Paranoia personality disorder

Can anyone shed some light on this?
My friend has lost almost all of her friendships. She has been diagnosed with depression, however I believe she has paranoia personality disorder because depression doesn't seem to match and paranoia pd adds up. She uses her depression diagnoses to blame for everything she does. She won't listen, she can't see that she is overrracting, gets sad when people don't do what she wants or gets what she wants, she expects her friends to be there for her regardless how she shit she treats them time after time. It's manipulative and selfish.
I don't know how to help.
I feel I can only step away and let her figure things out, even if she decides I'm not a real friend if I do.