Intensive research is carried out to develop a disease-modifying drug for Alzheimer’s disease (AD). The development of drug candidates that reduce Aß or tau in the brain seems particularly promising. However, these drugs target people at risk for AD, who must be identified before they have any, or only moderate, symptoms associated with the disease. There are different strategies that may be used to identify these individuals (eg, population screening, cascade screening, etc). Each of these strategies raises different ethical challenges. In this paper, we analyse these challenges in relation to the risk stratification for AD necessary for using these drugs. We conclude that the new drugs must generate large health benefits for people at risk of developing AD to justify the ethical costs associated with current risk stratification methods, benefits much larger than current drug candidates have. This conclusion raises a new set of ethical questions that should be further discussed.