Here, we conduct a GWAS of a phenotype representing alcohol or illicit drug (i.e., cannabis, cocaine, sedatives, stimulants and/or opioids) dependence (ANYDEP) among 7,291 European-Americans (EA; 2,927 cases) and 3,132 African-Americans (AA: 1,315 cases) participating in the family-based Collaborative Study on the Genetics of Alcoholism (COGA). COGA participants were recruited from extended families, most of which were ascertained for alcohol dependence. The ANYDEP phenotype is particularly well suited for this ascertained sample as drug dependence more commonly co-occurs with alcohol dependence than with dependence on any other substance22,23. We conducted ancestry-specific analyses in EAs and AAs followed by a trans-ancestral meta-analysis (EA+AA) to identify loci associated with ANYDEP, i.e., dependence on any one or a combination of alcohol, cannabis, cocaine, sedatives, stimulants and/or opioids. For genome-wide significant (GWS) associations, we performed secondary analyses evaluating associations with individual alcohol and drug dependence diagnoses, and to examine whether the exclusion of those cases who met criteria only for alcohol dependence altered the association. Replication was attempted in two small independent samples that contained EA and AA individuals and substance dependence phenotypes, the
