BPDFamily.com

The last girl I was dating, we decided to go the friends route back in October  (after she blocked me for a month). She's currently in the queue to be seen by the NHS here in the UK to see a specialist about potentially having BPD.    She definitely seems to have a lot of the symptoms - eg  fear of abandonment, anger, promiscuity, drug use, impulsive, projecting, very rare suicidal thoughts etc  Indeed our brief romantic relationship went from her telling me she was "smitten" with me, to there being "no spark" 10 days later.

However to me, she appears to have a strong sense of self, she doesn't seem to be changing her interests & beliefs from bf to bf.  She has strong political beliefs and insists any new bf share the same taste in music and party lifestyle she has.  So with this in mind could she still have BPD?  or more likely something that may appear similar such as PTSD from abandonment / relationship anxiety maybe?  

My guy is diagnosed with BPD (in addition to anxiety and depression) and definitely meets a lot of the criteria. But like your girl, he is very passionate about specific hobbies and interests and has a strong political opinion. All of that consistent over multiple years and independent of friends or love interests.

His self image and self worth are highly dependent on other people's reactions though and his perception of himself in this regard is highly fluctuating.

I think the DSM 5 criteria
 identity disturbance: markedly and persistently unstable self image or sense of self
does not necessarily only relate to erratic changes in likes and dislikes but also unusual inconsistencies in the perception of self in general.

Furthermore, it isn't obligatory for a valid diagnosis to present all symptoms listed. Self harm for example is a behavior that is often associated with BPD and is one of many diagnostic criteria. But there are some pwBPD who never self harmed but still fit the dignosis because they checked most of the other boxes.

Valid points. 

There is a quote in the autism community: "if you've met one person with autism,  you've met one person with autism."

Good question though. 

Dargumin   :hi:

It seems sometimes that someone has a strong sense of self when they take a strong stand on a particular interest, want, or opinion. So it's possible to have a very poor and unconsolidated sense of sense while still retaining very strong opinions about things. For example, an NPD is (also) thought to have a fragmented self, but may have that characteristic unshakeable opinion on their self-importance.

E.g., your ex similar to my ex had a belief that if her partner didn't share a taste in x music and y drinking style, then that person "was not meant for her".

For BPD I think the suggestions from Purplex and Turkish--to recognise that the sense of self is one of nine criteria--is a very helpful answer. For the second part of your question it might help to get a T's opinion as a supplement to answers you get here--plainly because each of these issues can get very complex. So thinking forward--if it's BPD, PTSD, or another anxiety-related disorder--does this have a consequence on your relationship life?

I can actually relate to this observation.  She found out what a couple of he ex's friends were saying about her and it made here extremely rageful and upset. It seems like she is very concerned what others think of her... .but then sometimes will behave in a manner which is sure to get people talking negatively.

She did exhibit some very black and white thinking the other day, she said she is totally unattracted to anyone from the area where she is born and currently lives (Liverpool, UK) and says this is why she always goes for long distance relationships (which make her miserable as I can tell).  Seems like a vicious circle.

You'll see the lack of self manifest as what looks to be a strong sense of self in a lot of ways. I'm not going to do this explanation justice but this lack of self is why you will see the BPD grab so tightly to certain groups or movements ie) anti-vaccine, parenting rules, political movements to the point of extremism.  But in my experience you'll also see blatant hypocrisy when it's convenient for them.

My exBPD was a health freak but only when it comes to food/household items.  Everything needed to be organic, washed with a special cleanser, hippie deodorant, soaps, cleaning agents.  
But then she was a chain smoker that refused to workout... .