Doctors should be using these tools to help their patients give up cigarettes, a surgeon general's report due out this summer will advise. Treating nicotine addiction as a medical problem not only recognizes that many smokers need help to quit but also removes the sense that relapse reflects failure. And, as with high blood pressure, if doctors and patients stick with it, effective treatments can be found. They become dependent on its ability to deliver the benefits every time they smoke. The drug works through the same pathways in the brain as other chemicals of addiction, increasing levels of dopamine, a brain chemical responsible for feelings of pleasure.
Genes play a role, too, making some people more likely to become addicted.
The flip side of nicotine's pleasurable effects is the misery experienced by many smokers who try to quit. Long-term exposure to nicotine causes the number of nicotine receptors in the brain to increase. This boosts the body's demand for the drug, according to Jack Henningfield, former head of clinical pharmacology at the National Institute on Drug Abuse. These hungry receptors lead to irritability, depression, and anxiety when the brain is deprived of nicotine. Nicotine-replacement products, which provide much smaller doses of the drug in gum, skin patches, nasal sprays, or inhalers, help smokers wean themselves from cigarettes.