Blame your genes if you can't stop smoking cigarettes. Researchers at Duke University Medical Center and the National Institute on Drug Abuse (NIDA) find that the best dose nicotine patch for those quitting smoking depends on differences in genetic variants.
In the trial, 479 cigarette smokers who smoked at least 10 cigarettes per day and wanted to quit were categorized as either high- or low-dependence based on their level of nicotine dependence. The smokers in each group were then randomly assigned to wear two nicotine skin patches daily delivering a high dose ( (42mg) or a standard dose (21 mg). Patches were worn for two weeks prior to their quit date, and the nicotine doses were reduced gradually over the 10 weeks following their quit date. Participants were given denicotinized cigarettes during the two weeks before the quit date to minimize any potential adverse effects from the high dose nicotine patches. The treatment phase lasted for 12 weeks in all.
DNA was extracted from participants' blood and was used to assess a quit-smoking success genetic score.
At six months follow up, the researchers were able to confirm which smokers fared better or worse on the high-dose compared to the low-dose patch.
"The genotype score was part of what predicted successful abstinence. In the future such a score could help us make our initial treatment decisions," said Rose. "People who had both high nicotine dependence and a low or unfavorable quit success genetic score seemed to benefit markedly from the high-dose nicotine patch, while people who had less dependence on nicotine did better on the standard patch."
Genetic differences influence not only the difficulty in kicking an addiction but also the susceptibility to becoming addicted in the first place. For example, Mono Amine Oxidase (MAO) inhibition by tobacco compounds probably enhances addiction and genetic variants in MAO appear to influence risk of addiction.
Humans differ genetically in their capacity to be exposed to addictive drugs without becoming addicted. Keep this in mind the next time you see an addicted person acting destructive toward self and others. Some of those addicted people have genetic variants that make kicking their addiction especially difficult.
|Share |||Randall Parker, 2010 July 05 10:10 PM Brain Addiction|