schizophrenia or the report of physical problems that precluded alcohol challenges. The original protocol was limited to males to optimize the rate of expression of AUDs over time, and to Caucasians because few African-Americans attended UCSD and 40% of Asians had alcohol-related flushing that could affect their LR measures. The requirement that probands did not have a SUD or AUD excluded individuals with early onset substance-related disorders that often reflect preexisting severe conduct or antisocial problems (Schuckit, 2009; Slutske et al., 2002). Individuals were selected as matched pairs of sons of alcohol dependent fathers and FH-negative controls who were similar on demography as well as alcohol and drug use histories. By T1, 64% of these probands had some experience with illicit substances.
