Pieter Jelle Visser is a clinical epidemiologist who investigates the pathophysiology, diagnosis, prognosis and treatment of neurodegenerative disorders, including Alzheimer’s disease (AD), Parkinson’s disease (PD) and Lewy body dementia (DLB). His main research focus is the heterogeneity found in proteins in cerebrospinal fluid between one individual and another. The hypothesis is that people with the same disease, such as PD, may still require different treatments. Dr Visser has set up a number of initiatives to improve access to existing data and samples to accelerate research in the neurodegenerative field, including Descripa, the amyloid biomarker study, BIOMARKAPD, EMIF-AD and EPND. His studies have produced landmark publications in JAMA, Nature Aging and other journals.