Friday, April 15, 2005

New Study Reveals Genetic Component to Nicotine Addiction

A study published in the current issue of Behavioral Neuroscience reports that researchers have identified genetic factors that may relate to susceptibility to nicotine addiction. According to the American Psychological Association press release on this article, "Understanding how genes change nicotine receptors may foster better treatments." Senior author, Dr. Jerry A. Stitzel from the University of Colorado, stated that: “By identifying genes that contribute to whether an individual will become addicted, we will gain important knowledge about the biology of addiction. With that, we will be in a much better position to design more effective treatments for addiction. This approach may also lead to treatments tailored to the ‘genetic profile’ of the smoker.”

This study is not the only one examining potential genetic factors in nicotine addiction. New Zealand researchers are apparently studying gene variants that may influence nicotine metabolism (and therefore addiction). They are apparently testing individuals for these genetic variants and have claimed that "Genetic tests based on this could enable personalised nicotine replacement therapy to be developed, making it more likely that it will be successful." Similar studies are ongoing elsewhere.

The Rest of the Story

While I'm all for tobacco research, I really don't see much value in this line of inquiry. Let's stipulate, for the purposes of argument, that there is indeed a very strong genetic influence on nicotine addiction. OK, so what should we be doing differently?

The research doesn't seem to have any useful implications for efforts to prevent smoking. Even if we were able to identify precisely those kids who are most at risk for becoming addicted, would we deliver our interventions only to those kids? There are so many factors, both genetic and environmental, that influence smoking initiation, that our interventions to prevent smoking will always have to be broad-based and targeted at a large segment of the (if not the entire) youth population. And I can't see doing genetic testing on kids to determine which ones will receive certain interventions. Most importantly, the interventions that have been found to be most effective in preventing smoking are societal-level, population-based interventions, not individually delivered ones.

Could the research have important implications for smoking cessation interventions? Again, the most successful interventions we have to encourage smoking cessation are population-based (such as aggressive marketing campaigns and smoke-free laws). It's not clear to me how even an individual-level intervention, such as nicotine replacement therapy, would be altered based on a genetic test to make a substantial difference in the effort to help smokers overcome their addiction. What is it that we can't already measure? For example, we already have ways of determining the strength of someone's addiction to nicotine. Usually, it's quite readily apparent. In fact, usually the smoker herself knows exactly what the strength of cessation difficulty is. I don't think there's anything that you couldn't ascertain from a simple, inexpensive, and carefully conducted interview with a smoker that you could ascertain from a fancy and expensive DNA test.

In short, I don't see any substantial value in this line of research into genetic susceptibility to nicotine addiction. It has no important implications for the practice of tobacco control, either for the prevention of smoking or the encouragement of smoking cessation. It does not seem to provide any essential information that we cannot already obtain if we are careful enough and take enough time to talk to our patients. It may be detracting from and/or reducing funds available for research that really does have important implications for public health policy and practice. And it may even help the tobacco industry in its litigation by allowing the companies to argue that genetic susceptibility, not corporate behavior, is the most salient factor in nicotine addiction (although that's not a reason to fail to conduct this research if it were otherwise important).

We really already have a very good idea of what works and what does not work in tobacco control. I think it's time that we start putting our money into implementing these proven strategies, rather than just doing more basic research to find out fancier and more expensive ways of ascertaining information that we can already find out, if we only are willing to take the time to talk to the affected individuals.

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