Medicine: Why It's So Hard to Quit Smoking

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The panic of a heavy smoker bereft of cigarettes speaks alarmingly of a physiological force at work that is more powerful than mere desire. Not long after taking up the habit, smokers become tolerant of nicotine's effects; as with heroin and cocaine, dependence quickly follows. Tobacco only seems safer because it is not immediately dangerous. Nicotine is not likely, for example, to fatally overstimulate a healthy heart, cause disorienting hallucinations or pack anywhere near the same euphoric punch as many other drugs. "People die with crack immediately," explains Alexander Glassman, a psychopharmacologist at the New York State Psychiatric Institute in Manhattan. "With cigarettes the problems occur 20 years down the line. Nobody lights up their first cigarette and dies."

Like many drugs that affect the nervous system, nicotine at once stimulates and relaxes the body. Because it is inhaled, it takes only seven to ten seconds to reach the brain -- twice as fast as intravenous drugs and three times faster than alcohol. Once there, it mimics some of the actions of adrenaline, a hormone, and acetylcholine, a powerful neurotransmitter that touches off the brain's alarm system, among other things. After a few puffs, the level of nicotine in the blood skyrockets, the heart beats faster and blood pressure increases. Result: smokers become more alert and may actually even think faster. In addition, nicotine may produce a calming effect by triggering the release of natural opiates called beta-endorphins. Thus a smoker literally commands two states of mind -- alertness and relaxation.

Nicotine operates on other parts of the body as well. By constricting blood vessels, it casts a pallor over the face and diminishes circulation in the extremities, often causing chilliness in the arms and legs. It relaxes the muscles and suppresses the appetite for carbohydrates. Since nicotine cannot be stored in the body, smokers maintain a relatively constant level in the blood by continuing to smoke. "Because you take 200 to 400 of these hits a day, there's a lot of reinforcement," says Nina Schneider, a psychopharmacologist at the University of California, Los Angeles. "It's self-administered, and it controls mood and performance. That's what makes it so powerfully addicting."

Despite all this, smoking can be conquered. Although ex-heroin users have reported that tobacco's grip was harder to break than their illicit drug habit, 43 million Americans have managed to quit smoking, mostly succeeding on their own. Increasingly, though, the one-third of all Americans who still smoke are seeking help in antismoking programs, which generally stress that the tobacco habit is a treatable addiction. The best stop-smoking programs, says Thomas Kottke, a senior consultant at the Mayo Clinic in Rochester, Minn., combine several approaches with plenty of long-term support for the struggling nonsmoker. In a study published last week in the Journal of the American Medical Association, Kottke's team compared 39 different regimens -- from self-help books to sensory deprivation -- and found that they all worked about the same. The real key to success, the researchers discovered, lies in the amount of face-to-face encouragement smokers get from physicians, friends and relatives. Even if it takes repeated attempts, the ultimate benefits of quitting far outweigh the anguish that accompanies it.