I just recently read two fics about harry with brain damage and autism.
Session Transcripts by lastcrazyhorn
What happens when a brain damaged Harry and a transgender Hermione both get sorted into Slytherin? Snape's not sure, but he thinks it's likely to be an interesting term. This story follows various first years through the trials of their first year.
Different, Not Defective by awesomelyglorious
Everyone said Harry was different, but what if the differences were more than just surviving the killing curse? What if Harry had Autism? How would the wizarding world react and adapt to The Boy Who Lived?
I want to know if there are any more fics like these. Both are Snape becomes a mentor fics and that is what I really want but anything with Harry with some kind of mental problem (either because of the killing curse or not) that makes him act childlike would be great.