32 More recently, Whitfield et al analyzed the relationship between blood or breath alcohol values after an alcohol challenge test, a reflection of pharmacokinetics, and risk of alcohol dependence over a 10-year period

of follow-up.33 They observed a two- to threefold increased risk in individuals who demonstrated blood or breath alcohol concentrations in the highest quartile of values Inhibitors,research,lifescience,medical compared with those in the lowest. Genetic variation among alcohol-metabolizing genes has been well studied with respect to their role in affecting predisposition to alcohol dependence.34 A functional variant in aldehyde dehydrogenase type 2 (ALDH2), predominantly observed among Asian populations, produces a reduced capacity to metabolize acetaldehyde and a physiologic flushing response and is believed to contribute to the aversion to alcohol consumption.35 Genetic variants Inhibitors,research,lifescience,medical among the class I alcohol dehydrogenases have also been implicated in modulating levels of alcohol intake.35 These findings suggest that alcohol metabolism does influence susceptibility to alcohol use disorders. Prospective studies have been pursued to evaluate the role of variation in alcohol metabolism on risk of alcohol dependence.13,33

Inhibitors,research,lifescience,medical Overall, there is evidence suggesting that genes that affect alcohol pharmacokinetics are likely to contribute to the levels of alcohol consumption by individuals. Electrophysiological measures Various electrophysiological measures of the brain have been implicated in predisposition to alcohol use disorders. Evidence from twin studies suggests that a substantial Inhibitors,research,lifescience,medical proportion of the variance in electroencephalographic (EEG) patterns is genetically determined.36-39

Studies investigating the EEG of chronic alcoholics have reported the alcoholic EEG to be of lower voltage, to be deficient in a activity, to be higher in p activity, to contain some 9 activity, and to have an excess Inhibitors,research,lifescience,medical of fast activity19,40-44 Studies conducted on offspring of alcoholic fathers suggest that certain EEG variants may be potential endophenotypes for development of alcohol dependence.19,45 A biological trait that has received considerable attention is the P300 waveform, also known as P3, of the eventrelated brain potential (ERP). The P3 waveform represents the largest positive peak voltage of the event-related potential occurring between 250 and Thalidomide 500 ms after presentation of a stimulus.46 This component is believed to depict several aspects of cognitive function, including attention and maintenance of working memory.47 It has been suggested that diminished P3 amplitudes or shorter latencies reflect problems in check details attending and interpreting subtle environmental events.48,49 Research has shown that alcoholic individuals also have reduced P3 amplitude and that offspring of alcoholics with low P3 amplitude are more likely to develop an alcohol use disorder.