The same gene variations that make it difficult to stop smoking also increase the likelihood that heavy smokers will respond to nicotine-replacement therapy and drugs that thwart cravings, a new study shows.
The findings of the study, led by investigators at the Washington University School of Medicine, suggest it may one day be possible to predict which patients are most likely to benefit from drug treatments for nicotine addiction (American Journal of Psychiatry, May 30, 2012).
"Smokers whose genetic makeup puts them at the greatest risk for heavy smoking, nicotine addiction, and problems kicking the habit also appear to be the same people who respond most robustly to pharmacologic therapy for smoking cessation," said senior investigator Laura Jean Bierut, MD, a professor of psychiatry, in a university press release. "Our research suggests that a person's genetic makeup can help us better predict who is most likely to respond to drug therapy so we can make sure those individuals are treated with medication in addition to counseling or other interventions."
Dr. Bierut and colleagues analyzed data from more than 5,000 smokers who participated in community-based studies and more than 1,000 smokers in a clinical treatment study. The scientists focused on the relationship between their ability to quit smoking successfully and genetic variations that have been associated with risk for heavy smoking and nicotine dependence.
They found that people with the high-risk genetic markers smoked an average of two years longer than those without these high-risk genes, and they were less likely to quit smoking without medication. In addition, individuals with the high-risk variants were three times more likely to respond to drug therapy, such as nicotine gum, nicotine patches, the antidepressant buproprion, and other drugs used to help people quit.
