The diagnostic interview assessment was modified from the SSAGA (30,31) for telephone administration, with deletion of certain diagnostic sections and elimination of non-DSM items. Assessment of history of alcohol abuse and dependence was supplemented with detailed questions about alcohol consumption (frequency of use, frequency of heavy drinking [using 5 or more drinks in a day], frequency of drinking to intoxication, drinks per typical drinking day). These were coded categorically, with 10 response categories and a wide range of values (e.g. 1–2 to 31 or more drinks in a typical drinking day) used to encourage more accurate reports; and were asked of both heaviest drinking period of at least 12 months duration, and of past 12 months (if not included as the heaviest period). Two additional open-ended items coded maximum drinks (“Max Drinks”) in a 24-hour period, lifetime and in the past 12 months. All questions used standard Australian drinks [=10g of alcohol]. Diagnostic sections on smoking, anxiety, depression and conduct disorder were included based on their relevance for understanding alcoholism genetics. Given the potential for inaccurate reporting by interviewed parents
