the ability to get precise, fingertip dose control," says Henningfield. Achieving just the right blood level is a key to virtually all drug-induced gratification, and the seasoned smoker does this adeptly, by adjusting how rapidly and deeply he or she puffs. "If you get the dose just right after going without cigarettes for an hour or two, there's nothing like it," he says.
The impetus to smoke is indeed, as the tobacco companies put it, for pleasure. "But there's no evidence that smoke in the mouth provides much pleasure," says Henningfield. "We do know that nicotine in the brain does."
For many, nicotine not only gives pleasure, it eases pain. Evidence has mounted that a substantial number of smokers use cigarettes to regulate emotional states, particularly to reduce negative affect like anxiety, sadness, or boredom.
"People expect that having a cigarette will reduce bad feelings," says Thomas Brandon, Ph.D., assistant professor of psychology at the State University of New York at Binghamton. His research found this, in fact, to be one of the principal motivations for daily smokers.
Negative affect runs the gamut from the transitory down times we all have several times a day, to clinical depression. Smokers are about twice as likely to be depressed as nonsmokers, and people with a history of major depression are nearly 50 percent more likely than others to also have a history of smoking, according to Brandon.
Sadly, but not surprisingly, depression appears to cut your chance of quitting by as much as one-half, and the same apparently applies, to a lesser extent, to people who just have symptoms of depression.
According to Alexander Glassman, M.D., professor of psychiatry at the Columbia University College of Physicians and Surgeons, the act of quitting can trigger severe depression in some people. In one study, nine smokers in a group of 300 in a cessation program became so depressed—two were frankly suicidal—that the researchers advised them to give up the effort and try again later. All but one had a history of major depression.
"These weren't average smokers," Glassman points out. All were heavily dependent on nicotine, they smoked at least a pack and a half daily, had their first cigarette within a half hour of awakening, and had tried to quit, on average, five times before. It is possible, he suggests, that nicotine has an antidepressant effect on some.
More generally, suggests Brandon, the very effectiveness of cigarettes in improving affect is one thing that makes it so hard to quit. Not only does a dose of nicotine quell the symptoms of withdrawal (much more on this later), the neurotransmitters it releases in the brain are exactly those most likely to elevate mood.
For a person who often feels sad, anxious, or bored, smoking can easily become a dependable coping mechanism to be given up only with great difficulty. "Once people learn to use nicotine to regulate moods," says Brandon, "if you take it away without providing alternatives, they'll be much more vulnerable to negative affect states. To alleviate them, they'll be tempted to go back to what worked in the past."
In fact, negative affect is what precipitates relapse among would-be quitters 70 percent of the time, according to Saul Shiftman, Ph.D., professor of psychology at the University of Pittsburgh. "We invited people to call a relapse-prevention hot line, to find out what moments of crises were like; what was striking was how often they were in the grip of negative emotions just before relapses, strong temptations, and close calls." A more precise study using palm-top computers to track the state of mind of participants is getting similar results, Shiftman says.
Most relapses occur soon after quitting, some 50 percent within the first two weeks, and the vast majority by six months. But everyone knows of people who had a slip a year, two, or five after quitting, and were soon back to full-time puffing. And for each of them, there are countless others who have had to fight the occasional urge, desire, or outright craving months, even years after the ha