Scientists have shed more light on why smokers find it so hard to give up.
Smokers may enjoy socialising less when giving up
A team at Goldsmiths College, London has concluded that being deprived of nicotine makes normally pleasurable things less enjoyable.
The research, revealed at the British Psychological Society's Annual Conference, concludes that this may be the reason so many smokers relapse.
But anti-smoking groups point out smokers can still give up successfully using nicotine replacement therapy.
The research team recruited 200 smokers, all of whom smoked more than 10 cigarettes a day.
The volunteers were tested twice, each time after they had refrained from smoking for 12 hours.
On each occasion they received a lozenge that either contained nicotine or was a placebo.
They were all given a questionnaire assessing how pleasurable they expected certain activities to be, like eating their favourite food, or going out for the evening.
The researchers found that the smokers deprived of nicotine expected these things to be less pleasurable than those who were given it.
The volunteers were also asked to sort cards, and offered money for doing it.
The nicotine-deprived volunteers did not respond to the incentive as well as the others.
Dr Lynne Dawkins, who the led the research, said: "These results led us to conclude that giving up smoking must make many other things in life much less fun."
The researchers also found that smokers who had not been given nicotine found it harder to resist an impulsive urge - not looking at something that they were specifically told to ignore.
Although the team have yet to apply their findings outside the laboratory, Dr Dawkins thinks this may be why the urge to reach for a cigarette is so strong.
"When smokers are faced with a situation where they're tempted, they may find it harder to resist a cigarette simply because they can't resist the impulsive urge to smoke".
Dr Dawkins resists any suggestion that the research will put smokers off giving up.
"I think by discovering this, we can turn it into a positive - it allows us to understand practically why people quit.
"The next stage is for us to identify why some people find it harder than others, and we've already started that research."
Deborah Arnott, Director of Action on Smoking and Health (ASH), adds:
"There is a danger this research can be seen as negative. But what it does really is remind people of something we already know, which is that it's the nicotine you're addicted to, not the smoking.
"So if you use nicotine-replacement therapy to help you give up, you stand a much better chance".