The Tipping Point: How Little Things Can - By Gladwell, Malcolm Page 0,90

four times a day, injecting a huge dose all at once. Smokers, on a lesser scale, do the same. They get a jolt from a cigarette, then pause, then get another jolt. The patch, though, gives you a steady dose of the drug over the course of the day, which is a pretty boring way to ingest nicotine. The patch seems no more a Tipping Point in the fight against the smoking epidemic than SlimFast milkshakes are a Tipping Point in the fight against obesity. Is there a better candidate?

I think there are two possibilities. The first can be found in the correlation between smoking and depression, a link discovered only recently. In 1986, a study of psychiatric outpatients in Minnesota found that half of them smoked, a figure well above the national average. Two years later, Columbia University psychologist Alexander Glassman discovered that 60 percent of the heavy smokers he was studying as part of an entirely different research project had a history of major depression. He followed that up with a major study published in the Journal of the American Medical Association in 1990 of 3,200 randomly selected adults. Of those who had at some time in their lives been diagnosed with a major psychiatric disorder, 74 percent had smoked at some point, and 14 percent had quit smoking. Of those who had never been diagnosed with a psychiatric problem, 53 percent had smoked at some point in their life and 31 percent had managed to quit smoking. As psychiatric problems increase, the correlation with smoking grows stronger. About 80 percent of alcoholics smoke. Close to 90 percent of schizophrenics smoke. In one particularly chilling study, a group of British psychiatrists compared the smoking behavior of a group of twelve to fifteen year olds with emotional and behavioral problems with a group of children of the same age in mainstream schools. Half of the troubled kids were already smoking more than 21 cigarettes a week, even at that young age, versus 10 percent of the kids in the mainstream schools. As overall smoking rates decline, in other words, the habit is becoming concentrated among the most troubled and marginal members of society.

There are a number of theories as to why smoking matches up so strongly with emotional problems. The first is that the same kinds of things that would make someone susceptible to the contagious effects of smoking—low self esteem, say, or an unhealthy and unhappy home life—are also the kinds of things that contribute to depression. More tantalizing, though, is some preliminary evidence that the two problems might have the same genetic root. For example, depression is believed to be the result, at least in part, of a problem in the production of certain key brain chemicals, in particular the neurotransmitters known as serotonin, dopamine, and norepinephrine. These are the chemicals that regulate mood, that contribute to feelings of confidence and mastery and pleasure. Drugs like Zoloft and Prozac work because they prompt the brain to produce more serotonin: they compensate, in other words, for the deficit of serotonin that some depressed people suffer from. Nicotine appears to do exactly the same thing with the other two key neurotransmitters—dopamine and norepinephrine. Those smokers who are depressed, in short, are essentially using tobacco as a cheap way of treating their own depression, of boosting the level of brain chemicals they need to function normally. This effect is strong enough that when smokers with a history of psychiatric problems give up cigarettes, they run a sizable risk of relapsing into depression. Here is stickiness with a vengeance: not only do some smokers find it hard to quit because they are addicted to nicotine, but also because without nicotine they run the risk of a debilitating psychiatric illness.

This is a sobering fact. But it also suggests that tobacco may have a critical vulnerability: if you can treat smokers for depression, you may be able to make their habit an awful lot easier to break. Sure enough, this turns out to be the case. In the mid 1980s, researchers at what is now the Glaxo Wellcome pharmaceutical firm were doing a big national trial of a new antidepressant called bupropion when, much to their surprise, they began getting reports about smoking from the field. “I started hearing that patients were saying things like, ‘I no longer have the desire to smoke,’ or ‘I’ve cut down on the number of cigarettes I’m smoking,’ or ‘Cigarettes don’t taste as good anymore,’” said Andrew