Certainly people with BPD often meet the criteria for other mental illnesses.
In the beginning with uBPDxw, I was aware that she had a history of anxiety and depression. Pretty "standard" stuff with regards to mental health issues, and something that seemed to be reasonably under control at the time. And of course, being a caregiver myself, I figured we could handle that together.
It was only about a year before I asked to separate that she had been additionally diagnosed with adult ADHD (impulsive manifestation). This was fourteen years into our relationship...after years of emotional outbursts and arguments. And no actual diagnosis of BPD, no matter how much I am convinced that it's there (and my T even supports it based on all everything I have told her--and shown her in forwarded emails, screenshots, etc).
To complicate it further, in the reading I have been doing lately I am learning more and more about the underlying narcissism inherent within BPD...the overlap in DSM-5 criteria and basic behaviors. I have seen it suggested that all pwBPD have some level of NPD (though not all with NPD have BPD).
I have struggled a bit with that because when I think of narcissism, I generally think of the malignant type. uBPDxw never fit that description. Sure, I had finally come to recognize how selfish she was, how only her needs really mattered, but there was never a maliciousness to what she did...nor did there even seem to be much awareness of that, or intent behind her abusive behavior. But I have been learning more lately about the covert narcissist, and the behavior of that group seems to align so much more with my uBPDxw's behavior.
So the really difficult knot to untie is how much of uBPDxw's behavior (or the behavior of any pwBPD) is one disorder vs. the other...or maybe it would be more accurate to say one
instead of the other. Ultimately, maybe it doesn't matter, but I guess it would be helpful to understand so that we can better understand the effects on us.
mw