Why Do Some People Drink Too Much?

17 A lcohol is available to any adult, and illegally to many minors, in the United States. Although most people abstain or drink safely, a sizable minority of the population abuses alcohol. Understanding why alcohol leads to trouble for many, but not most, people exposed to it is the goal of re s e a rc h on the cause (i.e., etiology) of alcohol abuse and alcoholism. It is already clear that some vulnerability to deve l o p i n g a l c o h o l related problems is conve ye d g e n e t i c a l l y, and animal re s e a rch has indicated that inheritance can take many forms. Studies in mice have demonstrated that various individual genes or g roups of genes can shape ve ry distinct responses to alcohol, such as a pre f e re n c e for alcohol over water, sensitivity to a l c o h o l’s intoxicating effects, and the tendency to develop tolerance to it. By identifying the proteins these genes encode and the mechanisms by which the genes influence an animal’s biochemical response to alcohol, scientists can gain insight into the features of human alcoholism and provide a basis for d e veloping pharmaceuticals that short c i rcuit these genetically defined pro c e s s e s . Another goal of re s e a rch on the genetics of alcoholism in humans is to determine to what extent individual d i f f e rences in alcohol-related behavior a re due to genetic versus enviro n m e n t a l influences. For example, in twin studies as much as two-thirds of the va r i a b i l i t y in drinking behavior in one population could be attributed to genetic factors in both men and women. Other twin studi e s a re investigating the re l a t i ve magnitude of various influences on alcohol consumption in youth. Identifying the genes that convey risk of alcoholism is a second major goal of genetic re s e a rc h ; scans of the human genome re veal evidence of genes in certain chro m o s o m a l regions that influence alcoholism. Understanding how inborn vulnerability plays out in the temperament and behavior of an individual and in the context of family, peers, and culture is the goal of psychosocial re s e a rch on the cause of alcoholism. The traits and family characteristics of children at risk because of a family history of alcoholism also predict risk in children of nonalcoholic parents. If alcoholism re p re s e n t s the end result of a sequence to which many factors contributed, then the hope is that by understanding the contributors and how they interact, it also will be possible to intervene before vulnerability becomes a destru c t i ve illness.