Alzheimer's Disease Neuroimaging Initiative (ADNI) is a multisite study that aims to improve clinical trials for the prevention and treatment of Alzheimer's disease (AD). This cooperative study combines expertise and funding from the private and public sector to study subjects with AD, as well as those who may develop AD and controls with no signs of cognitive impairment. Researchers at 63 sites in the US and Canada track the progression of AD in the human brain with neuroimaging, biochemical, and genetic biological markers. This knowledge helps to find better clinical trials for the prevention and treatment of AD. ADNI has made a global impact, firstly by developing a set of standardized protocols to allow the comparison of results from multiple centers, and secondly by its data-sharing policy which makes available all at the data without embargo to qualified researchers worldwide. To date, over 1000 scientific publications have used ADNI data. A number of other initiatives related to AD and other diseases have been designed and implemented using ADNI as a model. ADNI has been running since 2004 and is currently funded until 2021. Primary goals Detect the earliest signs of AD and to track the disease using biomarkers. validate, standardize, and optimize biomarkers for clinical AD trials. to make all data and samples available for sharing with clinical trial designers and scientists worldwide. History and funding The idea of a collaboration between public institutions and private pharmaceutical companies to fund a large biomarker project to study AD and to speed up progress toward effective treatments for the disease was conceived at the beginning of the millennium by Neil S. Buckholz at the National Institute on Aging (NIA) and Dr. William Potter, at Eli Lilly and Company. The Alzheimer's Disease Neuroimaging Initiative (ADNI) began in 2004 under the leadership of Dr. Michael W. Weiner, funded as a private – public partnership with $27 million contributed by 20 companies and two foundations through the Foundation for the National Institutes of Health and $40 million from the NIA. The initial five-year study (ADNI-1) was extended by two years in 2009 by a Grant Opportunities grant, and in 2011 and 2016 by further competitive renewals of the ADNI-1 grant (ADNI-2 and ADNI-3, respectively) (Table 1). Enrollment of participants ADNI enrolls participants between the ages of 55 and 90 who are recruited at 57 sites in the US and Canada. One group has dementia due