Plays/Novels: Recs where one sibling abuses another due to a personality disorder-- then regrets it--?

Question

So any recommendations of a play or novel where one sibling that loves another dearly suffers from a personality disorder (such as mult. personality or bipolar or any other) where he/she abuses the sibling, then realizes what he/she is doing, regrets it, but it happens repeatedly.

Touching/emotional/tragic ending

any recs apprcd!

Answer 1

Try "Running with Scisssors" The book is messed up.