The present invention relates to the diagnosis, risk assessment, prevention, and treatment of Senile Dementia of the Alzheimers Type (SDAT). More specifically the present invention relates to the measurement of ethanolamine phospholipids in human serum. Subsets of these molecules are significantly altered in subjects with pathologically confirmed deposits of β-amyloid versus subjects without β-amyloid deposits and in subjects with a clinical manifestation of dementia consistent with a diagnosis of SDAT versus non-demented controls. Further, the invention relates to the diagnosis of various stages of SDAT, the early detection and prevention of SDAT symptoms, the treatment of SDAT, the differential diagnosis of non-SDAT dementia, and the identification of molecular targets for which chemical or biological treatments can be designed for the therapeutic intervention of SDAT. The present invention also relates to methods of using a molecular diagnostic assay to direct and select the appropriate therapeutic intervention for subjects suffering from dementia. The present invention also relates to small molecules or metabolites that are found to have significantly different abundances between persons with a clinical manifestation of SDAT and normal, non-demented patients.
