Social drinkers, ages 21 to 27 years, were recruited through local advertisement and then screened by telephone for general eligibility. The sample was limited to European Americans to reduce the potential confounds introduced by SNPs whose allele frequencies differ across racial groups (Cross et al., 2010; Ittiwut et al., 2008). Those who passed the phone screen were invited to the laboratory for a detailed interview which began with a measurement of BrAC to confirm sobriety, followed by acquisition of informed consent approved by the Indiana University School of Medicine Institutional Review Board.
