The Alzheimer field is in desperate need for an effective treatment. After decades of research, the available drugs treat only symptoms, and even their effectiveness is disputed. Because brain changes precede the clinical symptoms by years to decades, disease-modifying treatments should probably be started early, when the first symptoms occur—or even before. But how to determine who to treat? In this issue, Erik Gustavsson c.s. approach this question by addressing the benefits, harms and ethical issues encountered when using different modes of screening for ‘preclinical’ or early symptomatic Alzheimer disease (AD).
An additional major challenge is that diagnostic test accuracy is generally poor, with a particularly high risk of false-positive results, that is, biological evidence of Alzheimer pathology in persons…