December 4, 2012
Gene Plays A Role In Binge Drinking In Young Teenagers
Lawrence LeBlond for redOrbit.com - Your Universe Online
It´s an undeniable fact that many teenagers are going to experiment with alcohol before they are mentally ready enough to do so. Now, a new study may help explain why some of these teenagers are more prone to continue drinking alcohol after trying it than others are.
Publishing their work in the journal Proceedings of the National Academy of Sciences (PNAS), the team found that animals lacking the gene had far less desire for alcohol than those who did have it. Adding to that finding, brain scans of 663 teenage boys showed that those with the human version of the gene had heightened dopamine responses in tests.
Alcohol, as well as some addictive drugs, activates the dopamine system in the brain which is responsible for feelings of pleasure and reward. Recent studies on RASGRF-2 in mice showed that the gene is a risk factor for alcohol abuse; yet, the exact mechanism involved in the process has remained a mystery until now.
During a task designed to make the test subjects anticipate a reward, the 14-year-old boys had more activity in an area of the brain called the ventral striatum, an area known to be involved with dopamine release. When the boys were contacted again at age 16 and asked about their drinking habits, the team found the boys with the RASGRF-2 variation drank more frequently than those who didn´t have the gene.
Lead researcher Professor Gunter Schuman acknowledged that his team´s findings do not necessarily prove that the gene variation causes binge drinking, but noted a variety of environmental factors along with several genes could be the right ingredients to contribute to the issue. He does believe, however, that his team´s findings help shed light on why some people appear to be vulnerable to the allure of alcohol.
Schuman said the gene appears to regulate “how rewarding alcohol is for some people.”
"People seek out situations which fulfill their sense of reward and make them happy, so if your brain is wired to find alcohol rewarding, you will seek it out. We now understand the chain of action: how our genes shape this function in our brains and how that, in turn, leads to human behavior,” he said in a statement.
“We found that the RASGRF-2 gene plays a crucial role in controlling how alcohol stimulates the brain to release dopamine, and hence trigger the feeling of reward. So, if people have a genetic variation of the RASGRF-2 gene, alcohol gives them a stronger sense of reward, making them more likely to be heavy drinkers,” Schuman continued.
According to background information in the study, about 6 out of 10 teens aged 11-15 in England report drinking, a figure that has remained stable for more than 20 years. However, binge drinking has become more common, with teens reportedly drinking an average of 6 units per week in 1994 and 13 per week in 2007. In the UK, nearly 5,000 teens are admitted to the ER each year due to alcohol use.
Schuman said more research was needed to prove whether or not the gene variation is directly linked to increased use of alcohol. He said the study only looked at young teenage boys, making it difficult to assess a link with long-term drinking patterns.
In the future it may be possible to offer gene tests to help predict which people are more at risk of alcohol abuse. He added that his team´s findings may also provide a way to produce drugs capable of blocking the “reward effect” in people with the gene variation.
"Anything that adds to our understanding is useful,” Dr. Dominique Florin, of the Medical Council on Alcohol, told the BBC. "It's likely that there is a genetic component to problem drinking, but that's not to say that if you have this gene you should never touch alcohol or if you don't have the gene then it will be fine for you to drink."
“Identifying risk factors for early alcohol abuse is important in designing prevention and treatment interventions for alcohol addiction,” concluded Schuman.