[Genetic control of the ethanol effect on the human EEG].

26 identical and 26 fraternal twin pairs were subjected to 1,2 ml/kg alcohol loading under standardized conditions; furthermore, 13 non-twin persons were repeatedly subjected to the same procedure in order to test the intraindividual variability. The alcohol effect was pursued by repeated EEG recordings. The EEGs of identical twins proved to react identically to alcohol loading, whereas the EEGs of fraternal twins became more dissimilar during the course of the experiment. The identical reaction of the brain wave pattern in monozygotic twins cannot be attributed to more similar blood alcohol concentrations; instead, this finding is a pharmacogenetic phenomenon of the central nervous system.