The data collection protocol was approved by the Human Subjects Protection Committee at the University of California in San Diego and used written, informed consent. The design for the alcohol challenge is fully described in the initial report by Wilhelmsen et al. (2003). Male and female subjects ranging in age from 18 to 29 years old were recruited from a population of college students. Chosen sibling pairs reported having an alcohol dependent parent, but were not alcohol dependent themselves. The siblings included 43.7% males and 56.3% females. They had an average age of 22.4 years and 14.2 years of education. 72.2% were Caucasian, 20.0% were Hispanic, and 7.8% were African-American. For 85.0% of the subjects, the alcohol-dependent parent was the father, whereas for 4.4% it was the mother, in 4.0% it was both parents, and in 6.6% the more intensive interview revealed that neither parent met full criteria for dependence.
