I have a friend who's dating someone with some pretty deep issues in the antisocial/narcisism/depression area. She keeps waiting for her SO to "go back to normal." I've honestly come to believe that some disorders are more about behavior compulsions than static types. I think people come with natural inclinations toward certain needs i.e. some people really enjoy social attention and some need it less. I think these basic needs become problematic (maladaptive, disruptive whatever) when they find negative outlets.
So my friend's SO likes to say REALLY abusive things to get attention. It's a basic need for attention that just has a problematic outlet. It works so she keeps choosing to use it. There's underlying history that leads her to use that outlet but I don't think the abusive part is a personality thing. The attention is, if that makes sense.