For many smokers, finding alternatives to overcome their addiction to nicotine is an important aspect when attempting to quit smoking.

But the daunting prospect of quitting can lead to worries about how life without smoking would be.

"The belief that cigarettes are calming is widespread, and some health professionals may deter people with mental health disorders from trying to stop smoking," said researchers from the University of Oxford and the University of Bath, whose work was published at the end of May by the American Medical Association’s JAMA Network.

What they found should further reassure smokers who want to quench the habit but are worried about potentially negative knock-on effects.

"Smoking cessation was associated with significant improvements in anxiety and depression among people with and without psychiatric disorders," the team reported, after conducting a study taking in over 4,200 people in 16 countries.

For many, it can be hard to dispense with routines such as ducking outside the office for a few drags and a chat during the day, or a few relaxing late-night puffs before bedtime.

"Concerns about mental health worsening after quitting are often raised by clinicians and people who smoke," the researchers said.

However, those worries should not put anyone off from trying to quit, the researchers believe.

"Smoking cessation is associated with decreased morbidity risk and improved quality of life at any age, with our analysis adding to evidence that it improves mental well-being too," they said.

Participants included smokers with and without a psychiatric disorder. The research examined the impact of abstaining from nine weeks to 24 weeks among people who "were motivated to quit" but who had smoked 10 or more cigarettes a day during the previous year.