1. The Norwegian National Centre for Ageing and Health Vestfold Hospital Trust Tønsberg Norway
2. Institute of Clinical Medicine Faculty of Medicine University of Oslo Oslo Norway
3. Institute of Psychiatry Psychology, and Neuroscience Department of Forensic and Neurodevelopmental Sciences, King's College London London UK
4. The London Down Syndrome (LonDownS) Consortium London UK
5. Trinity Centre for Ageing and Intellectual Disability Trinity College Dublin, Lincoln Gate Dublin Ireland
6. Global Brain Health Institute Trinity College Dublin & University of California San Francisco California USA
7. Department of Geriatric Medicine Oslo University Hospital Oslo Norway
8. Barcelona Down Medical Center Fundació Catalana Síndrome de Down Barcelona Spain
9. Department of Psychiatry University of Cambridge The Old Schools Cambridge UK
10. Cambridgeshire & Peterborough NHS Foundation Trust Fulbourn Hospital Cambridge UK
11. Department of Primary and Community Care Radboud University Medical Center Nijmegen The Netherlands
12. Institute Jerome Lejeune Paris France
13. Sant Pau Memory Unit Department of Neurology Hospital of Sant Pau, Sant Pau Research Institute Barcelona Spain
14. Centro de Investigación Biomédica en Red en Enfermedades Neurodegenerativas (CIBERNED) Monforte de Lemos Madrid Spain
15. Department of Neurology Ludwig‐Maximilians‐Universität München Munich Germany
16. German Center for Neurodegenerative Diseases Munich Germany
17. Munich Cluster for Systems Neurology (SyNergy) Munich Germany
18. Department of Neurology University Hospital Zurich Zurich Switzerland
19. Cognitive Neuropsychology Tilburg University Tilburg The Netherlands
20. South London and the Maudsley NHS Foundation Trust London UK