Should interventions to treat or prevent Alzheimer’s disease be tested in a population or as targeted treatment of highly selected study participants?

Symptomatic treatments for Alzheimer’s disease should retain a place in the advanced stages of disease since their actions on these symptoms, even if not modifying the course of disease, are critical for improving patients’ comfort and reducing the burden felt by caregivers, especially those facing behavioral disorders. In mild or prodromal stages, the opportunity to act on specific pathophysiological targets should be considered. These targeted and tailored therapies have the greatest chance to be active in the early stages of disease, in the context of heterogeneous pathological mechanisms to be specified by reliable and accessible biomarkers. Finally, interventional approaches in large populations seem particularly appropriate for prevention strategies.