In 1978, Regier and colleagues (1) coined the term “de facto mental health and substance abuse system” after finding that most patients with mental illness and substance abuse are treated in the general medical sector, not in psychiatric settings. Despite the availability of this system, many patients with mental disorders and substance abuse do not receive a diagnosis, and many do not receive treatment or are treated for a “medical problem” instead of their underlying mental or substance abuse disorder. We polled journal editors from leading substance abuse, psychiatric, and general medical journals, as well as leaders in addiction medicine, to develop a list of important recent articles in this area. The literature described in this Update is intended to expand on and in some cases introduce information about addiction medicine that may not be readily available to internists. The information is broadly divided into categories of addiction medicine: nomenclature, alcohol, opioids, tobacco, cocaine, club drugs, marijuana, and psychogenetics.