A US Study That Observes How Parkinson's Disease Changes Over Time in Patients Who Still Have Movement Symptoms Despite Taking Parkinson's Medications

This is an observational study in which data are collected and studied from Parkinson's disease patients who have movement symptoms despite taking standard Parkinson's medications. In observational studies, observations are made without any changes to the participant's healthcare or treatment plan. No investigational product will be administered in this study, as participants will be treated with the standard of care that medical experts currently consider most appropriate. Parkinson's disease (PD) is a condition that affects the brain and causes problems with movement and other body functions. The symptoms of Parkinson's disease can worsen over time. People with Parkinson's disease may experience shaking (tremor), slow movements, stiff muscles, trouble walking, and problems with balance. They can also have other symptoms, such as difficulty thinking clearly, changes in mood, or difficulty sleeping. Parkinson's disease mostly affects older adults, but it can happen to younger people too. There is no cure, but treatments can help manage the symptoms and improve quality of life. While doctors and researchers know that Parkinson's disease affects people in different ways and can worsen over time, there are still many things they don't fully understand-especially for people who experience movement symptoms despite taking their usual Parkinson's medicines. Earlier studies did not follow these patients long enough or collect all the important information needed. This study is being done to fill those gaps. The main purpose of this study is to better understand how Parkinson's disease changes over time in patients who experience movement symptoms while taking standard oral Parkinson's medications, what challenges patients and their care partners face, and how their treatments are working in real life. To do this, researchers will collect data on: * Sociodemographics (e.g. age, gender, race/ethnicity, insurance provider). * Medical history and vital signs (e.g. comorbidities, family history of Parkinson's, height, weight, blood pressure). * Medications and treatments (e.g. Parkinson's and non-Parkinson's medications and other treatments, rehabilitation therapy sessions, use of mobility assistance devices). * Movement symptoms (e.g. tremor, slow movement, balance). * Non-movement symptoms (e.g. cognition, mood, sleep, activities of daily living). * Molecular data (e.g. genetics, α-synuclein). * Burden of care (e.g. economic cost). Data will come from questionnaires or rating scales conducted by the doctor with the patient during study visits, diaries and logs completed by the patient, medical records, health insurance claims records, blood samples and skin biopsies, a digital device that records movement/non-movement symptoms, and questionnaires completed by the care partner. Data will be collected from December 2025 to December 2032. Each participant may be followed for up to 5 years.