DC Longitudinal Study on Aging and Specimen Bank

These studies will examine the feasibility of using various biochemical assays in blood, and/or cerebrospinal fluid, genetic testing, cognitive status assessments, and lifestyle questionnaires to aid in the ante-mortem diagnosis of Alzheimer's and other neurodegenerative diseases.

Subjects have 2 options for participation. They may solely participate in the main study or the main study and the longitudinal substudy. The main study includes a single visit at which demographic and medical information will be recorded, brief cognitive testing, and blood and/or cerebrospinal fluid (CSF)(optional) specimens will be collected for the research assays. Genetic testing will take place. No clinical laboratory testing will be done and no results will be communicated to subjects.

During the Longitudinal substudy, each subject will be asked to participate in ongoing longitudinal study visits at which demographic and medical information will be recorded, cognitive testing and lifestyle questionnaire collection will occur, and blood and/or cerebrospinal fluid (CSF) specimens will be collected for the research assays. I

If one is eligible and agrees to participate in the longitudinal sub-study, they will be asked to come into the clinic for an Initial Study Visit, and then return every year or every other year, depending on which group they fit into (Cognitively Normal (CN), Mild Cognitive Impairment (MCI), Alzheimer's Disease (AD), other neurodegenerative disease) for ongoing Follow-Up Clinic Visits.

CN participants will come into the clinic every other year, with telephone checks occurring on alternating years, until the study ends.