The ethics of biomarker-based preclinical diagnosis of Alzheimer’s disease

Abstract

In older adults who are developing Alzheimer-typical pathology but do not experience any symptoms—a condition termed “preclinical” Alzheimer’s disease—the individual prognostic value of current biomarkers is low. Only a minority of those who have positive findings on biomarkers in the cerebrospinal fluid or upon brain imaging experience cognitive decline within 3–5 years. On the other hand, the majority of people who have negative biomarker results remain cognitively intact. This may be expected in research settings where alternative causes of cognitive impairment are infrequent. The main reasons for the poor predictive performance of biomarkers in asymptomatic individuals are the dynamic na..