Tobacco Dependence and Health

According to the Centers for Disease Control and Prevention, about 43.4 million adults in the U.S. currently smoke. Men are more likely to smoke (22.3 percent of men) than women (17.4 percent are smokers).

Tobacco smoke contains more than 4,000 chemicals, at least 250 of which are known to be harmful. 50 of the chemicals in tobacco smoke have been linked to cancer. These harmful chemicals put smokers at higher risk for a number of health problems, compared to nonsmokers. Smoking is believed to be the cause of 90 percent of all lung cancer deaths in men and 80 percent of the deaths in women. Smoking is also associated with an increased risk for cancers of the esophagus, mouth, throat, voice box, kidneys, cervix, bladder, pancreas, and stomach. In addition, smokers are at higher risk for other types of lung diseases (like emphysema, bronchitis and pneumonia), heart disease and stroke. The CDC reports both smoking and non-smokers’ exposure to second-hand smoke cause about 443,000 deaths each year in the U.S.

Quitting Smoking

The CDC reports that about 70 percent of smokers say they want to quit. In fact, 40 percent of smokers try to kick the habit every year. But it’s not easy. Nicotine has been called the most common form of chemical dependence in the U.S. Within seconds of the first puff of the cigarette, high levels of nicotine reach the brain. Like any addictive drug, nicotine causes a variety of withdrawal symptoms when a smoker doesn’t get his/her “fix.” Some of the most common signs of nicotine withdrawal include: anxiety, irritability, depression, problems with concentration, difficulty sleeping, fatigue and increased appetite.

There are several different types of aids that are available to help smokers kick the habit. Nicotine replacement is available in the form of a patch, gum, lozenge, nasal spray or inhaler. Two medications are also approved as stop-smoking aids. Bupropion (Zyban®) is an antidepressant that may reduce nicotine withdrawal symptoms and thus, limit the urge to smoke. Varenicline (Chantix™) is a newer stop-smoking medication that works in two ways: it eases withdrawal symptoms and blocks the effects of nicotine if patients start smoking again. Medications are often combined with some type of nicotine replacement and counseling or behavioral therapy.

Finding the Best Stop Smoking Therapy: QuitRx

Jennifer Minnix, Ph.D., Researcher at M.D. Anderson Cancer Center in Houston, says the standard smoking cessation therapies don’t work for everyone. Some people respond better to one type of therapy than another. The QuitRX study is designed to help doctors understand how the brain responds to negative emotions in patients using smoking cessation therapy.

About 400 people will be enrolled in the QuitRx study. Participants are randomly assigned to one of three treatment groups: bupropion, varenicline or a placebo. In addition, all participants will have access to a counselor during the study period.

Participants will come back for an assessment seven times over a ten-week period. At each visit they will answer questions about mood, cravings and other withdrawal symptoms. Researchers will also keep track of how many people actually quit during the study period. Follow-up visits will be done three months and six months after stopping the medication or placebo. Brainwave measurements will be taken to look at brain function and emotional health (based on brain wave activity).

The investigators are hoping the data from the study will provide clues about how different types of smoking cessation treatments work. That information may eventually enable doctors to provide customized smoking cessation programs that help a smoker to quit and remain tobacco-free permanently. Minnix points out that so far, counseling has been shown to have the greatest impact on the ability to stop smoking permanently.

For help on quitting smoking, go to

Smoke Free

or call (800) QUIT-NOW.

For general information on smoking and smoking cessation:

American Cancer Society

Centers for Disease Control and Prevention

National Cancer Institute