DESCRIPTION (Adapted from the application): The Clinical Core functions to maintain an active cohort of at least 400 volunteer patients (including Alzheimer's disease, related dementias, and individuals with Down syndrome and dementia) and 150 non-demented, elderly controls (age 75 and up) who are evaluated annually, are willing to participate in research, and have, consented to autopsy. The additional 148 non-demented controls under 75 years of age are evaluated every two years. By the next renewal period the recruitment of patients is proposed to include those who are in the mild stages of dementia and present with focal cognitive impairments to meet both clinical and neuropathological research needs. The investigators propose to recruit additional controls to address the increasing need for control brain tissue by the Neuropathology Core. All data from annual clinical evaluations and the neuropathological evaluation, when appropriate, are managed by the Administrative Core and stored in the Alzheimer's Center database and include detailed, longitudinal behavioral and neuropathological data available for use in various research projects. The Clinical and Neuropathology Cores are united via this data management system that facilitates research links between clinical and basic sciences. The Clinical Core will also continue to foster novel approaches to improve diagnostic methods and continue developing techniques for evaluating ethnically diverse, non-English speaking subjects. By building upon the already established reputation in studies of leaning and memory, the Core will also facilitate the study of brain systems and circuits and relate these to specific clinical presentations, brain imaging, and neuropathological measures. The Clinical Core provided resources for 34 investigators during the last funding cycle and generated over 74 published papers. The Core's overriding priority is to ensure patient privacy and well being, and research projects will incorporate potential therapies whenever possible.