Compelling Evidence for Genetic Influence on Drinking Behavior
Both gene mutations are widespread in the population, one person in five or one person in ten carry this mutation in their genotype.
”Interestingly, both CRHR1 mutations affect only a very specific aspect of our drinking behavior,“ explained Gunter Schumann, professor at the Institute of Psychiatry at King’ s College London and at the Central Institute of Mental Health in Mannheim. Together with his team he studied 600 alcohol-dependent people with varied drinking behaviors. Of this group, almost 300 were adolescents who had had their first experiences with alcohol at the age of 13 years.
The CRHR1 gene provides the blueprint for a protein that plays a key role in dealing with stress and is important in controlling feelings. Does this mean that there is a relationship between stress management and drinking behavior?
”We were able to show that mice with a defective CRHR1 gene drink significantly more alcohol in stress situations than normal mice,“ explained Professor Rainer Spanagel, who as scientist in the National Genome Research Network is also researching the causes of alcohol dependence. “For human beings, it is probably the same. When we are no longer able to fight against stress, we drink more alcohol.“
There are indications that besides the CRHR1 mutations there are additional genes which, together with external factors, influence drinking behavior. “Alcohol addiction is inherited to 50 to 60 percent,“ according to Schumann. Studies of children whose biological parents were alcoholics but who grew up in foster families without alcohol abuse confirm this. Schumann: “The risk that these children will become alcoholics is three to four times higher.“
The scientists hope it will soon be possible to help at-risk persons before they become alcoholics. Knowing the genetic causes of the addiction may facilitate the development of individualized drug treatments for alcoholics.
