Clues looking into the root causes of alcoholism are emerging from new findings that center on the genetic patterns of young drinkers, with particular focus on why adolescents are more likely to drink large quantities of alcohol even if they need more alcohol to get the effects they desire.
"The study offers a unique perspective on the beginnings of the alcohol experience and usage patterns of 12-year-olds," explained principal investigator Marc Schuckit, M.D., professor of psychiatry at the Veterans Affairs San Diego Healthcare System. "This is the first study correlating the intensity of reaction to alcohol with the amount of alcohol consumed at an early age."
Dr. Schuckit, who also is distinguished professor of psychiatry at the University of California, San Diego Medical School, spoke at the American Medical Association media briefing, Alcohol Dependence: From Science to Solutions, held in New York City. He also released his study "Performance of a self-reported measure of the level of response to alcohol in 12- to 13-year-olds" published in the July issue of The Journal of Studies on Alcohol.
In the study, 80 children in Bristol, England, who had some experience with alcohol responded to a questionnaire regarding their drinking habits. On average, the respondents reported drinking alcohol about five times in the previous six months. While most of them only consumed one or two drinks at a time, a significant number reported having four to six drinks at a time.
A low response to alcohol is a risk factor for alcohol dependence and a predictor of future alcoholism. "When children with a family history of alcohol dependence begin drinking, about half of them experience little or no intoxication at blood alcohol levels where others would be feeling moderately tipsy," said Dr. Schuckit. "Consequently, these adolescents have a propensity to drink more heavily when they drink because higher blood alcohol levels are required to produce the effects they want."
For the last 20 years, Dr. Schuckit has been researching the importance of a person's intensity of response to alcohol as one of several inheritable traits that may increase the propensity for alcohol dependence. His research team is searching for genes that may be related to this low alcohol response.
Three primary findings support the importance of genetics and alcoholism. First, the risk for alcohol dependence in the sons and daughters of alcoholics is four times higher than in the general population. Second, the rate of increased risk for alcoholism persists in children of alcoholics even if they are adopted at birth and raised by non-alcoholics. Finally, identical twins have a much higher rate of both becoming dependent on alcohol if one is--compared to the same rate for fraternal twins.