There is a LOT of causal data. Autopsies of brains of Alzheimer's patients were rife with amyloid. People with mutations that caused amyloid got Alzheimer's earlier than others.

The hypothesis didn't come from nowhere.

To contrast, look at how much trouble medicine has had treating brain tumors. It has taken a long time to get effective treatments for various reasons. And Alzheimer's is way less direct in cause/effect.

> Autopsies of brains of Alzheimer's patients were rife with amyloid

Do you want think carefully about how this can possibly suggest this is a causal link?

> People with mutations that caused amyloid got Alzheimer's earlier than others.

People with mutations in those genes got a particular type of inherited alzheimers early, this says nothing about the cause of general Alzheimers.

> People with mutations in those genes got a particular type of inherited alzheimers early, this says nothing about the cause of general Alzheimers.

This is completely analogous to claiming that people with mutations in BRCA (which causes a lot of early breast cancers) says nothing about general "cancer".

That's simply flat-out wrong. Genetic mutations like BRCA affect certain subsystems and many of those subsystems are common and relevant to many different cancers outside of breast cancer or breast cancers that appear later. Lots and lots of cancer research proceeded by studying the common systems that BRCA affects. Sure, those subsystems aren't involved in every cancer, but they're involved in a solid chunk of them.

And, even better, when you find one that isn't affected by one of those subsystems that BRCA touches, that's an interesting result, too. Now you can look at what the differences are, figure out what the new subsystems are and categorize your cancer more specifically which makes successful treatment more likely.

There is absolutely no reason to believe that Alzheimer's is any different on that front.

This comment is so needlessly aggressive and argumentative. I hate this about HN

It is sad. That reply, which you rightfully were irritated by, could have been expressed as a polite question.

That sort of question is what the response from user @bsder above helpfully tries to answer. That mode would invite more productive discussion, not more defensive annoyance.

Rules on HN say “Be kind. Don't be snarky. Converse curiously; don't cross-examine. Edit out swipes.” but it is hard.

All I can suggest is: be patient and try to be positive

It is also wrong...

Wouldn't mind knowing how.

It’s the way one talks to an LLM which has made a mistake.

Correlation is not causation but it's a pretty good idea to start with how blindingly obvious differences in brains affected with the disease might be related with the disease. There's also evidence that it precedes the symptoms of the disease.

And it's also not a good idea to suppose that you are dealing with unrelated effects without good reason. Mutations->more amyloid->earlier symptoms should be considered indicative of the disease pathway until sufficient evidence counteracts that, by Occam's razor.

Im not gonna try to correct you because its probably going to be futile, but I implore you to paste this thread into chatgpt and ask where you could be wrong in your logic.

Correlation not causation is all the more important in a topic like this; nothing you said suggests amyloid causes alzheimers or just forms because of it.

Just say your point instead of dancing around it.

What exactly do I need to say further? My first comment was that "scientists today still don't understand correlation =/= causation" and the replies are all scientists who try to explain again how correlation can still mean causation (no it doesn't, and it definitely doesn't in this case and that has been the root cause from the beginning). So I tried to implore you to go review your text yourself, but you are clearly above it, so not sure what else I could do here.

Research on the human body start with an observation, for the good reason that the omniscent orb has not invented yet, and what is causation and what is correlation is yet to be determined. Then, sometimes after years of research, it can be determined if what was observed was causation or correlation. That's why study that don't bring to a new discovery are extremely valuable nevertheless, as they show a path that was just a false lead and allow other researches to seek for something else

I would turn around the same request to you. I would ask that you look at how scientific research and hypotheses are actually created and the messy nature of evidence for anything that isn't particle physics and not just repeat cliches.

Ah causal data! It’s a shame none of the scientists or statisticians thought of getting causal data. How would we get that? Well maybe we could just inject amyloid into a person’s brain. Or simply remove all the amyloid from a person’s brain. That should do it, right?

I mean an amyloid injection is wildly unethical and it’s also not the natural progression of Alzheimer’s. Removing amyloid is a simple matter of investing billions of dollars into drug development. Also how do you tell whether that was actually “causal” if the patients improve after plaque removal.

I mean come on, you have to work the evidence and the experimental tools that we actually have. This kind of epistemic puritanism doesn’t help anyone.

> Well maybe we could just inject amyloid into a person’s brain.

Erm, we kinda did? People who got cadaver-derived human growth hormone from Alzheimer's patients got Alzheimer's.

https://www.nature.com/articles/s41591-023-02729-2

And we just had an actual autopsy confirm a case: https://www.medscape.com/viewarticle/new-evidence-strengthen...