Just Semantics? How Diagnostic Criteria Influence Physician-Patient Narratives in Alzheimer’s Disease

Introduction: The current diagnosis of Alzheimer’s disease (AD) is shaped by the Alzheimer’s Association (AA) and the International Working Group (IWG) criteria. While both frameworks lead to similar physician-patient conversations when disclosing biomarker results to patients with cognitive impairment, they diverge significantly for cognitively unimpaired individuals. The aim of this paper is to explore these differences and their associated epistemological and ethical implications, through simulated, case-based physician-patient conversations. Methods: The conversations were developed on the basis of clinical experience, exchanges with patients and carers, insights from a targeted narrative literature review and were subsequently refined with large language model assistance. Results: Our analysis highlights that the AA framework reinforces a deterministic narrative by equating amyloid biomarker positivity with disease and raising a misunderstanding with illness. In contrast, the IWG framework is consistent with the incomplete penetrance of AD pathology and frames biomarker positivity in cognitively unimpaired individuals as a risk condition. We acknowledge that the IWG framework enables more complex but also more realistic physician-patient conversations. Conclusion: Physician-patient conversations employing a carefully selected lexicon, reflecting patient-centred outcomes, may promote patient engagement, compliance with medical recommendations, and, ultimately, societal trust in medicine and physicians.