What Triggers Alcoholism?

January 01, 2013

According to the Centers for Disease Control and Prevention, excessive alcohol use accounts for 80,000 deaths each year in the United States, making alcoholism the third leading cause of preventable death behind obesity and smoking. In an effort to uncover the connection between genetic influences and environmental factors that may cause alcoholism, Assistant Professor of Statistics Tatiyana Apanasovich is employing statistical methodology to explore the complex interplay between the an individual’s environment and their genetic predisposition to alcoholism. The National Institutes of Health (NIH) awarded her a two-year, $146,000 grant to develop this methodology and a user-friendly software package to accompany it.

 “Statistics provides tools by which scientists can better understand complex processes,” said Apanasovich, who joined the Department of Statistics in the fall of 2012. “Geneticists have discovered a number of candidate genes that might be associated with susceptibility for alcohol dependence."

Apanasovich noted that 40 to 60% of alcohol dependence is believed to be caused by genetic factors—which influence the biochemistry of reward pathways in the brain—meaning that the remaining 40 to 60% of liability for alcohol dependence lies in environmental factors that encourage alcohol consumption and their interaction with genetic factors.

“To model an individual’s risk of alcohol addiction, I am considering genetics and environment together in the same study,” explained Apanasovich. “An individual’s genetic information is measured by hundreds of thousands of genetic variants. Most environmental factors are measured using self-reported information, which is inevitably subject to all sorts of imperfections.”

In this study, Apanasovich is focusing her research efforts on the development of advanced statistical and computationally efficient methodologies. The methodologies she develops for risk of alcoholism can be applied to other complex diseases as well.

Using data on 4,000 patients collected from a nationwide NIH study, Apanasovich is taking a new approach to gene-environment association studies by attempting to model complex effects of environmental exposures to alcohol use and the individual’s genetic predisposition to addictive behavior. The ultimate goal of her work is to find a better way to identify who is the most vulnerable to alcohol addiction, a tremendous step towards more effective prevention and treatment approaches.

“The hereditary risk for alcoholism may be prevented if the individual's environment is good,” said Apanasovich. “Factors such as education level, religion, and marriage can lessen the effects of genetics on risk for alcohol use disorders."

In addition to the NIH grant, Apanasovich has received a $36,500 grant from the GW Food for Thought program to work with Associate Research Professor of Biochemistry and Molecular Biology Anelia Horvath to explore the genomic interplay between obesity and alcohol abuse.

“In recent years, the relationship between overeating and addiction has been explored and some striking similarities have been discovered,” said Apanasovich. “Consequently, it has been hypothesized that alcohol and other drugs can compete with food for brain reward sites, both ultimately providing the experience of pleasure.”

In this project, the researchers hope to find the evidence that overeating and obesity may act as protective factors reducing the risk of alcohol addiction in genetically vulnerable groups. They hypothesize that those with a predisposition to alcoholism may focus their addictive tendencies on foods high in sugar, salt, and fat instead of on alcohol.

Applying statistical methodologies, the researchers will search for molecular pathways in the brain involved in development of food and alcohol abuse behaviors. Such findings would add more genetic evidence to food addiction theory and would ultimately suggest that both addiction and obesity researchers could help each other develop useful treatments.

“Both obesity and alcohol abuse cluster in families and are highly inheritable,” said Apanasovich. “We hope to provide means for better understanding of what causes addictive behaviors in food and alcohol consumption. An individual’s genetic susceptibility should not be treated as destiny, but rather as an opportunity to implement a lifestyle plan to avoid individual risk factors and live up to one’s genetic potential.”