smoking cessation practicing in south-west London, said: ‘There is a long-held belief that it’s not worth helping them stop smoking when actually it is the thing that it is most worth helping – both from the point of view of physical health and, as the paper says, for mental health as well.’