An expert perspective — grounded in clinical knowledge and lived experience with bipolar — clears up the confusion.
Trigger warning: this article contains a clinical discussion of suicide, which may be triggering to some readers.
Living with bipolar disorder is challenging, and the first hurdle is getting a correct diagnosis. In fact, there’s an average 8- to 10-year delay between when you start having bipolar symptoms and when you’re diagnosed.
Many people with bipolar have been misdiagnosed with a different psychiatric condition along their journey. One condition that bipolar sometimes gets confused with is borderline personality disorder.
At first glance, the two conditions seem to share some symptoms. But when you examine the specifics, it’s clear that bipolar disorder and borderline personality disorder are two distinct conditions. Let’s take a look.
Alphabet Soup: BD, BAD, BPD
Bipolar disorder and borderline personality disorder even get their acronyms confused.
Bipolar disorder is abbreviated as “BD” (bipolar disorder) or “BAD” (bipolar affective disorder) in research and clinical use. I personally don’t love reading that I have something BAD, so I use BD.
Borderline personality disorder is abbreviated as “BPD.”
For the sake of clarity, I’ll use “bipolar disorder” and “BPD” here.
Bipolar Disorder and Borderline Personality Disorder: The Basics
Bipolar disorder is a mental health condition that affects mood, energy, and behavior. Its key symptoms fall into two main buckets:
- Mania or hypomania: You may feel “up,” and like you have a surge of energy.
- Depression: You may feel sad, worthless, or guilty.
BPD is a mental health condition that primarily affects your sense of self and interpersonal relationships. Instability is a theme in BPD: It finds its way into relationships, sense of self, and moods. According to Cleveland Clinic, specific symptoms include:
- Fear of abandonment. You may do things to not be or feel abandoned.
- Intense and unstable relationships with others. You might view a person as either perfect or horrible, with little gray area in between.
- Unstable self-image or sense of self. You might view yourself as inherently bad.
- Feeling empty or alone. You may feel worthless or unfulfilled.
- Impulsivity. When you feel emotionally out of control, you may act quickly, without considering all the consequences.
- Self-harming or suicidal behavior. This can be actions or threats of actions.
- Mood instability. You experience frequent, sudden, and short-lived mood changes, often in reaction to something.
- Intense or hard-to-control anger. You may lose your temper or feel bitter and then feel shame or guilt about these feelings.
- Stress-induced periods of dissociation or experiences of paranoia. This can feel like losing touch with reality or feeling outside of your own body.
Why Are Bipolar And Borderline Sometimes Confused?
If you have bipolar disorder, some BPD symptoms may resonate with you.
As someone living with bipolar disorder, I have certainly experienced impulsivity with negative consequences during mania and emptiness during depression. But does that mean I have BPD, too? Not automatically.
Mental health diagnoses are based on symptoms, and many conditions have overlapping symptoms. For example, anxiety and ADHD share the symptom of difficulty concentrating. But no one would argue that they’re the same condition.
When two conditions have symptom overlap, like bipolar disorder and BPD, it can be hard to differentiate, especially if you’re not looking closely.
But the similarities between bipolar disorder and BPD are superficial, while the differences are profound, according to a scientific review comparing the two conditions.
Overlapping Symptoms and How Bipolar and Borderline Differ
Much of the confusion between bipolar disorder and BPD revolves around these three symptoms, which both conditions share:
How can you tell the bipolar disorder version of these symptoms from the BPD version? Look for patterns in:
- How often these symptoms happen
- How long they last
- What causes them
Mood Changes
Whether you have bipolar disorder or BPD, you may struggle with mood stability. In bipolar disorder, you may experience bigger highs and lows than neurotypical folks. With BPD, your range of moods is different. Although you may experience depression related to past traumatic experiences, you’re probably not going to have feelings of euphoria, increased self-esteem, or higher productivity like we experience in bipolar disorder. In BPD, mood shifts often feature anger or anxiety rather than feeling up or down. Timing and triggers of mood changes differ as well.
- Timing In bipolar disorder, mood changes come in episodes and usually last from a few days to months. Episodes will often have a start and end, even if those are gradual. In BPD, a hallmark feature is chronic mood instability. Moods in BPD change rapidly, sometimes within hours.
- Triggers In bipolar disorder, mood episodes may feel like they come out of nowhere, even though they’re often actually caused by life stressors or changes in sleep and circadian rhythms. In BPD, mood shifts often happen in response to a social interaction or perceived abandonment.
Impulsivity
You might feel impulsive with both bipolar disorder and BPD and end up acting on a sudden urge without thinking things through. Impulsivity, including reckless spending, unsafe sexual behaviors, and substance use, puts people with both conditions at risk for harm.
- Timing Impulsivity can be an ongoing problem in both bipolar disorder and BPD, according to a meta-analysis and another study on the conditions. But, in general, when you have bipolar disorder, you’ll notice increased impulsivity during mood episodes, including mania, hypomania, and mixed states. But with BPD, impulsivity may cause you problems in a more ongoing way. Like mood instability, it’s more chronic.
- Triggers In bipolar disorder, impulsivity most commonly flares as a result of mood episodes. I describe this as chasing the high, looking for the next hit of feel-good brain chemicals. It can also be a result of agitation, especially in mixed states. In BPD, impulsivity tends to be triggered by daily distresses, like relationship conflicts, according to McLean Hospital.
Suicidal Thoughts or Behaviors
Unfortunately, many of us with bipolar disorder have dealt with the urge to hurt ourselves or end our own lives. It’s an experience we share with those who have BPD. In bipolar disorder, the suicide rate is about 20 times higher than in the general population, according to a review of the research.
- Timing In bipolar disorder, suicidal behaviors and thoughts are most common during intense depressive episodes or dysphoric mixed states (the opposite of euphoric). Suicidal ideation can also occur during episodes of psychosis, such as when hearing commanding voices. In BPD, suicidal thoughts and behaviors can arise at any time, often unpredictably, though frequently during moments of intense emotional distress or crisis, especially following interpersonal conflicts or perceived rejection.
- Triggers In both bipolar disorder and BPD, suicidal thoughts often stem from overwhelming emotional pain and the false belief that there is no other escape. (Spoiler alert: There is — your brain is lying to you.)
Nonsuicidal self-injury (NSSI) refers to behaviors that cause physical harm — such as cutting, burning, or hitting oneself — without the intent to end one’s life. People engage in these behaviors as a way to cope with overwhelming emotions or to escape emotional pain.
- Timing In bipolar disorder, NSSI typically occurs during mood episodes. One study estimated that about 50 percent of people with bipolar have engaged in NSSI. In BPD, on the other hand, NSSI is common at any time, with some studies estimating an occurrence rate of 65 to 80 percent.
- Triggers For those with bipolar disorder, NSSI is often triggered by intense emotions tied directly to a mood episode. In BPD, the triggers usually involve interpersonal stress, which creates overwhelming emotional pain. In these cases, NSSI is thought to serve as a form of self-soothing.
Symptoms Come in Groups
Remember that to receive a mental health diagnosis, someone must have an entire cluster of specific symptoms. Having one symptom does not a diagnosis make.
Just because you are experiencing impulsivity and mood changes doesn’t mean you necessarily have either of these conditions. Every symptom needs to be seen in the context of what other symptoms it accompanies — and doesn’t.
That’s why it’s so important to speak to a mental health care professional, share all of your symptoms, and allow them to explore diagnoses with you. It takes an expert to diagnose bipolar disorder and BPD.
Different Conditions, Different Treatment Focus
Something else that differentiates bipolar disorder and BPD is the focus of the treatment plan.
Treatment for bipolar disorder, which has largely biological origins, usually revolves around psychiatric medications aimed at stabilizing brain function (notably mood stabilizers). As bipolar expert David Miklowitz, PhD, explains in this article, therapy for bipolar focuses primarily on symptom management and recognizing early warning signs. Lifestyle changes also play an important supporting role.
For BPD, the treatment plan’s balance is flipped. While psychiatric medication can help reduce symptoms of BPD, psychotherapy is the primary treatment. Some of the specific treatments can be the same for both conditions. For example, dialectical behavior therapy (DBT) is a therapy that was developed specifically to treat BPD. DBT skills are so useful, though, that the skills, like those to deal with intense feelings, have since been adapted for use in many other conditions, including bipolar.
Other Important Differences Between Bipolar Disorder and BPD
There are numerous additional distinctions between bipolar disorder and BPD — more than can be fully covered here. For example, these conditions likely have different primary causes. Bipolar has a strong genetic component and biological causes, with mood episodes often triggered by significant life events. In contrast, BPD is primarily a psychosocially induced condition, frequently (though not always) associated with adverse childhood experiences. Other key areas of difference include family history, response to medication, history of sexual abuse, and physiological brain characteristics.
Can You Have Both?
The short answer is yes. The long answer is that it depends. Experts disagree about how common this co-occurrence actually is and how much of that overlap is because of misdiagnosis.
About 20 percent of people with bipolar disorder also “meet the diagnostic criteria for comorbid BPD,” according to one review. The wording here is important: Each clinician can’t help but interpret diagnostic criteria differently, leading to disagreements and misdiagnosis. For example, it’s more common to be diagnosed with BPD when you have bipolar 2 disorder than bipolar 1 disorder. Bipolar is most easily identified when there are clear manic symptoms; clinicians may have a harder time diagnosing softer presentations of bipolar and, therefore, mistakenly confuse it with BPD.
Correct Diagnoses Lead to the Correct Care
As you’ve seen, some symptoms of bipolar disorder and BPD look similar on paper. However, when examined more closely, these symptoms manifest quite differently in real life.
No matter which condition you live with — bipolar disorder or BPD — there is treatment, and there is hope. But knowing which condition you have is essential to unlocking the correct care. That’s why diagnoses matter: Diagnostic labels serve as shortcuts for doctors and therapists to select the best treatment for you.
Always get a diagnosis from a qualified mental health professional (or maybe even more than one) to best address your needs and get connected with the best treatment for you.
If you or a loved one is experiencing significant distress or having thoughts about suicide and need support, call or text 988 to reach the 988 Suicide & Crisis Lifeline, available 24/7. If you need immediate help, call 911.
Editorial Sources and Fact-Checking
- Borderline Personality Disorder (BPD). Cleveland Clinic. May 20, 2022.
- Ghaemi SN et al. Bipolar or Borderline: A Clinical Overview. Acta Psychiatrica Scandinavica. February 26, 2014.
- Santana RP et al. Impulsivity in Bipolar Disorder: State or Trait? Brain Sciences. October 5, 2022.
- Everything You Need To Know About Borderline Personality Disorder. McLean Hospital. February 6, 2024.
- Tondo L et al. Prevention of Suicidal Behavior in Bipolar Disorder. Bipolar Disorders. October 9, 2020.
- Marc JW et al. Self-Harm, Affective Traits, and Psychosocial Functioning in Adults With Depressive and Bipolar Disorders. The Journal of Nervous and Mental Disease. November 2017.
- Brickman LJ et al. Borderline Personality Disorder and Emotion Dysregulation. September 25, 2014.
- Miklowitz DJ. Different Types of Therapy for Bipolar Disorder. National Alliance on Mental Illness. April 12, 2019.
- Temes CM et al. Comorbidity of Bipolar Disorder and Borderline Personality Disorder: Phenomenology, Course, and Treatment Considerations. Bipolar Disorders. July 21, 2024.
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