Just one cigarette can lead to addiction: study
Last Updated: Wednesday, July 4, 2007 | 2:41 PM ET
CBC News
Some young people show signs of addiction after inhaling just one cigarette, say U.S. researchers.
In a four-year study of more than 1,200 sixth-grade students in Massachusetts, 10 per cent of those who smoked were addicted within two days of first inhaling, and another 25 per cent were hooked within a month.
Among the 217 students who had smoked, just over half became addicted.
Symptoms of nicotine addiction can appear when young people are smoking as little as one cigarette per month, the study found.
At first, one cigarette will relieve the craving produced by nicotine withdrawal for weeks, researchers said.
But as tolerance to nicotine builds, the smoker must smoke ever more frequently to cope with withdrawal.
"The most susceptible youths lose autonomy over tobacco within a day or two of first inhaling from a cigarette," University of Massachusetts Medical School researchers wrote in an article published in the July issue of the Archives of Pediatric and Adolescent Medicine.
Students were interviewed about smoking and symptoms of addiction, such as difficulty quitting, strong urges to smoke, or nicotine withdrawal symptoms such as cravings, restlessness, irritability, and trouble concentrating.
"Laboratory experiments confirm that nicotine alters the structure and function of the brain within a day of the very first dose. In humans, nicotine-induced alterations in the brain can trigger addiction with the first cigarette," Joseph R. DiFranza, a professor of family medicine & community health, said in a news release.
"Nobody expects to get addicted from smoking one cigarette," he said.
Addiction-related changes in the brain caused by nicotine are permanent and remain years after a smoker has quit, said DiFranza.
That's why one cigarette can trigger an immediate relapse in an ex-smoker, he said. It also explains why an ex-smoker who relapses after many years of abstinence can't keep the craving away by smoking one cigarette a month.
The study was funded by the U.S. National Institute on Drug Abuse.
