Alzheimer’s disease has been a costly and elusive area for drug developers. Despite many promising results in early-stage trials, drug companies have seen millions of dollars of R&D investment end in spectacular late-stage failures. While treatments for the disease are desperately needed, one of the barriers to success has been the availability of diagnostics that can detect the disease at early stages when therapeutic interventions may have their best chance for success. We spoke to Rachel Laing, managing partner of Bionest Partners about the problem, whether there are fundamental misunderstandings about the disease that have sent drug companies in pursuit of the wrong targets, and why diagnostics can play a critical role in reshaping the pursuit of an effective treatment for the neurodegenerative condition.