Scientists have confirmed a suspicion held by some smokers but never proven: It could take just a few cigarettes to become addicted.
Some 12- and 13-year-olds showed evidence of addiction within days of their first cigarette, according to research reported this week in the British Medical Association journal Tobacco Control.
“There’s been a suspicion that many people become addicted very quickly, but this is really the first hard evidence that we’ve had that this occurs,” said Dr. Richard Hurt, director of the Nicotine Dependency Unit at the Mayo Clinic.
Experts have tried for years to determine how long people have to smoke before becoming addicted, and “the best answer to date had been 1-2 years,” said Hurt, who was not involved in the study.
He said the findings will help scientists better understand the biology of nicotine addiction and lend more plausibility to the idea that some people may be more genetically susceptible to it than others.
“The really important implication of this study is that we have to warn kids that you can’t just fool around with cigarettes or experiment with cigarettes for a few weeks and then give it up,” said Dr. Joseph DiFranza, who lead the research at the University of Massachusetts. “If you fool around with cigarettes for a few weeks, you may be addicted for life.”
The study, conducted in 1998, followed 681 12- to 13-year-olds in central Massachusetts for a year and tracked their smoking habits.
The researchers did not label any of them addicted because the standard definition of nicotine dependence assumes addiction cannot happen without prolonged heavy smoking. The scientists simply recorded symptoms that indicate addiction.
These include cravings, needing more to get the same buzz, withdrawal symptoms when not smoking, feeling addicted to tobacco and loss of control over the number of cigarettes smoked or the duration of smoking.
Ninety-five of the youths said they had started smoking occasionally — at least one cigarette a month — during the study. The scientists found that 60, or 63 percent, had one or more symptoms of addiction.
A quarter of those with symptoms got them within two weeks of starting to smoke and several said their symptoms began within a few days.
Sixty-two percent said they had their first symptom before they began smoking every day, or that the symptoms made them start smoking daily.
The researchers found that the symptoms began soon after the teens started smoking.
Even though some people who have never smoked on a daily basis can find it hard to quit, the assumption that smokers only become addicted after smoking a lot of cigarettes over a long period of time came from observations that some people can smoke five cigarettes a day for many years and not become addicted, the study noted.
However, it has never been proven that daily smoking is necessary for addiction to begin, the study added.
The scientists suggested there may be three types of smokers: Those who become addicted very quickly, those who get hooked gradually after more regular smoking and those who can smoke lightly or pick up and drop the habit without becoming addicted.
It is also possible that adolescents could be more sensitive to nicotine and that addiction may take longer in people who start smoking at a later age, they added.