Researchers have discovered a new genetic link between impulsivity and teenage binge-drinking, which may pave the way for tackling other disorders such as drug addiction and ADHD
An international team from the UK, Germany, Ireland, USA, France and Canada studied mice in order to identify candidate genes associated with a specific form of impulsivity – a reduced ability to wait to respond to obtain a reward, resulting in loss of the reward. Their findings were cross-referenced with an international database of genetic information, which enabled them to narrow down the search for genes that might have a role to play in human impulsivity.
The study then looked at potential associations of these candidate genes with a related measure of impulsivity, as well as with risk taking and alcohol use in human adolescence. They did this by asking some of the 1,423 adolescents assessed as part of the IMAGEN project, which is investigating mental health and risk-taking behaviours in teenagers, to undertake an impulsivity test while undergoing fMRI scans. The results were then checked against their DNA profiles to see if the same genes identified in the mice were associated with their impulsivity scores.
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. Variations in one gene in particular – KALRN – were associated with both impulsivity and with a tendency to binge drink.
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 behaviour 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 behaviour like binge-drinking.
We have identified a variant of a specific gene, called KALRN, which is seen in teenagers who act impulsively and also binge-drink. This link is interesting as it suggests that people can be predisposed to impulsive behaviour, and perhaps also to early life alcohol abuse. If we can understand how these gene variations predispose people to impulsive behaviour, we may be able to help control binge-drinking and other disorders linked to impulsivity, like drug addiction and ADHD.
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.