A Caucasian-only subset of sample comprising 209 families and 1049 individuals was used in the genetic association analysis (containing 472 individuals diagnosed as alcohol dependent by DSM-IV). Details of the demography of the subjects included in this study were reported in our recent study (Chen et al., 2009) and summarized in Table 1. Briefly, between alcoholic and unaffected groups, there was no significant difference in age (unaffected: 39.30 ± 0.55, mean ± SEM, ranging from 18.09 to 70.41 years old; alcohol dependence: 39.60 ± 0.61, ranging from 17.94 to 73.38), common co-occurring psychiatric disorders, e.g., antisocial personality disorder, major depression, bipolar disorder, obsessive compulsive disorder (Schizophrenia is an exclusion in recruitment.), and other substance dependence except that there was an almost five-time increase in cannabis dependence in alcoholic group. There were slightly more males among the alcoholics (M/F ratio = 237/235 = 1.01) than the unaffected (M/F ratio = 274/303 = 0.90) in this dataset.
