Genetics and Addiction

Marc A. Schuckit, MD

Modern medicine has come a long way over the last 100 years in the field of addiction. What was once thought to be a moral disorder and a lack of will power has become recognized as medical disease that can be treated much like any other medical ailment. Addiction is a disease that can arise from heavy use of a substance over an extended period of time or can be passed down genetically from one generation to the next.

New research has shown that genes account for about 60 percent of the risk for addiction, while the environment accounts for the other 40 percent, according to Marc A. Schuckit, MD, distinguished Professor of Psychiatry at the University of California, San Diego. Schuckit is an expert who has developed a pilot program to prevent high-risk drinking in college freshman. He based the first evaluation of a prevention program on his 30 years of research in the field, dealing with more than 400 families.

Dr. Schuckit explained how genes and the environment relate to the risk for alcoholism at the Association for Medical Education and Research in Substance Abuse annual meeting, laying out the risk factors that impact alcoholism. “Genes operate through these risk factors,” he notes. One of the risk factors is a low sensitivity to alcohol. “Some people are a good deal less sensitive to alcohol from the very first time they drink,” Dr. Schuckit says. “They require higher doses of alcohol to get the effect they want.” Low sensitivity to alcohol is seen in groups of people at high risk for alcoholism, including children of alcoholics and Native Americans, he adds. Low sensitivity to alcohol predicts alcoholism and alcohol-related problems, he says.

The low sensitivity to alcohol combined with factors in the environment magnify the risk of alcoholism, some environmental factors are associating with heavy-drinking peers or higher levels of life stress where alcohol is used to help cope with the stress. Dr. Schuckit has identified four genes related to the low response to alcohol.

Schuckit is planning on beginning a much larger, potentially more definitive study in 2013.  

The study results were published earlier this year in Alcoholism: Clinical & Experimental Research.