Researchers from the University of Michigan, Washington University School of Medicine, as well as from the University of North Carolina discovered that the chances of a person to become addicted to smoking could be in his/her genes.

More exactly, they identified a gene variant that is more present in people who become addicted. The same gene variant has been implicated in the development of lung cancer as well, the researchers said in the August 8 issue of the journal Addiction.

“If you have this variant, you are going to like your earliest experiences with smoking. What they don't realize is if they have this kind of genetic make-up, they are on their way to dependency,” Ovide Pomerleau, professor of psychiatry at the University of Michigan Medical School and lead author of the study, said.

The research is the more important as it may help development of anti-smoking drugs. According to current estimates, smoking appears to be the biggest cause of preventable deaths in the US, killing more than 400,000 people annually. Smoking causes nine out of 10 cases of lung cancer, the leading cause of cancer death in men worldwide and the second-leading cause of cancer death among women.

The bad part is that even people who do not actually smoke but live in the presence of smokers are predisposed to serious conditions such as respiratory infections and cancers. Almost 40,000 such people die annually.

For the study, Pomerlau and colleagues analyzed the association between initial smoking experience, current smoking patterns, and a specific variant in a nicotine receptor gene known as CHRNA5 in 435 smokers and nonsmokers.

Nonsmokers in the study had smoked at least one cigarette during their lives but had never become addicted. Smokers had smoked at least five cigarettes a day for the past five years or longer.

The researchers discovered that smokers were eight times more likely to report their first cigarettes gave them a pleasurable buzz compared to nonsmokers. Also smokers were more likely to have the variant of the CHRNA5 gene (rsl16969968) that has been linked with increased susceptibility to nicotine addiction.

“People with this genetic makeup find smoking pleasurable from that first cigarette and they are more likely to get addicted and develop lung cancer,” Pomerleau said.

However, genes alone aren’t responsible for smoking, which is a complex interaction of social and environmental triggers, the researchers said. They are now trying to figure out the way the genetic, behavioral, and environmental components influence smoking and addiction. The findings could lead to the development of new therapies that could help smokers quit the habit much easier than the current treatments for smoking cessation. However, it will take years to develop such a therapy, Pomerleau said.

“Things are moving really fast in this field. We are making new discoveries all the time.”