Genetic influences on alcohol consumption and actions of alcohol.

Recent studies, utilizing twin pairs and adoption paradymes, have demonstrated hereditary influences on alcohol drinking behavior and on the risk of alcoholism. It is well recognized that alcoholism is a complex condition involving a number of actions of alcohol and alcohol related behaviors. It is not surprising, therefore, that investigations, in man, have demonstrated individual differences in ethanol metabolism and other actions of alcohol and that these individual differences appear to be genetically influenced as well as influenced by environmental factors. Numerous studies have been conducted over the past decade which demonstrate, in animals, a genetic influence on alcohol metabolism and on the actions of alcohol. In this review, the evidence for a genetic influence on central nervous system sensitivity to the effects of alcohol have been discussed including studies with inbred strains of mice and selectively bred lines of mice and rats. The review summarizes studies which suggest a genetic influence on the acquisition of both acute and chronic tolerance to ethanol and upon the display of withdrawal symptoms following the discontinuance of chronic ethanol exposure. It is clear that heredity has ubiquitous influence on alcohol related processes and that these genetic influences are expressed at the behavioral, pharmacological and neurochemical levels.