1. Sant Pau Memory Unit, Department of Neurology, Hospital de la Santa Creu i Sant Pau, Biomedical Research Institute Sant Pau, Universitat Autònoma de Barcelona, Barcelona, Spain
2. Center of Biomedical Investigation Network for Neurodegenerative Diseases (CIBERNED), Madrid, Spain
3. Barcelona Down Medical Center, Fundació Catalana Síndrome de Down, Barcelona, Spain
4. Multidisciplinary Sleep Unit, Respiratory Department, Hospital de la Santa Creu i Sant Pau, Barcelona, Spain
5. Hospital del Mar, Barcelona, Spain
6. Nuclear Medicine Department, Hospital de la Santa Creu i Sant Pau, Barcelona, Spain
7. Cambridge Intellectual and Developmental Disabilities Research Group, Department of Psychiatry, University of Cambridge, Douglas House, Cambridge, United Kingdom
8. Healthy Brain Aging and Sleep Center, Department of Psychiatry, New York University Grossman School of Medicine, New York
9. Clinical Research Support Unit, Bellvitge Biomedical Research Institute Department of Clinical Pharmacology, University of Barcelona, Barcelona, Spain
10. Le Laboratoire de Biochimie et Protéomique Clinique, Université Montpellier, Centre Hospitalier Universitaire Montpellier, Institut National de la Santé et de la Recherche Médicale, Montpellier, France
11. Department of Psychiatry and Neurochemistry, Institute of Neuroscience and Physiology, the Sahlgrenska Academy at the University of Gothenburg, Mönldal, Sweden
12. Clinical Neurochemistry Laboratory, Sahlgrenska University Hospital, Mölndal, Sweden
13. UK Dementia Research Institute at University College London (UCL), London, United Kingdom
14. Department of Neurodegenerative Disease, UCL Queen Square Institute of Neurology, London, United Kingdom
15. Cambridgeshire and Peterborough National Health Service (NHS) Foundation Trust, Fulbourn Hospital, Elizabeth House, Cambridge, United Kingdom