As researchers zero in on the genetic root of alcoholism, a new National Institute on Alcohol Abuse and Addiction (NIAAA) study has identified a gene variant that is directly linked to compulsive drinking.
According to the results of a recent animal study, the gene variant affects the release of a specific brain protein that can put a person at greater risk of developing an alcohol use disorder. The National Institute on Alcohol Abuse and Addiction, a division of the National Institutes of Health, funded the study.
Scientists found that mice carrying the gene variant would consume excessive amounts of alcohol. Despite the negative consequences, the presence of the Met68BDNF gene variant, which reduces the release of brain-derived neurotrophic (BDNF) factor, led directly to the abusive behavior. BDNF plays a role in the survival of existing neurons and the growth of new neurons and synapses. In other words, less brain activity removed the inhibition and led to compulsive drinking to the point of negative consequences.
Dr. George Koob, Ph.D., director of the National Institute on Alcohol Abuse and Addiction, underlined the importance of the study. “Genetic factors play a role in determining who develops alcohol problems,” Dr. Koob said. “By understanding the genetic underpinnings of alcohol use disorder, we will be better able to develop targeted treatment and prevention strategies.”
The negative effect of the reduction of the BDNF factor seemed to be specific to alcohol consumption in the mice. Although the lack of the BDNF factor is known to lead to mental illness in human beings, it did not appear to have this effect on the mice except in relation to alcohol consumption. The human form of this gene variant leads to a reduction in the normal function of BDNF in the brain and is associated with several psychiatric disorders, including schizophrenia and depression. The mice, however, did not differ in their consumption of other fluids or exhibit differences in levels of anxiety, compulsive behaviors, depression, or social aggression.
Significantly, by using gene delivery and pharmacology, researchers were able to reverse compulsive alcohol drinking in the mice. By increasing levels of BDNF in the prefrontal cortex, a brain region involved in compulsive drug and alcohol seeking, the researchers noted that the mice returned to moderate levels of alcohol intake. In addition, by administering a pharmaceutical compound developed to mimic the action of BDNF, researchers were also able to put a stop to compulsive drinking behaviors. The NIAAA believes a similar compound may have potential as a therapeutic treatment for humans with binge drinking problems and alcohol use disorders.