For some smokers, addiction could be genetic

Ever wondered why some people gag on their first-ever cigarette, while others are instantly hooked? Some people, it seems, are genetically predisposed to develop a smoking addiction after just one smoke. Manipulating such responses could help wean smokers off the habit—and prevent would-be smokers from starting at all.

Nicotine causes either positive or negative effects as it hits dopamine receptors in the brain, says Dr. Steven Laviolette, an assistant professor at the University of Western Ontario. Yet it seems these reactions can actually be controlled. In a new study (published Aug. 6 in The Journal of Neuroscience), Laviolette’s research team targeted specific dopamine receptors that control one’s initial sensitivity to the addictive properties of nicotine. “When we pharmacologically blocked those receptors, we could take a dose of nicotine that was normally unpleasant, and switch it into a rewarding stimulus,” and vice versa, he says.

Laviolette’s research, which was performed on rats, could have huge implications for combating smoking: “If we could develop genetic screens to determine increased vulnerability” to nicotine addiction, we might know who’s at risk of getting hooked, he says. And because these particular dopamine receptors are also involved in mediating the unpleasant effects of nicotine withdrawal, targeting them with drugs could help those who are already addicted. “If you prevent withdrawal, you hopefully prevent relapse,” he notes.

This could have implications for other types of addiction as well. From alcohol to cocaine, “pretty much anything you can imagine interacts with this particular neurochemical pathway,” he says. “Hopefully the implications are translatable.”

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