Smokers' genes may help predict whether they'll respond to drug treatments for nicotine addiction, a new study indicates.
Researchers analyzed data from more than 6,000 smokers in community-based studies and a clinical treatment study and found that the same gene variations that make it difficult to stop smoking also increase the chances that heavy smokers will respond to nicotine-replacement therapy and drugs that reduce the craving for nicotine.
"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," study first author Dr. Li-Shiun Chen, an assistant professor of psychiatry at Washington University of Medicine in St. Louis, said in a university news release.
"The same gene variants can predict a person's response to smoking-cessation medication, and those with the high-risk genes are more likely to respond to the medication," Chen said.
In the clinical treatment study, smokers with the high-risk variants were three times more likely than those without the variants to respond to treatments such as nicotine gum, nicotine patches, the antidepressant bupropion (Wellbutrin is one brand) and other drugs used to help people stop smoking.
The findings, published online May 30 in the American Journal of Psychiatry, suggest it may eventually be possible to analyze smokers' genes in order to predict if they'll benefit from drug treatments for nicotine addiction.
"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," senior investigator Dr. Laura Jean Bierut, a professor of psychiatry, said in the news release.
The gene variants in this study aren't the only ones involved in whether a person smokes, becomes addicted or has difficulty quitting, but they are an important part of the overall nicotine-addiction puzzle, the researchers said.
"These variants make a very modest contribution to the development of nicotine addiction, but they have a much greater effect on the response to treatment," Bierut said. "That's a huge finding."
