New genetic research into nicotine addiction shows promise for personalized treatmentSeptember 18, 2007Whether a smoking-cessation drug will enable you to quit smoking may depend on your genes, according to new genotyping research from the Centre for Addiction and Mental Health (CAMH). The study, published in the September issue of the journal Biological Psychiatry, found that the enzyme known to metabolize both the smoking cessation drug bupropion and nicotine is highly genetically variable in all ethnicities and influences smoking cessation. This finding is a step toward being able to tailor smoking cessation treatment to individuals based on their unique genetic make-up. "This first study identifies a very common genetic variant (present in anywhere from 25 to 50 percent of world populations) that appears to affect the outcome of smoking cessation treatment," said Rachel Tyndale, Section Head of Pharmacogenetics at CAMH and lead researcher on the study, adding that the results would have to be replicated. Tyndale and colleagues performed genotyping on smokers for CYP2B6, a gene known to be highly variable and whose enzyme metabolizes bupropion, nicotine and serotonin. Participants were then provided with either placebo or bupropion treatment for ten weeks and followed up for 6 months.
The research project, supported by the Canadian Institutes of Health Research and the National Institute of Health, found that 45% of individuals with a specific variant of the gene benefited from bupropion treatment and maintained abstinence longer while doing poorly on placebo, with a 32.5% abstinent rate vs. 14.3%, respectively. In contrast, the 55% with a different variant of the gene (wild type variant) had good abstinences rates on placebo and gained no additional benefit from Bupropion, suggesting no benefit from treating these individuals with Bupropion. Of note, this group was able to quit smoking very well in the absence of an active drug (on placebo). What percentage of people fall into the group that appeared to benefit" Previous studies have shown that 45%, 50% and 25% of White, African and Asian North Americans have the former specific variant form of the CYP2B6 gene. The current study looked only at people of European ancestry, says Dr. Tyndale, but she and her colleagues have begun a similar study in African American smokers. They hypothesize that the variant form of the CYP2B6 gene will influence the effectiveness of bupropion treatment and ability to quit smoking in the same way in African Americans as in those of European descent. Centre for Addiction and Mental Health | |||||||||||||||||||||
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Related Nicotine Addiction Current Events and Nicotine Addiction News Articles ADHD appears to increase level of nicotine dependence in smokers Young people with ADHD are not only at increased risk of starting to smoke cigarettes, they also tend to become more seriously addicted to tobacco and more vulnerable to environmental factors such as having friends or parents who smoke, according to a study from Massachusetts General Hospital reseachers. Caltech scientists engineer supersensitive receptor, gain better understanding of dopamine system Genetically modifying a receptor found on the neurons that produce the neurotransmitter dopamine has given California Institute of Technology (Caltech) researchers a unique glimpse into the workings of the brain's dopamine system--as well as a new target for treating diseases that result from either too much or too little of this critical neurotransmitter. K-State professor's research suggests that cigarettes' power may not be in nicotine itself There may be a very good reason why coffee and cigarettes often seem to go hand in hand. If your first cigarette gave you a buzz and you now smoke, a gene may be to blame Anyone who has ever tried smoking probably remembers that first cigarette vividly. For some, it brought a wave of nausea or a nasty coughing fit. For others, those first puffs also came with a rush of pleasure or "buzz." Research reveals why some smokers become addicted with their first cigarette New research from The University of Western Ontario reveals how the brain processes the 'rewarding' and addictive properties of nicotine, providing a better understanding of why some people seemingly become hooked with their first smoke. Understanding teen attitudes critical to quit message Teen attitudes to smoking need to be re-examined if anti-smoking health campaigns are to be effective, according to Hunter researchers. New studies on cancer and schizophrenia, depression and heart disease, trauma and autism The 2007 American College of Neuropsychopharmacology Annual Meeting will feature hundreds of new studies on brain and behavior from the world's leading scientists. Presentations include innovative research on potential new treatments for depression, post-traumatic stress disorder, autism and addiction. Study suggests nicotine addiction might be controlled by influencing brain mechanisms There is a clear link between GABA - a chemical substance of the central nervous system that inhibits neurons in the brain - and nicotine dependence, according to a study presented today at the American College of Neuropsychopharmacology (ACNP) annual meeting. Survey identifies characteristics of teens who smoke marijuana but not tobacco A Swiss study suggests that teens who use only cannabis appear to function better than those who also use tobacco, and are more socially driven and have no more psychosocial problems than those who abstain from both substances. Scripps research study reveals mechanism behind nicotine dependency The new study reveals that, in rats, chronic nicotine use recruits a major brain stress system, the extrahypothalamic corticotropin releasing factor (CRF) system, which contributes to continued tobacco use by exacerbating anxiety and craving upon withdrawal. The researchers found that administering a compound that blocked the receptors involved in this stress system alleviated withdrawal symptoms. More Nicotine Addiction Current Events and Nicotine Addiction News Articles |
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