stratification at the OPRM1 locus. Inclusion criteria for the study were: (1) ages between 21 and 55, (2) met DSM-IV criteria for current alcohol dependence, (3) no serious medical illness, use of psychotropic medications, history of psychotic disorders, bipolar disorder, or suicidal ideation, (4) no current drug use (other than tobacco and marijuana), verified by a toxicology screen, (5) and no DSM-IV drug abuse or dependence in the past 12 months. Participants had a blood alcohol concentration (BAC) of 0.00 g/dl prior to scanning.
