Although a major goal of the Alzheimer's Disease Neuroimaging Initiative (ADNI) project has been the creation of a brain imaging and biomarker database with rapid public access to all raw and processed data, no funds were included in the initial ADNI proposal for exploratory bio-fluid proteomic or metabolomic work. As a result, the ADNI Industry Scientific Advisory Board (ISAB) convened a small group of proteomic/metabolomic experts to develop an add-on proposal with the intent of characterizing promising bio-fluid biomarker candidates for Alzheimer's Disease (AD). The first phase of this project, a plasma-based proteomic proposal, has already been approved and funded by the Biomarkers Consortium and is currently an active project being executed by the Consortium. The present proposal represents a follow-on to the first phase of this project (the plasma-based study) and will seek to qualify a Cerebral Spinal Fluid-based (CSF-based) multiplex panel using the same patient cohort.