Quitting time

Quitting time

For many Canadians, the battle to stop smoking is one that can't seem to be won, but new weapons are being developed in the fight against nicotine addiction
January 19, 2011

Listen to Radio Canada International's interview with Bernard Le Foll

Despite the best intentions of a 34-year-old National Non-Smoking Week, which starts on Jan. 16, one of the most disheartening things for anyone trying to quit smoking is the extremely high likelihood that his or her efforts will end in failure.

“Even with proper treatment, around 70 to 80 percent of people relapse at the end of one year, and without proper treatment, 90 percent do,” says Bernard Le Foll, head of the Translational Addiction Research Laboratory at the Toronto-based Centre for Addiction and Mental Health (CAMH).

With the overwhelming success of failure in mind, Le Foll and his colleagues at CAMH have been trying to come up with new ways for people to kick their nicotine addiction. The theoretical basis for Le Foll’s efforts is the growing understanding that from the body’s perspective, nicotine addiction does not have a single cause but, rather, involves a complex interweaving of various brain biochemistries.

The exciting thing for anyone whose smoking history is littered with failed attempts to quit is that following successful animal trials, two new smoking-cessation approaches will enter human trials this year. One is to see whether transcranial magnetic stimulation of a deep portion of the brain called the insula can help smokers stop.

Insula activity is associated with a variety of emotional states in humans, including anxiety, pain and mood. And, in 2010, CAMH scientists also showed that when a chemical temporarily blocked the insula’s activity, nicotine-addicted rats decreased the amount of nicotine they gave themselves. Led by Le Foll, a CAMH research group is now collaborating with Israeli scientist Abraham Zangen, who has developed an electromagnetic coil that is capable of modulating insula activity. The team plans to image the brains of volunteers to see whether electromagnetic stimulation can temporarily block nicotine’s ability to trigger addictive pathways.

A very different set of experiments is looking at the ability of the drug prazosin to cut down on the urge to smoke. In rats, prazosin decreased the amount of nicotine that addicted animals self-administered. The drug partially blocks the noradrenergic system, which has most famously been linked to the so-called fight-or-flight response to dangerous situations but whose activation has also been associated with a variety of drug addictions.

While the smoking-reduction effectiveness of the two new approaches remains to be seen, Le Foll points out that his addiction work, unlike other areas of medicine, has shown animal laboratory results and human clinical results to be quite similar.
But, unfortunately, researchers have not been able to produce in laboratory animals a self-awareness that long-term nicotine use is fundamentally unhealthy.

“We have not found a way to induce in them something like the awareness ‘you should try to quit this,’” says Le Foll.

In that regard, CAMH will be pushing some very human inducements to stop smoking during National Non-Smoking Week. It is enrolling people in a study in which they will get free doses of Zyban, a drug that has been shown to double the success of people trying to quit smoking. CAMH believes this kind of inducement is needed, since fewer than half the people who try to quit use a drug to help in the fight.

IT’S TIME TO QUIT …

• Forty-three percent of Ontario smokers make a serious attempt to quit smoking at least once over the course of a year.

• Almost 1.7 million Ontarians 18 years and older currently smoke. Of these, approximately 62 percent intend to quit smoking in the next six months and 32 percent intend to quit in the next 30 days.

• Canadian smokers make an average of 3.2 attempts at quitting before they quit for good.

• Children of parents who smoke are 200 to 400 percent more likely to develop asthma.

• Smoking is linked to 30 percent of all cancer deaths in Canada.