Personality Disorders Support Group
Personality disorders form a class of mental disorders that are characterized by long-lasting rigid patterns of thought and behaviour. Personality disorders are seen by the American Psychiatric Association as an enduring pattern of inner experience and behavior that deviates markedly from the expectations of the culture of the individual who exhibits it.
I have BPD myself, and unfortunately only the person can answer it by checking out the DSM-IV, taking a look at the criteria, seeing if it fits their behavior, and seeing a professional.
Hope all goes well for you.
Remember to use "I feel this" and "that makes me feel" etc so things are less threatening in his mind. It is difficult but he will only learn in time with someones love and understanding how to understand himself and maybe slowly get better. Try not to give up. This sickness of the mind is lonesome enough on its own. Good luck