For our primary phenotype, we employed the DSM-IV criteria for alcohol dependence (American Psychiatric Association 1994), which could be derived from the SSAGA data; we used the broader COGA definition as a secondary phenotype. The vast majority of individuals who met DSM-IV criteria also met COGA criteria; 35 individuals who were positive for DSM-IV but negative for COGA criteria and 22 individuals who were positive for COGA criteria but negative for DSM-IV were coded as unknown and omitted from analysis (Table 1).
