When I smoked 40 years ago, I thought I was calming myself down and ­alleviating anxiety. How wrong I was.

There’s compelling evidence from Oxford University that shows quitting smoking actually improves mental health among people both with and without mental health disorders. The findings reveal that between weeks nine and 24 of stopping smoking, there were significant improvements in anxiety and ­depression scores. The results are so startling that rigorous analysis to assess the changes in mental health were essential.

The study used data from a large smoking cessation study covering 16 countries at 140 centres between 2011 and 2015. It involved adults with or without a psychiatric disorder who smoked. A total of 4,260 participants were included in the analysis, with 55.4% having a history of mental illness.

Angela Wu, PhD student, and lead author from Oxford University, said: “While we are seeing a large decrease of smoking rates over the years in the UK for the general population, this is not the case for people living with mental health conditions. The number of people smoking who also have a mental health ­condition has remained the same since 1993 (approximately 40%).

“We hope our results can help ­motivate policymakers and ­stakeholders to better support smoking cessation in people with mental health conditions.” Co-author, Min Gao, PhD, said their analysis provided “robust evidence about the effects of quitting smoking on mental health”, adding, “Quitting smoking will not worsen and may improve mental health outcomes”.

That’s a very important and ­believable finding. Globally, smoking is the leading cause of preventable illnesses and deaths, with nearly half of all smokers dying from a ­smoking-related disease. Despite expressing a desire to quit, many smokers continue because, for them, smoking is a de-stressor. Professor Paul Aveyard, of Oxford University, said: “Our study joins with others that show that when people stop smoking their mental health improves, whereas those who do not stop smoking have no improvement.”

“Stopping smoking is not easy,” added Angela Wu. “What we do know though is that you are more likely to successfully stop smoking when you are supported, whether that is pharmacologically or behaviourally. There are many alternatives and options to help you quit, such as ­counselling, nicotine replacement therapy – for example patches, gum and sprays – and even trying out electronic cigarettes. Electronic cigarettes do not burn tobacco, which is the most harmful element of smoking cigarettes, but will still give you nicotine.”