[absolutelastone]

There's grants and studies going on for all kinds of treatments for Alzheimer's. Amyloid may be the biggest category, perhaps undeservedly, but it's still a minority of them. Also I think your article may be a bit out of date. Haven't there been more successful studies recently?

I certainly agree about how weak the "ground truth" really is when it comes to these diseases. The theories are necessarily always going to be highly simplistic models that are ultimately wrong but sometimes useful. The only real causation they can show is from studies which show a drug works. And even then they usually don't really understand why (though it's human nature to think that if you can predict something successfully your theory is proved to be true).