There is:
Book
A life in pieces .. written on Karen Overhill by Richard K Baer ?
Movies
Identity
Hide and Seek
Though i think MPD and DID is different to one another.. no?
Like MPD you can only develop that prior your personality fully developing at age 7 approx
But DID people can develop that when they experience trauma/ nervous breakdown and then the subconscious starts to split using memories of their past and you know giving them an *other* to help them with daily life, needs.... and after the personality fully develops ?
But who knows i'm no expert, sorry for this slight bit of whatever i just said

(just trying to clarify confusing concepts, don't mind me