Good question,

First, it is important to note that there IS a difference (according to the Diagnostic and Statistical Manual) between paranoia in Borderline Personality Disorder, compared to psychotic illnesses like Schizophrenia, Bipolar Disorder, etc. I do not know word for word what the difference is, however, I do know that there is a spectrum - just like all things - where on one side psychosis can be considered "Borderline psychosis," whereas on the other side psychosis can be considered, "Schizophrenia level psychosis."

This is what you wrote: "transient, stress-related paranoid ideation or severe dissociative symptoms"

To simplify, breaking this series of words into smaller constituent parts may help put sense into the phrase as a whole - in relation to Borderline Personality Disorder.

To clarify: (These are my own educated definitions, NOT FACTUAL, nor directly from DSM)

1.) ((Transient)) = means temporary

2.) ((Stress-related)) = means correlated to stress levels
EX: When stress increases, our level of resilience decreases - and thus, we can and do believe the negative thoughts that can and do arise with Borderline Personality Disorder.

3.) ((Paranoid ideation)) = means paranoid thoughts can and do arise
EX: Typically one thought leads to another, and our anxiety leads us to think more and more about that which troubles us most, (fears of abandonment) and then we conclude something is FACT when really: our anxiety only leads us to believe our worst fears are coming true... (That which we fear the most comes true: to us, despite (in most cases, but not all) all evidence for the contrary)

4.) ((Severe Dissociative Symptoms)) = means potential for loss of reality, out of body experiences, severe anxiety induced spiral, loss of identity, etc

In terms of Borderline Personality Disorder, psychosis is not fully recognized as a primary symptom in and of itself. (Being that psychosis is typically considered a "Loss with Reality.") Typically, any psychotic symptoms experienced by a Borderline - pertain specifically to the (ROOTS) of all Borderline issues: Abandonment, Relationship issues, imagined loneliness, etc. Whereas, with strictly psychotic illnesses, such as Bipolar Disorder or Schizoaffective Disorder - the psychotic symptoms experienced pertain to anything and everything, and can happen without any external situation or motivation. It can have themes of any subject, with or without any correlation to deep-rooted psychological issues, whereas with Borderline - any or all psychotic symptoms that may arise - almost always will have Borderline themes and roots.

That being said, it is fair to say that any form of Borderline "psychosis," is purely logical - given that they almost always correlate to their worst fears... Which brings into light the difference between Psychotic illnesses, vs Borderline psychosis: in that - Borderline psychosis is in line with logical fears, whether they are real or imagined, whereas, with Psychotic illnesses: psychosis is purely illogical and typically themed randomly and without logical consequence / justification.

That is not to say that Borderline Personality Disorder is no worse. One could in fact say the opposite - that Borderline psychosis is worse because it is quite literally their worst fear coming true. Borderline psychotic symptoms, (such as intensified fears of abandonment and relationship anxieties) - can and do become real to those with Borderline. Sometimes these thoughts are truly justified, but most times they are not. We with Borderline come to realize that all our paranoid thoughts stem from fears of abandonment, and almost always - those fears are only exacerbated by our increasing stress levels and decreased levels of emotional regulation and ability to remain resilient while in times of stress. (Hence: "transient, stress-related paranoid ideation or severe dissociative symptoms")

Almost always, those fears of abandonment, no matter how real they are - are actually false, but our fears are driven from our past experience of actually having been abandoned in some way, (conscious or unconscious) and thus we logically come to the conclusion that we are being abandoned again. This is ultimately the scar that us Borderline's share with one another, however, we (unlike fully psychotic individuals) are typically, able to regain quick awareness of our tendency to over-think things, and attribute our worst fears to everyday happenstance. Thus, learning to remain present, aware of our thoughts, aware of our patterns inside our mind and in our relating with the outside world and in relationships with others - we can truly learn to take control of our lives and prevent ourselves from reaching any kind of paranoid ideation.

Just because someone doesn't reply to our texts or phone calls when we expect them to, doesn't necessarily mean they don't like us. Just because someone doesn't want to see or talk to you for a few days doesn't mean they don't like you. Just because someone you know did not take time to look you in the eye while passing in the hallway, does not mean they hate you. Just because you can't find a partner who will stay with you longer than a week, doesn't mean they don't like you. BUT - it is easy to see why we with Borderline would come to think so... It is logical to us... This is arguably the difference between Borderline psychosis, and full on psychotic episodes, and I hope it has helped you to understand more about it.

Thanks,
HD7970GHz