This is an article about recent research into the supposed link between beta amyloid and Alzheimer's, still the predominant focus in the search for dementia drugs that might actually work.
It seems to me to contain some bizarre explanations as to why the researchers' investigations do not produce exactly the results which they have convinced themselves are inevitable.
This is perhaps the best example, but you will see several others if this interests you enough to try to follow the article:
'previous trials of anti-amyloid drugs on people with dementia failed because their brains were already too damaged or because some patients, not screened for amyloid, may not have had Alzheimer’s.'
So I wonder what disease it was that was wrecking the lives of those patients who had been diagnosed with AD but did not screen for amyloid?