Assistance Publique-Hôpitaux de Paris (AP-HP) Department of Neurology, Sorbonne University, Paris, France; Institut du Cerveau, Sorbonne University, Paris, France. Electronic address: bruno.dubois@aphp.fr. Assistance Publique-Hôpitaux de Paris (AP-HP) Department of Neurology, Sorbonne University, Paris, France; Institut du Cerveau, Sorbonne University, Paris, France. Laboratory of Neuroimaging of Aging (LANVIE), University of Geneva, Geneva, Switzerland; Memory Clinic, University Hospital of Geneva, Geneva, Switzerland; Laboratory of Alzheimer's Neuroimaging and Epidemiology (LANE), Saint John of God Clinical Research Centre, Brescia, Italy. Memory and Aging Center, Department of Neurology and Department of Radiology and Biomedical Imaging, University of California San Francisco, San Francisco, CA, USA. Cleveland Clinic, Lou Ruvo Center for Brain Health, Las Vegas, NV, USA. University School for Advanced Studies, Pavia, Italy; RCCS Mondino Foundation, Pavia, Italy. Sant Pau Memory Unit, Department of Neurology, Hospital de la Santa Creu i Sant Pau, Universitat Autonoma de Barcelona, Barcelona, Spain; Biomedical Research Institute, Hospital de la Santa Creu i Sant Pau, Universitat Autonoma de Barcelona, Barcelona, Spain; Network Center for Biomedical Research in Neurodegenerative Diseases (CIBERNED), Madrid, Spain. Assistance Publique-Hôpitaux de Paris (AP-HP) Department of Neurology, Sorbonne University, Paris, France; INSERM, CHU Lille, U1171 - Degenerative and vascular cognitive disorders, University of Lille, Lille, France. Assistance Publique-Hôpitaux de Paris (AP-HP) Department of Neurology, Sorbonne University, Paris, France; Inria ARAMIS project team, Inria-APHP collaboratio, Sorbonne University, Paris, France; Institut du Cerveau, Sorbonne University, Paris, France. Assistance Publique-Hôpitaux de Paris (AP-HP) Department of Neurology, Sorbonne University, Paris, France. AP-HP Department of Nuclear Medicine, Sorbonne University, Paris, France; CNRS, INSERM, Laboratoire d'Imagerie Biomédicale, Sorbonne University, Paris, France; Institut du Cerveau, Sorbonne University, Paris, France. Department of Neurobiology, Care Sciences and Society, Center for Alzheimer Research, Karolinska Institute, Stockholm, Sweden; Theme Aging, The Aging Brain, Karolinska University Hospital, Stockholm, Sweden. Institute of Neuroscience and Physiology, Department of Psychiatry and Neurochemistry, The Sahlgrenska Academy at the University of Gothenburg, Mölndal, Sweden; Clinical Neurochemistry Laboratory, Sahlgrenska University Hospital, Mölndal, Sweden. Department of Neurosciences, University of California San Diego, La Jolla, CA, USA. Cognitive Neuroscience Division, Department of Neurology, Columbia University, New York, NY, USA. Department of Molecular Imaging and Therapy, Austin Health, The University of Melbourne, Melbourne, VIC, Australia. Department of Neurology and Department of Psychiatry, Alpert Medical School of Brown University, Providence, RI, USA; Butler Hospital, Providence, RI, USA. Keck School of Medicine of the University of Southern California, Los Angeles, USA. Cleveland Clinic, Lou Ruvo Center for Brain Health, Las Vegas, NV, USA; Chambers-Grundy Center for Transformative Neuroscience, Department of Brain Health, School of Integrated Health Sciences, University of Nevada Las Vegas, Las Vegas, NV, USA. Department of Neurosciences, University of California San Diego, La Jolla, CA, USA; Shiley-Marcos Alzheimer's Disease Research Center, University of California San Diego, La Jolla, CA, USA; Alzheimer Disease Cooperative Study, University of California San Diego, La Jolla, CA, USA.