It’s so tough. We thought we had plenty of supports in place for our son - my husband flew down to Texas with him at the beginning of his sophomore year. They had meetings with his advisor, professors, dorm, doctors, etc. But within a week, he was in such bad shape he had to fly home (the doctor was being literal when she said “the next plane”). Looking back, we were in a bit of denial. We couldn’t accept the fact that our highly-accomplished son could fall so seriously ill so quickly. In hindsight, we should have brought him over after his freshman year. 
And now I see other parents frequently making the same mistake. If I know them personally, I try to persuade them to see things realistically, but I’m usually not successful.