'Sleeper effect' leaves children vulnerable to starting smoking years after single cigarette

Cancer Research UK

Children's vulnerability to taking up smoking after trying just a single cigarette can lie dormant for three years or more - according to a new study from Cancer Research UK published today (Thursday 25 May 2006) in the journal Tobacco Control.

The researchers conclude that this lasting predisposition - or ‘sleeper effect’ - may mean it is important to prevent young adolescents from trying even one cigarette.

And also that young people who have tried smoking just once, a number of years previously, should be considered as a key target group for prevention messages and anti-smoking support.

The study of teenage smoking behaviour found that children who smoked just one cigarette by the age of 11 were more than twice as likely to take up smoking over the next few years as those who did not experiment with smoking - even after a gap of up to three years of not smoking.

The findings held true even once factors known to influence the chances of taking up smoking - such as gender, ethnicity, deprivation and parental smoking - were taken into consideration.

The team tracked the smoking behaviour of over 2,000* London school children aged 11 to 16 over five years and measured their nicotine intake by analysing their saliva.

Of the 260 children who, at age 11, said they had tried smoking just once, 18 percent were smokers at age 14. In comparison, 7 percent of children who, at age 11, said they had never smoked had started smoking by age 14.

Lead researcher, Jennifer Fidler who is based at the Cancer Research UK Health Behaviour Unit at University College London, said:

“We know that progression from experimenting with one cigarette to being a smoker can take several years. But for the first time we’ve shown that there may be a period of dormancy between trying cigarettes and becoming a regular smoker - a ‘sleeper effect’ or vulnerability to nicotine addiction.

This has important practical and policy implications. It may be that preventing children from trying even one cigarette is a much more important goal than first thought. And that prevention efforts might be most effective if focussed on pre-secondary school children.

Jennifer Fidler added: “The results also indicate that prior experimentation is a strong predictor of taking up smoking later. And the finding of a ‘sleeper effect’ suggests that health care providers designing targeted campaigns should focus on young teenagers who report having tried cigarettes in the past.”

There are several possible explanations for this ‘sleeper effect’, say the authors. Pathways in the brain may become changed as a consequence of a single exposure to nicotine, increasing vulnerability to smoking triggers such as stress, depression or the school environment at a later date.

Or, experimenting with a cigarette might break down barriers that would otherwise prevent teenagers from taking up smoking - such as insecurities about how to smoke and fear of being caught by adults.

Jean King, director of tobacco control at Cancer Research UK, said: “This study is particularly important because, in 2004, 14 percent of 11 year olds and 62 percent of 15 year olds in England said they had experimented with cigarettes.

“Smoking is the single biggest preventable cause of cancer in the UK. And we know that there’s a ‘hard-to-reach’ group of young smokers that anti-smoking campaigns are failing to connect with. Any research that helps unravel the processes involved in young people becoming addicted to nicotine is key to developing effective and targeted ways to prevent them from starting smoking in the first place.“


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Notes to Editor

Vulnerability to smoking after trying a single cigarette can lie dormant for three years or more. Tobacco Control 2006; 15:2005-9.

*6,000 11 to 16 year olds attending 36 representative schools across South London took part in the annual survey. Only the 2,041 students who provided full data at each of the five years were included in the final analyses.

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