Smokers with depression who successfully quit smoking using stop smoking services may see an improvement in their mental health, according to new research, funded by Cancer Research UK and published in Annals of Behavioural Medicine.
Researchers at Kings College London and the Charles University in Prague who studied people attending a stop smoking clinic in the Czech Republic, found that successful quitters had a considerable improvement in their depression.
And two-thirds (66.3 per cent) of those who had moderate or severe depression when smoking described no or minimal symptoms during a one-year follow up.
The researchers also found that all those who received the specialist behavioural support and medication provided by the clinic, were more likely to remain smoke free for a year if they went back for repeat visits.
But they noted that people with depression were still less likely to quit successfully than those without. This highlights that different groups can benefit to different extents from the same support, and suggests that people with mental health problems need extra help.
Smoking rates among people with mental health conditions are more than double those of the general population (approximately 40% vs. 20%). It's estimated that of the 9.6 million adult smokers in the UK, around three million have a mental health condition.
Smoking is the single biggest factor contributing to a lower life expectancy associated with a mental health condition - a decrease of about 10-20 years compared to the general population.
Dr Leonie Brose, a Cancer Research UK fellow based at King's College London and senior author of the publication, said: "Our study shows that stop smoking services can be very effective at supporting people with depression, and that increased visits greatly improve the success of quit attempts.
"The findings also suggest that giving up smoking may improve depressive symptoms, improving mental as well as physical health.
"While there's been an overall fall in smoking rates in recent decades, there hasn't been the same decline among people with mental health problems.
"We hope that this research will help boost mental health services and stop smoking services in the UK giving effective support and medication to those who need it most."
This new study highlights just how vital stop smoking services are. In England, smokers who use similar services are around three times more likely to quit successfully than those using no support at all.
The research is published as stop smoking services across England face continued budget cuts.
Local councils run the services, but funding comes from Westminster. Year on year, cuts to the Public Health Grant from HM Treasury have placed considerable strain on local councils, and budgets for stop smoking services have been repeatedly slashed since 2013.
Alison Cox, Cancer Research UK's director of cancer prevention, said: "This study draws attention to a vulnerable group who need more specialist support in their attempts to give up smoking.
"When it comes to tobacco-related illness, reducing the dramatic difference in the health of social groups is a really important issue.
"Because of this, it's vital to protect funding for specialist stop smoking services, which remain the most effective route to quitting."