Medicalization is, by definition, about the extension of medical boundaries. Analogous to "domain expansion, " extant medicalized categories can expand to become broader and more inclusive. This paper examines the emergence of Attention Deficit Hyperactivity Disorder (ADHD) in adults. ADHD, commonly known as Hyperactivity, became established in the 1970s as a diagnosis for children; it expanded first to include "adult hyperactives" and, in the 1990s, "ADHD Adults." This allowed for the inclusion of an entire population of people and their problems that were excluded by the original conception of hyperactive children. We show how lay, professional, and media claims help establish the expanded diagnostic category. We identify particular aspects of the social context that contributed to the rise of adult ADHD and outline some of the social implications of ADHD in adults, especially the medicalization of underperformance and the availability of new disability rights. Adult ADHD serves as an exemplar of several cases of diagnostic expansion, an important avenue of increasing medicalization. Over the past thirty years there has been keen sociological interest in the medicalization of deviance and social problems (Conrad 1992, 2000; Conrad and Schneider 1992; Zola 1972). By now, there are dozens of case examples of medicalization and a body of literature has accumulated that has loosely been called "medicalization theory" (see Williams and Calnan 1996). At this point, it is important to build on this corpus of knowledge to better understand different aspects of medicalization. Medicalization is, by definition, about the extension of medical jurisdiction or the expansion of medical boundaries. In different situations, medical professionals (Halpern 1990), political reformers (Haines 1989), lay activists (Schneider 1978), or social movements (Scott 1990) have promoted boundary expansion. Most medicalization studies focus on how nonmedical problems become defined as medical problems, usually as illnesses or disorders. But there has been less examination of how medicalized categories themselves can be subjects of expansion, thus, engendering further medicalization. It seems clear by now that medicalization of social problems is not an either/or phenomenon, but that it is better conceptualized in terms of degrees of medicalization. Some conditions are almost fully medicalized (e.g., death, childbirth), others are partly medicalized (e.g., opiate addiction, menopause), and still others are minimally medicalized (e.g., sexual addiction, spouse abuse). One dimension of the degree of medicalization is the elasticity of a medical category. "While some categories are narrow and circumspect, others can expand and incorporate a number of other problems" or be applied to new populations (Conrad 1992, p. 221). For example, Alzheimer's Disease (AD) was once an obscure disorder, but with the removal of "age" as a criteria (Fox 1989), there was no longer a distinction between AD and senile dementia. This Our thanks to Joel Best, Libby Br...
