My assessment is that the existing research already shows that certain blood tests convey as much diagnostic certainty as the far more invasive and expensive PET scans and lumbar puncture cerebro-spinal fluid tests. With certain other tests, the FDA has attached a commitment that they only be ordered in conjunction with counseling regarding their results. That might be a good idea.

I know that many Alzheimer's researchers have voiced their opposition to having these tests readily available. But that seems largely based on their own preferences about how they would want to proceed (or not) in their own lives. That doesn't seem to me to be a reasonable standard to impose on others.

I don't think much marketing would be needed. Many, many individuals wan't to understand their likelihood of being able to function independently a decade from now.