Jeffrey P. Staab, M.D., Mayo Clinic psychiatrist, discusses the concepts that led to the development of the new terminology for the fifth edition of the Diagnostic and Statistical Manual of Mental Disorders (DSM-5). In DSM-4 somatic symptom disorders were defined negatively, by what they were not. Conversely, the DSM-5 emphasizes a couple core somatic symptom disorders and identifies the key features that can help determine the presence of these disorders. The DSM-5 looks to identify patterns of symptoms that can be identified positively, not the absence of a medical explanation or presumption of a psychological conflict. The change in nomenclature is the next step in the ever-evolving definition of these disorders.