University of Michigan investigators discovered variations in a particular gene can contribute to the risk of alcoholism by influencing impulsivity.
Practically, the genetic variation may cause individuals who are in distress to act impulsively, a behavior that may lead to the development of alcohol problems, said lead author Sandra Villafuerte, Ph.D.
“Developing deeper understandings of the various genetic and environmental factors involved in risky behaviors may guide prevention and treatment efforts in the future,” Villafuerte said.
The study included 449 people, who came from 173 families, 129 of whom had at least one member diagnosed with alcohol dependence or abuse.
Those with certain variations in the GABRA2 gene were more likely to have alcohol dependence symptoms and higher measures of impulsiveness in response to distress, the study found. Stronger associations were found in women than in men.
The finding corresponds to the belief that men and women tend to have different pathways to alcoholism. Drinking to relieve anxiety and distress is seen more in women, according to the researchers.
In a related study, functional magnetic resonance imaging (fMRI) was used to observe changes of blood flow in the brains of 44 young adults from these families as they performed a task in which they anticipated winning or losing money.
“The neuroimaging allowed us to see for the first time how these genetic variants create differences in how the brain responds in certain situations,” said Mary M. Heitzeg, Ph.D.
In this investigation, researchers determined that individuals with one form of the GABRA2 gene associated with alcoholism displayed significantly higher activation in the part of the brain called the insula.
The insula’s association with addictive behavior is well known: Smokers who had insula damage due to stroke found it much easier to give up cigarettes, Science reported in 2007.
“We believe these results suggest GABRA2 exerts an influence on an underlying neural system that impacts early risk factors and, later, alcohol dependency,” said the researchers. “In the future, we hope to further examine the effects of family environment and other behavioral and environmental factors.”
The authors stress that genetic risk factors don’t act alone and simply having them does not mean that someone will become an alcoholic.
The results are published online in the journal Molecular Psychiatry.
Source: University of Michigan