Here is the thing. The message from medicine has always been, "Well yes, there were problems in the past, but we do better now." And then they don't. A new round of problems shows up, gets a new round of criticism, a new round of, "things are better" happens, and the same old thing crops up. This pattern has literally held for centuries. Why should we believe them now?

Here are some examples. When I was growing up in the 1980s, we were taught ancient history like how much doctors resisted the idea of handwashing. Those who were curious could learn about the struggle to get double blind studies, and past disasters like the adoption of frontal lobotomies, or the development of hyper-radical mastectomies based on the theory that cancer spread slowly through tissues. (Breast cancer cells actually get metastasized through the blood.) I was so curious, and learned that we do better now.

Except that in the 1990s we found out that millions had had false memories implanted through bad therapy, and the idea of evidence based medicine became mainstream, clarifying how much better we didn't actually do in the 1980s. Under Bill Clinton we even briefly had a committee created to identify the most egregiously ineffective treatments to save costs. That committee's first recommendation was that except in obvious critical trauma cases, back surgery be a last resort to be tried after every other treatment option. The reason why was that it was the most expensive option, was the least likely to be effective, and long-term outcomes were worst.

Sadly, back surgeons were more effective at politics than at treating back pain. (They are also very profitable for hospitals.) Therefore that was also the committee's last report, and it sank without a trace. According to https://www.beckersspine.com/spine/item/45273-surgeons-perfo... reports we do roughlyt 1.6 million back surgeries per year, despite the fact that we have long had evidence indicating that we should do fewer of them. Let's state that a different way. Each year we spend billions of dollars on making the lives of over a million people worse because there is no willingness to act on data that has been available for decades.

THAT is the state of modern medicine.

Oh, and the much hyped move towards evidence based medicine? Every doctor will tell you that we now engage in evidence based medicine, the bad old days are gone. But estimates are that only half of medical procedures that we do have evidence of effectiveness. See https://www.vox.com/the-big-idea/2017/12/28/16823266/medical... for a popular article on that. It also shows that back surgeons have a lot of company. I guess things are better. We have some idea of how much current medical practice is useless..we just aren't doing anything about it.

Now do you see why I don't accept that things have fundamentally gotten better?

Now back to Alzheimer's.

Until less than 3 years ago, the field was openly hostile to research and researchers that didn't accept the amyloid hypothesis. This changed not because the field internally realized that it was doing anything wrong, but because of criticism received from outside the field. In Nature no less. So despite their theoretical awareness of how to do science, they failed to connect that to their own practice.

How many other fields are making similar mistakes but simply haven't been called out on it? My best estimate is, "A lot."

And yes, I did overstate my case in the passage you quoted. A more accurate statement is, "The unquestioned dominance of the amyloid beta hypothesis is the result of a failure to understand that correlation does not imply causation." As I have said repeatedly, there was nothing bad about following up on lines of evidence suggesting that amyloid beta was a good lead. The problem was rejecting all research into ideas that might question the favorite theory.

You know some other examples of where medicine went astray because people involved in a field rejected research into ideas that might question practitioners favored theory? Let's see. Frontal lobotomies, radical mastectomies, repressed memory therapy, back surgery, knee surgery, and so on.

At what point in this list should we start to suspect that there might be a pattern?