Writing online in the British Medical Journal (BMJ), researchers said smokers who believe their habit relieves stress and depression are mistaken. The effect of quitting was the same, if not bigger, than for the tablets, they said.
The team, of the univer-sities of Birmingham and Oxford, and King's College London, analysed 26 studies.They found: "Smoking cessation is associated with reduced depression, anxiety, and stress and improved positive mood and quality of life compared with continuing to smoke."
Participants in the studies smoked about 20 cigarettes a day and were followed up for an average of six months.
The researchers said health professionals reluctant to offer stop-smoking advice to people with mental health disorders for fear of making them worse should be encouraged by the findings.
Professor Paul Aveyard, of the University of Oxford, said: "For people with chronic mental health problems, stopping smoking might be an effective treatment."