*The following is excerpted from an online article posted on PsychCentral.
New research suggests excessive teenage binge-drinking may be influenced, as least in part, by genetics.
Alcohol and drug abuse are major health issues that often begin during adolescence. The teenage years are known to be an impulsive time as emerging adults expand their boundaries. Some teens, however, seem to especially prone to impulsive behaviors leading to binge-drinking.
Researchers at the University of Sussex, working as part of a team of researchers from across Europe, have discovered a new genetic link between impulsivity and teenage binge-drinking.
Their findings appear in the journal Frontiers in Genetics.
Professor Dai Stephens from the School of Psychology at the University of Sussex said:
“Alcohol and drug abuse are well documented as being major public health issues in today’s society. By uncovering a particular gene that links impulsive behavior with binge-drinking we may be an important step closer to understanding why some young people face a struggle to control their urges to engage in risky behavior like binge drinking.”
Investigators identified a variant of a specific gene, called KALRN, which is seen in teenagers who act impulsively and also binge-drink. Researchers believe the link suggests people can be predisposed to impulsive behavior, and perhaps also to early-life alcohol abuse.
Learning how these gene variations predispose people to impulsive behavior, may help professionals intervene to control binge-drinking and other disorders linked to impulsivity, like drug addiction and ADHD, explains Stephens.
Dr Yolanda Peña-Oliver, the postdoctoral researcher who carried out the research under Professor Stephens’ supervision, said: “These results provide an insight into the possible neurobiological and genetic determinants of impulsivity and alcohol abuse. The KALRN gene codes for a protein called Kalirin.
Kalirin is essential to the development of the nervous system, especially the formation of dendritic spines that are important for the ability of nerve cells to communicate with each other. Interestingly, it has also been associated with other impulsivity-related disorders, like ADHD.”
For the study, the researchers already knew that there was a link between impulsivity and a lack of control in drug and alcohol abuse, and that genetic factors contribute to addictions.
Nevertheless, it is scientifically difficult in human studies to identify which particular genes contribute to impulsive behavior and binge-drinking. To gain knowledge on the particular genes involved researchers turned to mice.
Investigators measured how well a known mice genotype was at waiting for a reward – then cross referenced the findings with an international database of genetic information. From this, the team was able to narrow down the search for genes that might have a role to play in human impulsivity.
The study then looked at 1400 teenagers who also took part in a major survey about drinking and drug-taking habits.
The teenagers were asked to respond to cues in order to receive a reward, and underwent fMRI scans as they did so. They were scored for their impulsivity, i.e., their inability to wait for the reward.
When their results were checked against their DNA profiles, the researchers found that many of the same genes they had identified in mice were also associated with the level of impulsivity in the teenagers.
The brain mechanisms contributing to impulsivity in the teenagers were identified by the degree to which one part of the brain, the ventral striatum, was activated while they were waiting for the reward.