As mentioned above, there is minimal CSF data and imaging is only beginning. Thus biomarkers for AD in DS are less developed than in the general population. Additional biomarkers could be helpful in studying AD in DS. A biomarker that could increase the ability to predict transition to dementia in an individual (as opposed to the investigators current ability on a population level) would increase the efficiency of any study. The ability to track the progression or improvement of dementia might also be useful. If a biomarker indicated transition to dementia earlier than any clinical instrument, a prevention study could conceivably be conducted at younger ages with greater chance of success. In addition to DS, such a biomarker would also be useful in the general population.