Do BPD and ParanoidPD go hand in hand?

[How to communicate after a contentious divorce...]

Curious because although there were definitely signs of BPD with my ex, I am certain that she had Paranoid Personality Disorder. In researching both, I learned that many symptoms are similar, such as "splitting" mistrust of others, extreme inability to handle criticism, and a constant suspicion of a romantic partner. My ex definitely exhibited signs of both, and she even admitted to me some very unusual suspicions - she thought I was going to kill her on a camping trip; thought I was taking advantage of her when she had to pay for dinner; asked me to tell her I was not with a prostitute one night when I stayed home and fell asleep on the couch before calling her (her father and ex husband saw prostitutes, she said). She admitted these things to me freely, but never actually said that she had PPD, but I do understand that people with this condition don't know it, or won't admit it. The last two weeks before our break up, her suspicions started becoming more irrational - "why didn't offer to carry the grocery bags when she was carrying them;" "why didn't get my daughter something to eat when she said she was hungry?" my daughter is 20 y.o.; "why did I choose to wash my truck on this day and not another day?" "why didn't I sit down and work on my lesson plans when I said I was and instead procrastinated for a day?" Very obsessive monitoring and hyper-fault finding which are common to BPD and PPD.

Again, she had an extremely traumatic and abusive childhood and marriage.

[rob66]

Curious because although there were definitely signs of BPD with my ex, I am certain that she had Paranoid Personality Disorder. In researching both, I learned that many symptoms are similar, such as "splitting" mistrust of others, extreme inability to handle criticism, and a constant suspicion of a romantic partner. My ex definitely exhibited signs of both, and she even admitted to me some very unusual suspicions - she thought I was going to kill her on a camping trip; thought I was taking advantage of her when she had to pay for dinner; asked me to tell her I was not with a prostitute one night when I stayed home and fell asleep on the couch before calling her (her father and ex husband saw prostitutes, she said). She admitted these things to me freely, but never actually said that she had PPD, but I do understand that people with this condition don't know it, or won't admit it. The last two weeks before our break up, her suspicions started becoming more irrational - "why didn't offer to carry the grocery bags when she was carrying them;" "why didn't get my daughter something to eat when she said she was hungry?" my daughter is 20 y.o.; "why did I choose to wash my truck on this day and not another day?" "why didn't I sit down and work on my lesson plans when I said I was and instead procrastinated for a day?" Very obsessive monitoring and hyper-fault finding which are common to BPD and PPD.

Again, she had an extremely traumatic and abusive childhood and marriage.

[Couper]

I can't answer your specific question with respect to the disorder you mention, but these kinds of backhanded accusations are one of the things that has me at the end of my rope. 

One of the things I thought I was going to see under this post was paranoia related to things societally.  My uBPDw now brags on some of her social media accounts that she was a conspiracy theorist 30 years ago.  When we were dating she explicitly told me she hated that her parents were gullible followers of conspiracies and that she couldn't tolerate the same in me if that was the case (it is not).  She was either lying back then or has done a 180.  It's such a huge disappointment to be regularly hammered with the kinds of questions (accusations) that you mentioned above.  There is no trust here and I've only ever been a solid citizen, but some cyber weirdo can come along with the latest absurd thing and it's red meat for her that allows her to either fuel her paranoia or perpetuate her victim status (or both). 

You might also look at these questions through the lens of her own self-loathing.  That old adage that when you point your finger you have three pointing back at you -- at the root of many of my uBPDw's accusations is she is really talking about something she thinks or did that she cannot stand about herself.  Shortly after we were married I caught her using the shower curtain rod as a grab bar and told her that rod is just spring loaded -- not mechanically fastened to the wall.  If she needs a grab bar, let me talk to the landlord and see if he would allow me to install one because someday that rod is going to pop out and she is going to break her neck.  She shot back that I didn't want her using it because I wanted to see her fall and break her neck because I hate her.  I told her, "If that's what I wanted, I'd just keep my mouth shut and wait for it to happen".  That was one of the first of many such emotional wounds.  Ten years later I learned that the root of it is probably her own self-loathing, but after over a decade of this I find it impossible to look at her with affection, especially since she has admitted in the past that she knows she says hurtful things with the intent of hurting people, yet she never apologizes for them.