In summary, using a family-based association test in extended alcoholic pedigrees, we found evidence of association of SNPs in the NPY receptor genes NPY2R, and NPY5R with alcohol dependence, comorbid alcohol and cocaine dependence, alcohol withdrawal, and cocaine dependence phenotypes which were identified previously in the animal literature. These results indicate that sequence variations in NPY receptor genes are associated with alcohol dependence, particularly a severe subtype of alcohol dependence characterized by withdrawal symptoms, comorbid alcohol and cocaine dependence or cocaine dependence.
