The Alzheimer's Disease Neuroimaging Initiative is the largest public-private partnership on brain research underway at the National Institutes of Health. This 6-year study tracks cognitive and brain changes in normal subjects, those with mild cognitive impairment, and individuals with Alzheimer's disease. It was designed to provide better tools for performing effective clinical trials, and is slated to run until 2010. While data are being generated and analyzed, researchers involved in the study are developing an extension, i.e., the Alzheimer's Disease Neuroimaging Initiative II. The Foundation for the National Institutes of Health and the Alzheimer's Association convened a meeting to review the progress, evaluate future directions, and obtain the United States Food and Drug Administration's perspective on how the Alzheimer's Disease Neuroimaging Initiative could affect the drug-approval process.