From what I've read/seen, and take this with a grain off salt because I'm a layperson, amyloid beta is associated with things like Alzheimer's, but there are co

From what I've read/seen, and take this with a grain off salt because I'm a layperson, amyloid beta is associated with things like Alzheimer's, but there are counterexamples where people have a ton of amyloid beta and no pathology, and drugs targeting it have not been very successful so far. I think it's something that correlates with impairment, but it could be a side effect of or contribute to some other processes that are causative as opposed to being correlated with Alzheimer's/etc. More broadly, medicine seems to strong prefer testing for specific things and linking those to pathology instead of attributing pathology to things we can't detect or don't understand, so there's been much more research trying to affect things we can measure than trying to find/figure out things we could be missing/not understand.