Understanding the pattern of cognitive decline in GBA1-related Parkinson's Disease: an exploratory longitudinal multi-cohort study

The shared code was created to perform analyses for the article "Understanding the pattern of cognitive decline in GBA1-related Parkinson’s Disease: an exploratory longitudinal multi-cohort study". This code was created to analyze data from three cohorts:1. The PPMI study, downloaded from database (RRID:SCR_006431) on May 22, 2025. NB: as the PPMI database is always evolving, it is possible that the code may not work if the database has changed since the date the code was created. 2. The “Amyloid-Beta in cerebrospinal spinal fluid as a risk factor for cognitive dysfunction in Parkinson’s Disease (ABC-PD)” study (University of Tuebingen, Germany)3. The National Centre of Excellence in Research on Parkinson's Disease (NCER-PD) study (National Centre for Excellence in Research on Parkinson’s disease/Luxembourg Institute of Health, Luxembourg) Analytic datasets are not included in the submission. Researchers can request access to PPMI data at the PPMI Study website (https://www.ppmi-info.org/access-data-specimens/download-data). The NCER-PD database is not publicly available as it is linked to the Luxembourg Parkinson’s study and its internal regulations. The NCER-PD Consortium is willing to share its available data. The ABC-PD database is not publicly available as it is linked to the internal regulations of the University Hospital of Tuebingen. The PI of the study, Prof. Inga Liepelt Scarfone, will consider any requests for access to the data reported in this manuscript (including de-identified participant data and the corresponding data dictionary).