A therapist's perspective
I've just come across an old (2013) article that describes a therapist's perspective on borderline personality disorder. I suppose it was really written for therapists, and of course it is only one point of view, but I found it informative. As you might expect, it mentions some very upsetting things.
Therapists typically dread these clients since they can be among their most difficult, unpredictable, and unnerving.
But the overall message to therapists is very positive:
These clients deserve to be in relationship with someone who, after initially being triggered, can regain perspective and see behind the explosive rage, icy withdrawal, or manipulative controlling to the pain that drives those behaviors. As you become aware...[and] let your inner self shine through, not only will these difficult clients become some of your most rewarding, but your level of self-leadership and compassionate presence will increase.
Listeners might also be interested in the fragments of dialogue, because I think they are good examples of active listening.
See: Depathologizing The Borderline Client
Charlie