Your child was born insane and definitely didn't become insane as a result of severe isolation from society, bullying from all children and adults in their lives, and constant abuse at a school that literally grooms them into being dependent and incapable of defending themselves.

And the same disorder that made them insane, dependent, feral, and constantly overwhelmed made them sane, independent, and part of society when you finally gave them a chance at a real life. They're so strong because of the disorder that made them weak and easily overwhelmed. They're so smart because of the disorder that made them too stupid for regular school.