LAUSR

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, diseasemodifying 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). Their overall conclusion is clear—screening for high risk of developing AD dementia to select those who are eligible for treatment is ethically problematic, unless extremely effective treatment becomes available. An additional major challenge is that diagnostic test accuracy is generally poor, with a particularly high risk of falsepositive results, that is, biological evidence of Alzheimer pathology in persons who will never develop dementia. The risk of overmedicalisation is serious, and the potential harms of screening for AD should not be ignored, as Le Couteur c.s. previously argued. In short, there is no evidence base for any form of screening for AD whether in a preclinical stage (an entity that in itself is disputed) or (early) symptomatic stage.