"Borderpolar" is a Term, Not a Diagnosis

Mark Zimmerman, MD, director of the Partial Hospital Program and Outpatient Services at Rhode Island Hospital, discusses the term "borderpolar," originally brought to the Psych Congress audience in 2019, that refers to patients with both borderline personality disorder (BPD) and bipolar disorder. In part 1 of this video, Dr Zimmerman urges colleagues to recognize "the fundamental treatment of these 2 different disorders is quite different" and that "borderpolar" is a term, not a diagnosis. 

In part 2, Dr Zimmerman, who was recently featured in People discussing the term, dives into current research and research gaps surrounding "borderpolar."

Read the transcript: 

Meagan Thistle: Hi, Psych Congress Network family. I am Meagan Thistle, your Associate Digital Editor. Today we're sitting down with Dr Mark Zimmerman, and we will be discussing borderpolar. Dr Zimmerman, if you'd like to introduce yourself.

Dr Mark Zimmerman: Hello everyone. My name is Mark Zimmerman. I am director of the Partial Hospital Program and Outpatient Services at Rhode Island Hospital and professor of psychiatry and Human Behavior at Brown University.

Meagan Thistle: You coined the term "borderpolar" back in 2019 at Psych Congress. What led you to put a spotlight on this disorder specifically?

Dr Mark Zimmerman: Well, I'm glad you actually asked the question that way, Meagan, because borderpolar is not a diagnosis. It's a term. It's a term that refers to individuals who are diagnosed with both bipolar disorder and borderline personality disorder. The term came from a conversation I had with a colleague, who said that she was referring a patient to our Partial Hospital Program who had borderpolar, and I said, "What's that?" And she said, well, in her chat group, they refer to individuals with bipolar disorder and borderline personality disorder as having borderpolar. And I said, "Oh, I love that term." Because we have a lot of data here, "I'm going to write an article about that and talk about that," because I really think it's a very descriptive, concise term. A lot easier to say "borderpolar" than say "borderline personality disorder" and "bipolar disorder."

Thistle: So since your presentation, you've seen more patients being diagnosed with borderpolar. How would you go about treating this more effectively?

Dr Zimmerman: Many of the individuals that we see had not previously been diagnosed with borderline personality disorder. One of the reasons for bringing this topic for greater recognition is for a long time in the literature, there have been many articles published comparing individuals with borderline personality disorder and bipolar disorder, and there have been discussions of whether or not borderline personality disorder is a type of bipolar disorder. That debate has been pretty much resolved in favor of indicating that these are 2 different disorders. So while there is a fair amount of literature comparing individuals with each of these disorders, there's rather sparse literature looking at individuals with both.

We did a review of the literature a number of years ago and found that approximately 20% of individuals with bipolar disorder are also diagnosed with borderline personality disorder. And similarly, approximately 20% of individuals diagnosed with borderline personality disorder are also diagnosed with bipolar disorder. So this is not an either/or distinction, which is how it's often framed in the literature. Does a person have either bipolar disorder or borderline personality disorder? And we wanted to bring attention to the fact that there is a significant number of individuals who have both.

Now within our practice, it's much more common for individuals who are referred, particularly to our Partial Hospital Program, to have been previously diagnosed with bipolar disorder. And there's been a lack of recognition of the coexistence of borderline personality disorder. So I wouldn't say we're making the diagnosis any more than we made it before, but there hopefully is going to be ongoing recognition that it's possible for individuals to have both, and it's not a forced choice of one or the other.

Thistle: What work still needs to be done as far as educating other clinicians about borderpolar?

Dr Zimmerman: Well, certainly resources such as this is one way of educating individuals, that a subset of patients with 1 diagnosis also has the other diagnosis. We have written in the literature, and there is a fair amount of literature with respect to the underrecognition and underdiagnosis of bipolar disorder, that when someone comes in for the treatment of depression, it's very important for a clinician to inquire for and determine whether or not it's more appropriate to diagnose them with bipolar disorder, rather than major depressive disorder, because that has significant treatment implications. The use of mood stabilizer agents in individuals with bipolar disorder is the foundation of treatment for bipolar disorder, and you don't want to treat someone with bipolar disorder just with antidepressant medications because there's the risk of them flipping into a manic or hypomanic episode.

Much less has been written about the underrecognition and underdiagnosis of borderline personality disorder in general, and also with respect to individuals presenting for the treatment of depression. It's pretty rare. It's understandable why individuals with borderline personality disorder would have that under-recognized. Individuals present for treatment for their most salient symptoms, depression, anxiety, panic attacks. Individuals don't typically come for treatment and say, "I'm coming here because I don't have a sense of myself," or, "I feel empty inside," or, "I abandonment fears." That has to be elicited, and it can be elicited either by individuals telling their story and hearing their life story, or even very commonly by direct questioning, asking individuals about the diagnostic criteria for borderline personality disorder. But as I said, much less has been written about the underrecognition and underdiagnosis of bipolar disorder in comparison to writings, commentaries and research on the underdiagnosis of bipolar disorder.

Why is it important to recognize both? Because the fundamental treatment of these 2 different disorders is quite different. As I already alluded to, fundamental to the treatment of bipolar disorder is psycho-pharmacology. Individuals need to be on medication to treat bipolar disorder. In contrast, the core of treatment for borderline personality disorder is psychotherapy. There have been a number of psychotherapies that have been found to be effective for the treatment of borderline personality disorder, the most common being dialectical behavior therapy, or DBT, but there have been other psychotherapies, standardized psychotherapies that have been found to be empirically supported. So that's why it is necessary to recognize both when both are present.

Now to be sure, individuals with bipolar disorder are often appropriately treated with psychotherapy in addition to medication. And likewise, most individuals with borderline personality disorder are receiving pharmacotherapy. No medications, however, have been FDA approved or approved, in fact, anywhere in the world for the treatment of borderline personality disorder.

Nonetheless, the vast majority of individuals with borderline personality disorder are treated with medication because borderline personality disorder often coexists with medication responsive disorders, such as major depressive disorder, panic disorder, generalized anxiety disorder. But as I said, it's important to recognize both because the fundamental approach, the core approach towards treating each of these is so different. And therefore, it's necessary to utilize both medication and psychotherapy in treating individuals who have both borderline personality disorder and bipolar disorder.

Mark Zimmerman, MD, is a Professor of Psychiatry and Human Behavior at Brown University and director of the Partial Hospital Program and Outpatient Practice at Rhode Island Hospital. Dr Zimmerman is principal investigator of the Rhode Island Methods to Improve Diagnostic Assessment and Services (MIDAS) project. The MIDAS project has been ongoing for more than 25 years. The goal of the MIDAS project has been to integrate research methodology into routine clinical practice in order to improve clinical practice. 

Dr Zimmerman is the author of more than 450 articles published in peer-reviewed journals, and serves on the editorial board of 10 journals. He is the associate editor of the Journal of Personality Disorders. He has developed several measures of psychiatric disorders for use in clinical practice. He is the author of the Interview Guide to Diagnose DSM-5 Psychiatric Disorders and the Mental Status Examination.