The major goal of this study was to clarify the degree to which measures of the frequency and quantity of AC reflect the genetic risk for AD as defined in DSM-IV (American Psychiatric Association, 1994). We addressed this question by examining lifetime diagnoses of AD and four measures of AC reported for the period of heaviest lifetime drinking in a large population-based sample of Virginia born twins. The four measures of AC were regular frequency, regular quantity, maximum single day consumption (maximum quantity), and frequency of drinking to intoxication (drunk frequency).
