Teens’ Tobacco Addiction Faster Than Once Thought

Teens become hooked on tobacco much faster than researchers had previously believed, often after only a few cigarettes, according to a major new study.

And for reasons that are not yet clear, girls become hooked much more easily than boys, according to the study of middle school students in Massachusetts.

Among teenage girls who got hooked, it took only an average of about three weeks from when they started smoking occasionally. Half of the boys who became addicted were hooked within six months, according to the study, which appears in today’s issue of Tobacco Control.

In contrast, researchers believe that it takes about two years and smoking half a pack a day for an adult to become addicted to nicotine.

“Everything we knew [about smoking in teens] was wrong,” said Dr. Joseph R. DiFranza of the University of Massachusetts Medical Center, who led the international team that performed the study.

“I thought that kids who got hooked quickly would be the exception to the rule,” he said. “As it turned out, the kids who did not get hooked quickly were the exception.... Some of these kids were hooked within a few days of starting to smoke.”

“This is not good news,” said epidemiologist Jennifer O’Loughlin of the McGill University Faculty of Medicine in Montreal, who is performing similar research. “If children are getting addicted very early on after very low exposures, it means that prevention is going to become more and more difficult to sell. What we will be talking about is cessation for children--nicotine patches, inhalers, Zyban and everything else.”

Previous studies have shown that 90% of smokers begin before age 19. And for those who started smoking as youths, it requires an average of 18 years to quit. Researchers have thus focused intensive efforts on learning how to prevent smoking among youth, but those efforts have not generally been successful.

In fact, O’Loughlin noted, studies have found that some smoking prevention efforts have, perversely, actually led to smoking increases. “We’re not helping, and there is nothing obvious that can be done” to warn off teenagers, she said.

DiFranza is a well-respected anti-smoking activist whose early research helped demonstrate that the advertising cartoon character Joe Camel was a strong inducement to children to begin smoking, and who documented how cigarettes were readily available to youths in most stores. The latter effort led to new laws to restrict cigarette sales to minors.

In the new study, sponsored by the National Cancer Institute, his team enrolled 679 seventh-grade students (ages 12 and 13) in two small Massachusetts towns. Each student was interviewed three times per year for 30 months. The interviews sought detailed histories of tobacco use, including dates, duration, frequency, quantity and other characteristics. Researchers also looked for any one of 11 signs of nicotine dependence, including smoking in places where you are not supposed to, like school; finding it hard to concentrate without smoking; and feeling irritable when you can’t smoke.

Among the 332 children who reported using tobacco at least once, 40% reported symptoms of dependence.

The median time to onset of symptoms was 21 days for girls and 183 days for boys. When the symptoms began, the median frequency of smoking was only two cigarettes, one day per week.

“It’s startling to find that kids who are smoking two cigarettes per week need help to overcome a dependency on nicotine, but the data shows that youths who showed signs of being hooked at these very low levels of consumption were 44 times more likely to be still smoking at the end of the study,” DiFranza said.

The team coined the term “juvenile onset nicotine dependence” to stress that children are different from adults when it comes to the effects of nicotine. The adolescent brain is still developing, and thus may be more vulnerable to addiction than adults, he speculated.

Supporting that view is a separate study, released Wednesday, in which government researchers said the younger people are when they first try marijuana, the more likely they are to become dependent on illegal drugs later in life.

DiFranza said that animal research has shown that, at doses associated with smoking, nicotine causes brain damage in adolescents that is not seen in adult animals. He noted that “we have begun a new study by the National Institute on Drug Abuse to explore the differences between the sexes.”