Do you think that BIPS require that people tell them the truth more than "normal" folks? It's something I've wondered about for years. Ever since I was a kid, I've hated it when people lie to me. I would rather someone say, "I really can't be your friend any more," rather than ignoring me.
While being truthful is a quality I admire, it's not one I could always engage in. I used to think it was better to "walk away" than to tell someone something unpleasant. I used to find it impossibly difficult to say, "I have a problem with your behavior," or "I can't do that (whatever) because it's not consistent with my morals and values."
I believe I was able to change for two reasons. The first is therapy. While my therapist never diagnosed my illness, she did help me learn how to express my emotions honestly and openly.
The second is surviving 120 depressive episodes. During the worst of these periods, I felt like each time I "came back," it was if I had survived a death-like experience. After surviving enough of these, it finally seemed like I learned a series of lessons that have remained with me.
One is that life is too short to "lie" so I might as tell the truth. It might not make everyone else happy but it sure does wonders for me.