Drinking histories were obtained from each participant by trained research staff as part of the regular MLS assessment schedule. Beginning at age 6 and occurring at three-year intervals, a health and daily living questionnaire was used to assess the use of alcohol (more than a sip) and, if applicable, the age at which use occurred and the quantity/frequency of use. Beginning at age 9 and occurring at three-year intervals, the child version of the Diagnostic Interview Schedule for the DSM-IV (DISC; Shaffer, Fisher, Lucas, Dulcan, & Schwab-Stone, 2000) (and beginning at age 18, the adult version [DIS-IV; Robins et al., 2000]) was used to make diagnoses of alcohol abuse and dependence based on DSM-IV criteria. Finally, at annual assessments beginning at age 11, the Drinking and Drug History Questionnaire (DDH; Zucker & Fitzgerald, 1994) was used to assess the quantity and frequency of alcohol use as well as the number of times each of 27 alcohol-related problems occurred (see Supplemental Material for examples). From these assessments, the following alcohol outcomes were calculated by dividing the respective cumulative totals by the
