The present invention provides compositions and methods useful for diagnosing, treating, and monitoring alcohol dependence and disorders and susceptibility to alcohol dependence disorders, as well as drug related dependence and disorders. The present invention also relates to methods and assays useful for determining whether a subject has a predisposition to developing an addictive disease or disorder, determining whether a subject will be responsive to particular treatments, and compositions and methods useful for treating a subject in need of treatment. The present invention also relates to compositions and methods useful for treating subjects having an addictive disease or disorder (or who are predisposed thereto) based on identification of genetic markers indicative of a subject being predisposed to such disease or disorder or being predisposed to responding to treatment thereof.
