Cerebrospinal fluid-based neurochemical dementia diagnostics (CSF-NDD) is meanwhile validated on S3 evidence level and international dementia guidelines like those of the German neuropsychiatric associations (DGPPN, DGN; http://www.DGPPN.de) recommend CSF-NDD for the improved early and differential diagnostics of multigenetic (sporadic) Alzheimer's Dementia (AD). CSF-NDD does also offer a predictive diagnosis of incipient AD for high-risk patients when they are still within the prodromal stage of mild cognitive impairment (MCI). But since currently no (secondary) preventive therapy of AD is available, the use of CSF-NDD for the predictive molecular diagnosis of AD is not recommended by the latter guidelines. However, molecular diagnostics of preclinical AD by CSF-NDD and/or [18F]Amyloid-PET has meanwhile gained high clinical relevance for therapeutic clinical research, as this novel clinical model allows to systematically screen for promising (secondary) preventive therapy options. Moreover, future blood based neurochemical diagnostics of preclinical or early AD by means of multiplex assays seems to be promising. However, so far blood assays were not consistently validated by independent research groups and in contrast to CSF-NDD a blood-based diagnosis of AD is not yet available.