Diagnostic Domain Defense: Autism Spectrum Disorder and the DSM-5

A central mechanism by which medicalization occurs is through domain expansion, wherein an existing diagnostic definition widens to include cases beyond its original scope. This has been especially commonplace with respect to mental illness diagnoses. In contrast, there are few clear instances of domain contraction. The controversy surrounding the revi-sions to autism in advance of the publication of the fifth edition of the Diagnostic and Statistical Manual of Mental Disorders (DSM-5) is thus of considerable importance. Many autism advocates feared the new definition of autism would exclude a significant number of individuals who are already diagnosed. We examine lay claims making to this perceived instance of domain contraction through a content analysis of online reader comments to a high-profile New York Times article reporting on the DSM-5 autism criteria. Our analysis points to an amorphous group of social stakeholders who express a variety of concerns about unabated medicalization. We also identify the stance of diagnostic domain defense, which is an oppositional response by laypeople with a personal connection to a diagnosis to a real or perceived challenge to the definitional boundaries of that diagnosis. Our analysis explicates the dimensions of diagnostic domain defense, which include its grounding in ex-periential certainty and anguish, and the accrual and deployment of diagnostic resources. We make a case for the utility of this concept for theorizing the relationship between lay claims making, diagnoses, and medicalization. We also make a case for the use of online reader comments as a way to unobtrusively study lay claims making related to pressing so-cial problems in the Internet era