Addiction medicine/psychiatry, a medical subspecialty founded on October 1991 by the American Board of Psychiatry and Neurology, was granted as subspecialty within psychiatry. It mainly deals with medical assessment, diagnosis and treatment of subjects who suffer from an addiction (i.e. drug and/or alcohol addiction; gambling; sexual addiction; game addiction; and so on). Addiction psychiatry also deals with subjects in dual diagnosis, i.e. individuals with addiction issues along with co-occurring psychiatric disorders. However, despite its well established “dignity” to be part of psychiatry, most mental health's professionals believe that it is not a primarily psychiatric field due to the frequent co-occurrence of internistic/medical issues. In addition, the situation of psychiatric training specifically addressed to addiction is widely diversified across the European countries. Therefore, most psychiatrists do not possess specific qualifications and formation on this increasing field of psychiatry. The present lecture aims at providing an insight into the issues related to the diatribe between psychiatry and medicine on addiction medicine/psychiatry, specifically focusing on differences across European countries.