What Does it Mean to Be Borderpolar?

“I feel like, to have both, it’s very painful,” said Sally (a pseudonym), who explained that her bipolar disorder was triggered by taking antidepressants, whereas her borderline personality disorder resulted from being physically abused as a child. “You can really fully recover from borderline, but for sure, bipolar, I never see going away.”

Borderline personality disorder is such a problematic diagnosis that critics argue that it should be abandoned altogether, and not just because it is stigmatized. It pathologizes victims of trauma (especially women), its heterogeneous symptoms are not personality traits, and they overlap considerably with several other disorders, including bipolar.

Nonetheless, most psychiatrists have converged on the view that it is possible for a person to simultaneously have bipolar disorder and borderline personality disorder, a phenomenon referred to in shorthand as “borderpolar,” although this is not an official DSM diagnosis. According to Dr. Mark Zimmerman, one in five people with one condition also has the other. Based on prevalence estimates of bipolar and borderline, this implies that almost 2.5 million people of the 334 million people in the United States in 2023 are (or will become) borderpolar.

What does it mean for an individual to have borderpolar? Borderpolar has multiple meanings that do not necessarily co-occur: a person may meet DSM-5 criteria for bipolar and borderline, be diagnosed with both disorders, identify with both, one, the other, or neither, and be treated by other people as if one is borderpolar (or not). Owing to the imperfect reliability and validity of the constructs, clinician diagnostic biases, human autonomy to identify with or reject psychiatric diagnoses, and the tendency to mistreat people who are perceived as being mentally ill, a person could be diagnosed with both yet only identify with one while not strictly meeting criteria for either, all the while facing daily discrimination, among myriad other possibilities.

The DSM-5 contains detailed criteria for bipolar and borderline, but how they are assessed depends on which instrument is used, and who is using it. The standardized questions in psychiatric epidemiological surveys of the public produce relatively reliable data. However, the data have questionable validity because they are based on a snapshot of a person’s state that does not consider precipitating circumstances that might explain why someone appears to meet criteria for a disorder on a given day. Standardized clinical assessments are reliable and may be more valid when carried out by mental health professionals who take seriously the possibility of alternative explanations, but they are limited to people in treatment for their mental health. There is no definitive test of whether an individual has either condition owing to the absence of disorder-specific biomarkers, and considerable overlap between bipolar and borderline (as well as major depression and schizophrenia) found in genome-wide association studies of people who ostensibly suffer from one or the other.

According to Dr. Joel Paris, psychiatrists tend to favor giving a diagnosis of bipolar over borderline because they are more familiar with bipolar, it is less stigmatizing to them, and its first-line treatment (psychopharmaceuticals) is in their toolbox. By extension, some psychologists may favor diagnosing borderline over bipolar since there are no FDA-approved medications for it (which psychologists do not prescribe), and its first-line treatment—psychotherapy—is their strong suit. Given diagnostic biases and between-specialty predilections, different mental health professionals can make conflicting diagnoses, a disconcerting prospect for people trying to make sense of themselves and their suffering.

Imagine what a person might do when told they have bipolar and borderline. A quick google search would direct them to consumer mental health information sites, like those of NIMH, the Mayo Clinic, or NAMI. Upon reviewing them, they might be surprised by how many symptoms overlap between the two disorders, yet how differently they are described. Both are characterized by mood instability, impulsivity, intense anger, suicidality, transient paranoia, and unstable relationships yet, according to these sources, bipolar supposedly originates in the structure of the brain, whereas borderline, we are told, evolves from the faulty development of the personality. Alarmed by the gravity of their apparent fate and left with many questions unanswered by the clinician who diagnosed them, the individual understandably might turn to another kind of expert for more information – people with lived experience.

Open-source social media sites for people diagnosed with bipolar or borderline are replete with borderpolars’ expressions of dissatisfaction with their clinicians.  Rather than relying on professional expertise, they reach out to hundreds of thousands of similarly situated strangers in online forums to express their doubt and frustration. Take, for example, a person who wrote on Reddit: “I’m starting to doubt if mental illness is even real,” followed by “One of my earlier doctors diagnosed me with bipolar disorder, and my current one has diagnosed me with borderline personality disorder. What are the differences between the two, because I’m seriously confused?”

Confusion surrounding one’s diagnosis is problematic in and of itself, but what about being misdiagnosed? One study found that people who met criteria for borderline tend to be wrongly diagnosed with bipolar. What might be the consequences of being diagnosed with bipolar when borderline is the better fit? For some people, first-line treatments for bipolar such as lithium or anti-psychotics mark the difference between being totally disabled versus able to function, but many people also experience serious adverse effects from the drugs. Psychological numbing, excessive sleepiness, mental confusion, and the tendency to become dangerously overweight top the list, as well as tardive dyskinesia and other movement disorders caused by taking antipsychotics. None of these harms are compatible with flourishing, especially for people who would benefit more from intensive psychotherapy.

Access to intensive psychotherapy, however, is not an automatic outcome of receiving a borderline diagnosis. A more likely result is to be disdained and dismissed by mental health care providers who have more negative attitudes towards borderline personality disorder and the people diagnosed with it than they have towards any other psychiatric diagnosis.

When a person’s presenting symptoms could fit into either the borderline or bipolar diagnosis, some psychiatrists lean towards diagnosing bipolar because they fear that withholding psychopharmacological treatment from a person who might be in a manic episode could allow mania to surge unchecked, landing them in a psychiatric hospital, or worse yet, in jail, putting the psychiatrist in legal jeopardy for misdiagnosis. No mental health professional wants to feel responsible or be held liable for these consequences, but consider this: who wants to be wrongly diagnosed and mistreated for the sake of protecting mental health professionals? Sadly, victims of this outcome have far less power to determine their diagnosis than do their clinicians.

Very little is known about people diagnosed with borderpolar, let alone misdiagnosed with either bipolar or borderline. Faced with this knowledge gap and motivated by my own odyssey of receiving a variety of psychiatric diagnoses over my adult life, none of which ever fit, I have embarked on a study of people who know themselves to have been diagnosed with bipolar and borderline, beginning with a standardized survey of them. Thus far, I have gathered survey data from 65 people, mostly recruited on Prolific Academic, interviewed a subset of them in-depth to follow up on their survey responses, and am analyzing the interview transcripts using flexible coding.

I started the survey by asking when they were diagnosed, and what they thought of their diagnoses. As you might expect, fewer than half got both diagnoses from the same clinician (reflecting their unreliability), and most were diagnosed with bipolar first. However, personal opinions about the accuracy of their diagnoses diverge considerably. Fifty-one percent agreed with both, 19% agreed with bipolar but not borderline, 20% agreed with borderline but not bipolar, and 11% did not agree with either diagnosis. During the in-depth interviews, I probed for further information to better understand why they identified with both, one and not the other, or neither, and how it related to their explanatory models and responses to treatment.

The reputation of “borderlines” is well-known to those who identify with bipolar and not borderline, like Jessica. She was diagnosed with bipolar at age 20, and borderline at age 25: “I just remember thinking, yeah this [borderline] might fit me, but it might be kind of like astrology, like a self-fulfilling prophecy,” she said, skeptically. After a few years of toying with the idea, she decided she did not have borderline because “I’m not that crappy of a person!” Medications had kept her manic behavior at bay for 30 years, but nothing alleviated her depression. She felt tired all the time and was resigned to it as her fate “unless somebody has a major breakthrough.” As for why she had bipolar, no traumatic events came to mind, so she attributed it to “bad genes, I guess.”

Cassandra, in contrast, rejected bipolar and embraced her more recent diagnosis of borderline personality disorder because it made perfect sense to her: “I didn’t really get to develop a personality, because I was always so focused on survival, getting beat and raped and sexually abused. Those are the worst kind of situations to try to develop your personality in.” Apparently unaware of how stigmatized borderline is among mental health professionals, or of  its long and controversial history, Cassandra viewed it as a positive development in psychiatry, assuming they “didn’t know anything about BPD 15 years ago” when she first was treated for bipolar and “doped up on Seroquel.” For her, taking medications might benefit the people around her by mollifying her, but they left her feeling “like a shell, like I am in there somewhere, but I can’t find me.” Fortunately, a compassionate psychotherapist was finally teaching her the “right tools” to deal with her problems.

While most people diagnosed with borderpolar assented to both diagnoses, they did not necessarily view them as central to their identity, let alone adhere to their prescribed treatment. Keisha, for example, did not argue with psychiatry, assuming her dual diagnoses were probably correct because she came from “crappy genetics and a crappy environment.” However, she did have a problem with her doctor’s recommendations because the bipolar medications “make you dim and not feel anything at all,” which was incompatible with her professional career. Instead, she managed without taking any medications, although it was “messy.”

Those few individuals who rejected both diagnoses were adamant that the mental health professionals got them “all wrong.” Considering the stigma and severity of each condition, I expected more people would reject one or even both diagnoses. Perhaps what appears to me as acquiescence reflects the real benefits of being diagnosed and treated. Moreover, those who self-selected into completing a survey on borderpolar may be more likely to agree with their diagnoses.

However, I suspect that most people with borderpolar have more pressing problems on their minds than challenging their diagnoses. Based on my analyses of nationally representative data of people who meet symptom criteria for bipolar and borderline, those with the borderpolar diagnosis tend to be at a profound disadvantage compared to those with only one or neither condition. Experientially, they have endured greater exposure to adverse childhood events like sexual abuse, and to adult trauma like being assaulted by a romantic partner. Physically, they have worse overall health and more ill health conditions. Socioeconomically, they are less educated and have lower incomes. Many, no doubt, have been stigmatized.

Ideally, having borderpolar would mean immediate access to the best mental health care available, justifiable hope for recovery, and the opportunity to realize one’s full potential in this life. Realistically, I have yet to find anyone describe the consequences of their dual diagnosis in these terms.

While psychiatrists continue debating and developing their descriptions of disorders, untold numbers of individuals are grappling with this controversial condition. Branding them as “borderpolar” may roll off the tongue more easily than having to spell out bipolar disorder and borderline personality disorder, but what that catchy term obscures are individuals, each with a distinctive, compelling, and remarkable life history that is beyond categorization.