I am involved in cohort studies (PICNICS, ICICLE-PD, Proband) which are observational studies tracking the progression of patients with Parkinson?s disease (PD) over several years so that we can better understand how the disease behaves over time. The studies recruited a large group of patients who were newly diagnosed with PD and follow them up every 6-18 months with clinical assessments and cognitive tests. A subset of patients had brain scans and lumbar punctures. The main aim of my research is to help us better understand why some people with Parkinson?s disease develop memory difficulties, as the reason for this is currently poorly understood. As longer follow-up data becomes available from these studies, it will help us to discover what group of patients with Parkinson?s disease are more likely to develop dementia and how we can better treat it.