The author could have just as easily written "Cancer, as currently defined, does not exist" or "Arthritis, as currently defined, does not exist". In all of the

The author could have just as easily written "Cancer, as currently defined, does not exist" or "Arthritis, as currently defined, does not exist". In all of these cases, the the catch-all phrase is used to describe a handful of similar symptoms that stem from a wild variety of causes. This is why we won't be curing cancer any time soon. We may cure a specific type of cancer, but we're going to have to cure each type of cancer in a specific a relevant way. If the author wanted to say "ADHD is actually a catch-all term for a variety of root causes that would be better treated with specificity" I would be all over that. But, hey, page views.