I saw a documentary about it as well, not sure what it was called though. It was about that UK nanny who got accused (possibly convicted I can’t remember now) of it based on one DRs testimony. He has since gone back on his diagnosis of it and now experts do not believe it actually exists.
It is terrible
. So many broken families because of it. I also saw another documentary about a DR who devised a drug and alcohol screening test using hair. So many children were taken away from their mothers based on this test over the years. Turns out it was a completely flawed test!