1 StoP-AD Centre, Douglas Mental Health University Institute, McGill University, Montréal, Quebec, Canada.
2 Department of Psychiatry, McGill University, Montréal, Quebec, Canada.
3 McConnell Brain Imaging Center, Montreal Neurological Institute, McGill University, Montréal, Quebec, Canada.
4 Cerebral Imaging Centre, Douglas Mental Health University Institute, McGill University, Montréal, Quebec, Canada.
5 Integrated Program in Neuroscience, McGill University, Montréal, Quebec, Canada.
6 Research Center of the CIUSSS-NIM, Hôpital du Sacré-Coeur de Montréal, Montreal, Quebec, Canada.
7 Department of Medicine, Faculty of Medicine, Université de Montréal, Montréal, Quebec, Canada.
8 Department of Physics, Concordia University, Montréal, Quebec, Canada.
9 Department of Neurology and Neurosurgery, McGill University, Montréal, Quebec, Canada.
10 Faculté des sciences, Département d'informatique, Université de Sherbrooke, Sherbrooke, Quebec, Canada.
11 Normandie Univ, UNICAEN, INSERM, U1237, PhIND "Physiopathology and Imaging of Neurological Disorders", NeuroPresage Team, GIP Cyceron, Caen, France.
12 School of Psychological Science, The University of Western Australia, Perth, Western Australia, Australia.
13 Department Biomedical Engineering, McGill University, Montréal, Quebec, Canada.
14 Centre ÉPIC, Montreal Heart Institute, Montréal, Quebec, Canada.
15 School of Health, Concordia University, Montréal, Quebec, Canada.
16 Faculty of Dental Medicine and Oral Health Sciences, McGill University, Montreal, Quebec, Canada.
17 Department of Anesthesia, Faculty of Medicine and Health Sciences, McGill University, Montreal, Quebec, Canada.
18 Alan Edwards Center for Research on Pain, McGill University, Montreal, Quebec, Canada.
19 Department of Psychology, Toronto Metropolitan University, Toronto, Ontario, Canada.
20 Clinique interdisciplinaire de mémoire, CHU de Québec affilié à l'Université Laval, Québec, Quebec, Canada.
21 Division of Neurology, Department of Medicine, Faculty of Medicine and Health Sciences, Université de Sherbrooke, Sherbrooke, Quebec, Canada.
22 AI2D Center for AI and Data Science for Integrated Diagnostics, University of Pennsylvania, Philadelphia, Pennsylvania, USA.
23 Psychology Department, Université de Montréal, Montréal, Quebec, Canada.
24 Centre de Recherche de l'Institut Universitaire de Gériatrie de Montréal, Montréal, Quebec, Canada.
25 Department of Psychiatry and Neurochemistry, Institute of Neuroscience and Physiology, Sahlgrenska Academy, University of Gothenburg, Mölndal, Sweden.
26 Clinical Neurochemistry Lab, Sahlgrenska University Hospital, Mölndal, Sweden.
27 Paris Brain Institute, ICM, Pitié-Salpêtrière Hospital, Sorbonne University, Paris, France.
28 Neurodegenerative Disorder Research Center, Division of Life Sciences and Medicine, and Department of Neurology, Institute on Aging and Brain Disorders, University of Science and Technology of China and First Affiliated Hospital of USTC, Hefei, Anhui, P.R. China.
29 Department of Neurodegenerative Disease, University College London Institute of Neurology, London, UK.
30 UK Dementia Research Institute at UCL, London, UK.
31 Hong Kong Center for Neurodegenerative Diseases, InnoHK, Hong Kong, China.
32 Wisconsin Alzheimer's Disease Research Center, University of Wisconsin School of Medicine and Public Health, University of Wisconsin-Madison, Madison, Wisconsin, USA.
33 Department of Physiology and Pharmacology, Université de Montréal, Montréal, Quebec, Canada.
34 Clinical Memory Research Unit, Department of Clinical Sciences Malmö, Lund University, Lund, Sweden.

The PResymptomatic EValuation of Experimental or Novel Treatments for Alzheimer's Disease (PREVENT-AD) is an investigator-driven study that was created in 2011 and enrolled cognitively normal older adults with a family history of sporadic AD. Participants are deeply phenotyped and have now been followed annually for more than 12 years (median follow-up 8.0 years, SD 3.1). Multimodal magnetic resonance imaging (MRI), genetic, neurosensory, clinical, cerebrospinal fluid, and cognitive data collected until 2017 on 348 participants who agreed to open sharing with the neuroscience community were already available. We now share a new release including 6 years of additional follow-up cognitive data, and additional MRI follow-ups, clinical progression, new longitudinal behavioral and lifestyle measures (questionnaires, actigraphy), longitudinal AD plasma biomarkers, amyloid-beta and tau positron emission tomography (PET), magnetoencephalography, as well as neuroimaging analytic measures from all MRI modalities. We describe the PREVENT-AD study, the data shared with the global research community, as well as the model we created to sustain longitudinal follow-ups while also allowing new innovative data collection. HIGHLIGHTS: The PResymptomatic EValuation of Experimental or Novel Treatments for Alzheimer's Disease (PREVENT-AD) is a single-site longitudinal study that started in 2011 with annual follow-up data collection on individuals at risk of Alzheimer's disease who were all cognitively normal at enrolment. All 387 participants were enrolled between 2011 and 2017 and 306 (79%) of these participants were still in the study as of December 2023. While the PREVENT-AD dataset was not originally planned to be shared with the global research community, 348 participants retrospectively consented for their data to be shared with researchers worldwide. The first release of data was in 2019. We now share a second release that includes 6 years of additional follow-up visits, information on clinical progression and novel cognitive, behavioral, genetic, plasma and neuroimaging (amyloid and tau positron emission tomography [PET], magnetoencephalography [MEG], and new magnetic resonance imaging [MRI] sequences) data. It also includes analytic outputs for neuroimaging modalities.