DRD2 and alcohol dependence: The study has analyzed only the COMT and DRD2 polymorphisms, which the authors are going to expand on in their further studies with additional experiments on polymorphisms of the 5—HTTLPR (serotonin-transporter-linked polymorphic) gene for a full neurobiological reference to the Cloninger alcohol dependence typology and the TCI temperament and character questionnaire, such as inter alia [69,72].