14 DAY TRIAL // A new research carried out at the Behavioral Science Institute in The Netherlands, found out that people possessing a version of the DRD4 gene were more likely to drink more if people around them did so.
Why some people adapt their drinking behavior to that of others around them was a mystery scientists tried to uncover for some time now. A recent study shows that the culprit for this behavior is the dopamine D4 receptor, or DRD4. This gene that has previously been associated with dependence on feel-good rewards brought by drugs or chocolate, and with novelty-seeking behavior is also influencing some people's sensitivity to alcohol consumption.
To experiment this theory, researchers installed a bar in a university laboratory. They pretended a commercial rating study and had participants watching and classifying television ads. Then they told them to have a break and that they could do so at the bar, along with their partners. Only that participants' partners were working with the researchers and they were given instructions of how much to drink while sitting at the bar. Once the experiment was launched, all scientists had to do was observed the participants' behavior.
The result of the genetic analysis proved that students that imitated the most their partner's drinking behavior, had a version of the DRD4 gene, called the 7-repeat allele. The study was published in the July issue of Psychological Science.
This version of the gene was already involved in several addictive behaviors that included nicotin, alcohol, heroin use and overeating, by previous studies. In 2007, a study carried out by scientists at the Central Institute of Mental Health in Germany followed 300 teenagers to gather data about alcohol consumption and personality traits. The survey genotyped adolescents' DNA: those who had the 7-repeat allele typically drank more in a given occasion.
Another study published in 2008 in Pharmacogenomics by researchers at Brown Medical School in Rhode Island, concluded that having a copy of this gene variant made quitting smoking more difficult and increased the risk of recidivating.
Helle Larsen, co-author of the study said that even if the current study on drinking behavior was “among students and not alcoholics, it could indeed mean that it is harder for recovering alcoholics that are carriers of the 7-repeat allele to refrain from drinking when exposed to alcohol cues.” She added that men and women are equally likely to possess the 7-repeat allele.
The explanation for this gene variant might be found 40,000 to 50,000 years ago, when it became necessary as a survival mechanism. It could have helped our ancestors take risks to find shelter, food and mates, concluded a 2008 study by Harvard University researchers published in the journal Evolution and Human Behavior, relates LiveScience.
If researchers understood the functioning of the allele in the 21st century, they would probably be able to better treat addictive behaviors.