Interaction between two independent CNR1 variants increases risk for cocaine dependence in European Americans

Abstract We recently reported that, in a European-American (EA) sample, the interaction between two cannabinoid receptor 1 gene (CNR1) variants significantly increased risk for drug dependence (DD), including cocaine dependence (CD). The present study aimed to investigate directly the association between CNR1 and CD in four independent samples. Eight markers across the 45kb CNR1 region and four large samples, i.e., family-based European-American (EA) sample (n=734), case-control EA sample (n=862), family-based African-American (AA) sample (n=834) and case-control AA sample (n=619) were