CHAPTER 5

Nicotine`s Journey to the Brain

Former smokers have claimed that kicking the nicotine habit was more difficult than quitting hard drugs. Here's why.

PART 1 Early Exposure

Heavy smokers who are addicted will face a tough battle when they quit. Researchers are gathering evidence about why some people are more likely to become addicted to nicotine than others. Some smokers say that their habit began with their first cigarette. Others can barely stand the sensation of that first cigarette—but later fall into the habit. And most people never smoke regularly. The reason seems to be partly genetic, as is the case with most substance abuse. But the age at which a person begins smoking, the smoker's mental and emotional health, and the family's smoking habits are also involved. READ MORE

Researchers in Canada are zeroing in on structural differences in the brain that may account for the fact that some people are hooked after one cigarette and others aren't. By blocking certain nicotinic receptors with drugs, they were able to change the response to nicotine in laboratory rats. Rats that were addicted suddenly had a negative response when exposed to nicotine. They hope that further study may help them create a medication that blocks these nicotinic receptors in humans. But their current theory is that naturally-occurring differences in the way our receptors are structured must be connected to the chances of becoming addicted soon after that first cigarette. Other studies have shown that earlier exposure to nicotine leads to greater risk and severity of dependence. LESS

PART 2 The More You Smoke

True or False?

“Light” cigarettes are safer

The longer you smoke, and the more you smoke each day, the more severe nicotine addiction becomes. Once your brain and body grow accustomed to your intake of nicotine, you start developing additional receptors where the nicotine can bind and trigger the release of dopamine in your brain. Your craving for nicotine will intensify and become more frequent. Ignoring the cravings brings on unpleasant withdrawal symptoms. And what alleviates those? Yes, more nicotine. READ MORE

When medical professionals try to assess a smoker's health risks and the difficulty he or she might have in quitting, they calculate the person's pack years. This simple formula takes into account the span of time a person has been smoking as well as the number of cigarettes smoked per day. Smoking 20 cigarettes (a pack) a day for one year is one pack year. Smoking 40 cigarettes a day for one year equals two pack years. The greater the number of pack years, the greater one's risk is for developing lung cancer, chronic obstructive pulmonary disease, and all other smoking-related illnesses. To calculate your pack years, multiply the number of years you have smoked with your best estimate of how many cigarettes per day you have smoked, and divide that number by 20—the number of cigarettes in a pack:

15 years of smoking X 40 cigarettes per day/ 20 = 600/20 = 30 pack years. LESS

PART 3 The Rewards of Nicotine

It Adds Up

Number of adult smokers in the U.S.

Let's face it: If there were no positive outcomes to smoking, no one would ever do it. “There are many motivations to smoke,” says Michael D. Stein, M.D., Professor of Medicine and Community Health at Brown University and author of The Lonely Patient and The Addict. “The dominant one is physical dependence-that is, smokers who try to stop have withdrawal symptoms, and cigarettes relieve the symptoms. But nicotine can also improve attention and vigilance. Smokers smoke when they need to concentrate or focus. Smoking helps some people feel in a better mood, or they feel a high, a buzz. Some smokers enjoy the taste and smell of a cigarette. Finally, smoking serves as an appetite suppressant. People smoke to control their weight.” While all medical experts agree that the health risks are not worth these beneficial aspects, many smokers have a real fear of losing the sense of control and other pleasurable sensations when they stop.