In this really interesting essay, Michalon et al discuss defining Alzheimer’s disease in response to recent discussions on revising the definition and diagnostic criteria for the condition. The essay provides interesting historical context to the debate.
Recent revisions of Alzheimer’s Disease (AD) definitions by two leading research groups—the Alzheimer’s Association and the International Working Group—reflect divergent approaches: the former promotes a strictly biological definition, while the latter promotes a clinicalbiological construct. We contend that this emerging controversy is not merely semantic, but scientifically, clinically, and politically significant. Drawing on philosophical tools and situating the current debate within a broader historical context from the reconceptualization of AD in the 1970s onwards, we explore how definitions can serve as transformative instruments, acting as strategic bets that reshape scientific fields and clinical practices. Ultimately, we draw from the AD case study to argue for a critical reflection on the risks and promises of such definitional acts. We also propose a renewed attention to the ‘ethics of stipulating’ in the field of contemporary biomedical sciences.
In response to advances in diagnostics and therapeutics, two major research groups specialising in Alzheimer’s disease (AD) have recently revised their definition and diagnostic criteria for the condition. While they concur on certain aspects—most notably, the centrality of amyloid and tau pathologies—the two groups have proposed different types of definition. The Alzheimer’s Association (AA) group asserts the following fundamental principle: “AD is defined by its unique neuropathologic findings; therefore, detection of AD neuropathologic change by biomarkers is equivalent to diagnosing the disease” 1(p.5145). This definition regards specific biological changes as the unique defining feature rather than a joint characteristic, together with specific symptoms, of a disease. In this framework, asymptomatic individuals can be diagnosed with ‘preclinical AD’