Anyone can learn to handle their emotions or situations differently. (That's what CBT is all about) It's just difficult to make them self-aware and motivate them to make the change.

I'm not sure people with personality disorders are aware of the way in which they interact with the world. It's so automatic and they've been doing it for so long. It's hard for anyone to recognize their own cognition and behavior. I think if someone with BP shows up in therapy it's because they've been disappointed by the effects of their disorder -- but they probably don't recognize that the problem is internal -- there's an external locus of control for them.

I know that therapists have a hard time helping patients who present with personality disorders because it's difficult to motivate them to change because they see their behavior as adaptive, not maladaptive. That's the big hurdle.