short version the name was changed because its a dissociative (feeling numb, feeling spaced out, feeling disconnected... ) disorder not a personality (behaviors ie acting paranoid, avoidance, getting into fights with relationships .......) disorder.

personality disorders focus on one area of a persons life where as dissociative disorders affect all aspects of a persons life.

neither personality disorders nor dissociative disorders (with the exception of DID here in america) requires a person to be traumatized or abused. that said ........Some..... who have been diagnosed one or the other or both have gone through trauma or abuse.

hope that has helped.