It's the time of year when people resolve to make changes in their lives. And we probably all know someone -- it might even be ourselves -- who vowed to quit smoking.
We also all know someone who stopped for a few days then lit back up. Here's a closer look at one of the most difficult resolutions to keep: "I vow to quit smoking."
According to a 2006 report by the Centers for Disease Control and Prevention, 41 percent of smokers try to quit at least once during the year. But only about 10 percent actually succeed.
"For some people, quitting is one of the hardest things they will ever do in their lives," says Dr. Marc Manley, medical director for population health at Blue Cross and Blue Shield of Minnesota, in Minneapolis.
Smokers trying to quit are up against one of the most addictive substances around.
An example of nicotine's powers: In 2007, researchers conducted an experiment in which they first allowed squirrel monkeys to give themselves a nicotine injection by pressing a lever.
As time went on, the monkeys had to press the lever more times to get the drug. The animals would slap the lever for hours to get their fix, the researchers found, and some were willing to hit the lever as many as 600 times for a burst of the drug.
Manley says quitting is possible, but "it is not to be taken lightly. It takes work, planning and persistence."
Many people quit a few times before it sticks, he adds. A statistic often quoted is that it takes seven times to quit before a person succeeds, but, in fact, researchers don't know the average number of attempts people make before kicking the habit for good.
People trying to quit do better when they have some sort of medication.
Of those going cold turkey with no medical assistance, studies suggest, about 5 percent will succeed, Manley says, whereas the number of successful quitters who use an anti-smoking drug averages about 30 percent. (Depending on the study design, "quitting" might be defined as staying smoke-free for months or years.)
Drugs that help people quit are of two varieties: One replaces the nicotine that smokers get from cigarettes. This comes in the form of gum, a lozenge, patch, nasal spray or inhaler. The others are drugs that mimic nicotine's actions in the brain such as Chantix (varenicline) and Zyban (bupropion). These usually require a prescription.
"There isn't a real clear winner which is best," Manley says.
Nicotine replacers and medications help stave off withdrawal symptoms that quitters inevitably feel. "The worst symptoms usually last one to two weeks," Manley says. "But ... former smokers have to think of themselves as a nicotine addict for life."
Recent research suggests that a person's genes may influence how easy it is to quit and what therapy works best.
A study published in September in the journal Biological Psychiatry reported that people with a certain form of a gene called CYP2B6 don't benefit from bupropion as much as people with a different variation of that gene.
Researchers also have found that the precise message the smokers hear when they're urged to quit appears to be important. Benjamin Toll, a researcher at Yale University School of Medicine, found that when smokers who are trying to quit using medications are presented with encouraging mottoes such as, "When you quit smoking, you save your money, you look healthy," they are more likely to abstain from smoking than people who are told, "If you continue smoking, you waste your money, you look unhealthy."
Toll's study tracked 170 quitters on bupropion. People watched stop-smoking videos and got handouts, water bottles and air fresheners with reminders on them to not smoke. Reminders were either positive or negative. Six months later, 32 percent of the group given positive messages were not smoking, compared with 25 percent of the other group.
Counseling is also important for a quitter. "You're about to break up with your best friend: your cigarettes," Manley says. Many states have telephone counseling available for people who want someone to talk to or want to get some encouragement.
A supportive environment -- being unable to smoke at work, a home in which no smoking is allowed -- "goes a long, long way in helping people succeed," Manley says.
Finally, he says, if a quitter doesn't succeed the first time, "Keep at it. Be persistent. You can do it."
Mary Beckman writes for the Los Angeles Times.