Results showed that positivity and psychological quality of life improved after stopping smoking. Christopher Meredith/Flickr

Many people start smoking to cope with stress and get some peace of mind. However, according to a new study, kicking the habit is the best way to boost mental health.

Though cigarettes contain about 4,000 toxic chemicals and have long been linked to many deadly diseases, including heart disease, lung cancer and stroke, many prefer continuing smoking, mainly thinking that it can help relieve stress.

For the study, researchers from three Universities in the UK- King's College London, Oxford and Birmingham looked at 26 studies, to analyse which activity- stopping smoking or continuing the habit- is best for mental peace.

The studies included both healthy adults and people with chronic psychiatric or physical conditions, aged around 44, who smoked around 20 cigarettes daily. The data also included details about the participants' mental health before and after they stopped smoking.

Results showed that positivity and psychological quality of life improved after one stopped smoking. Additionally, it also helped manage anxiety, depression, and stress better than while engaging in the habit.

Till date, helping people with mental disorders to quit smoking has been a big challenge to the doctors due to the concern that it can intensify their mental conditions. However, in the new study,  both the groups benefited equally from their decision to quit smoking.

"Smoking cessation is associated with reduced depression, anxiety, and stress and improved positive mood and quality of life compared with continuing to smoke," the authors, while concluding their study, wrote. "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 study has been published in BMJ.

Many psychologists have revealed similar facts in the past. According to researchers from the University of East London, smoking is a psychological addiction and does not help relieve stress. On the other hand, nicotine in the cigarettes can contribute to anxiety and tension.  Psychologist Andy Parrott and colleagues looked at 30 international studies and found that smoking helps feel good by stopping the withdrawal symptoms. "Most smokers mistakenly claim cigarettes are helping to relieve stress," Parrott, told Daily Mail.

"Regular smokers need nicotine to maintain normal moods as they suffer tension between cigarettes," he added later.