Splitting is an unconscious process and one of the primitive defence mechanisms described by Freud. In patients with EUPD there is recognised to be a tendency to idealise or denigrate others in relationships (including professionals), ie no grey areas - also, this can oscillate (there is a book written by someone with EUPD called ‘I love you, I hate you, please don’t leave me’ which kind of sums this up).
Splitting in teams is well recognised, it is something which is not carried out consciously by the patients, but kind of reflects the internal process of idealisation/ denigration. Some staff may feel sorry for patient, maternal, wanting to save them, others will be more skeptical/ dismissive/ see manipulation etc. This is closely tied to the triangle of relationships consisting of abused, abuser and saviour, which are roles people who have suffered trauma and abuse often end up playing out in future relationships, including with professionals.
So in summary, patients do not deliberately split teams, it’s an unconscious dynamic which occurs. The word ‘manipulative’ does get used, I think people use it less now, although they may think it. It’s less acceptable to say - but the word ‘behavioural’ is used often, which is pretty meaningless as everything is behaviour. I teach medical students about EUPD, and we frame self harm / suicide attempts as communication of distress, not manipulation. We also teach about stigma and try to break this down, in part by involving peer workers in teaching.
You would not be diagnosed with EUPD by your GP. It really is not common to be misdiagnosed when the actual diagnosis is bipolar disorder -more often people with ‘bipolar disorder’ are subsequently rediagnosed with EUPD.
The one thing that I have noticed recently is, particularly women, with EUPD diagnoses being recognised as having autistic features and sometimes this leads to rediagnosis. It’s a small proportion though.