While I believe there are many cases of these as well as other illnesses that are real, I think many times they are a creation of a mothers or teachers imagination.
There certainly are whacky moms and whacky teachers (whacky dads too), but it’s difficult to “fake” test results and to get a bunch of doctors and therapists to go along with it.
I’m not saying it doesn’t ever happen, but I doubt it is a very large number.
If many of these parents didn’t seek help for their troubled children - they would also be accused of negligence and neglect.
Either way - parents can’t seem to win in the eyes of certain people.