A genetic variant present in nearly half of Americans of European ancestry is linked to greater effectiveness of the smoking cessation medication bupropion (Zyban), according to a study in the September issue of Biological Psychiatry.

In a study co-led by Rachel F. Tyndale, MD, PhD, Center for Addiction and Mental Health at the University of Toronto, and Caryn Lerman, PhD, Transdisciplinary Tobacco Use Research Center at the University of Pennsylvania, Philadelphia, more than 300 smokers were given either bupropion or a placebo for 10 weeks.

"After 10 weeks of treatment, participants with [CYP2B6 gene] variant had significantly better quit rates on bupropion than on placebo, whereas those without it did equally well on both placebo and bupropion," says Tyndale. "Additionally, among all participants who took bupropion, those with this variant were less likely than those without it to have resumed smoking at the six month follow-up."

Previous studies have shown that about 45% of Americans of European ancestry have this variant form of the CYP2B6 gene. This variant is also found in about 50% of African Americans and 25% of Asian Americans. The current study looked only at people of European ancestry, but the researchers predict similar results for African American smokers with the variant.

Scientists hope that the findings can be used to create more target-specific and individually tailored medications.

To read the full press release, click here.