Borderline Personality Disorder vs Bipolar

Arthur Mead
Author: Arthur Mead Medical Reviewer: Dr. Jenni Jacobsen, PhD Last updated:

Borderline personality disorder (BPD) and bipolar disorder are often confused as they share many similar symptoms, such as mood instability and impulsive behavior. However, they are distinct conditions that require different treatment plans.

What does borderline personality disorder look like?

Borderline personality disorder (BPD) is a chronic psychiatric disorder characterized by pervasive affective instability, self-image disturbances, impulsivity, marked suicidality, and unstable interpersonal relationships. [1] BPD is also characterized by mood changes (called emotional dysregulation or affective instability). Mood changes in patients with BPD are often instantaneous, going from feeling good to being very distressed within minutes.

According to the Diagnostic and Statistical Manual of Mental Disorders (DSM), the symptoms exhibited by people with BPD are:

  • Fear of abandonment
  • Unstable and intense relationships
  • Identity disorder
  • Impulsivity (spending money, sexuality, substance abuse, other kinds of risky behavior)
  • Recurrent suicidal behavior, threat of committing suicide or self-injurious behavior
  • Emotional instability
  • Feelings of emptiness
  • Inappropriate anger, uncontrolled aggression
  • Stress-dependent paranoid ideation or dissociative symptoms. [2]

The cause of BPD is not known, and it is suggested that BPD is the product of an interaction between genetic, neurobiological, and psychological influences that affect brain development. [1]

What does bipolar disorder look like?

Patients with bipolar disorder experience recurrent episodes of pathologic mood states, characterized by depressive or manic symptoms, which are interspersed by periods of relatively normal mood. [3] Mood shifts in bipolar patients often go from depression (persistent feeling of sadness or loss of interest) to mania (periods of euphoria, delusions, or hyperactivity) or hypomania (a less severe episode of mania). The duration of mood episodes is highly variable, both between patients and in an individual patient over time, but, in general, a hypomanic episode may last days to weeks, a manic episode lasts weeks to months, and a depressive episode may last months to years. [3]

During periods of mania, symptoms include:

  • Racing thoughts
  • Hyperactivity
  • Overly happy, angry or irritated mood
  • Reduced need for sleep
  • Impulsivity (substance abuse, sex etc.)
  • Making big plans
  • Reckless or risky behavior

According to research, risk factors for bipolar disorder are numerous, both genetic and environmental; however, some findings are inconsistent. Due to inconsistent findings, difficulty identifying whether risk factors cause bipolar disorder or are a result of the condition, and lack of a specific biological cause of the condition, it is difficult to determine what causes bipolar disorder to develop in a particular patient. [4]

BPD vs bipolar disorder

Bipolar disorder and BPD are among the most prevalent and frequently diagnosed psychiatric conditions. Both are associated with increased morbidity, elevated rates of suicide, and considerable functional impairment. [5] Another area where they share similarities is their causes, both being thought to be caused by a variation of genetics, environmental factors (trauma, stress, and childhood abuse) and brain differences.

Despite some similarities, the two conditions can be distinguished in several ways:

  • Bipolar disorder tends to involve alternating periods of mania and depression, whereas BPD usually involves intense feelings of unpleasant emotions such as emptiness, desperation, anger, hopelessness, and loneliness.
  • Mood changes in BPD tend to be shorter, sometimes only lasting for a few hours, whereas they can last for days or even weeks in the case of bipolar disorder.
  • Mood shifts in BPD usually have some sort of a trigger, such as an argument with a loved one, while mood shifts in bipolar disorder can happen quite suddenly without any trigger.
  • BPD mood shifts don’t tend to involve euphoria, and instead involve going from feeling bad to feeling alright. Bipolar disorder mood shifts, however, involve going from feeling bad to an elevated mood.

While the concept of bipolar disorder has, over the past several years, been fully incorporated by culture, most of the general public is not yet completely familiar with the diagnosis of BPD, despite its popularity among psychiatrists and mental health providers. [5]

How are they diagnosed?

In order to diagnose BPD or bipolar disorder, a mental health professional will ask the patient about their symptoms, asking them to describe their severity and duration. They will also ask about any family history of mental illness and about any history of trauma.

There are cases where it is difficult to distinguish BPD from bipolar disorder, and so the mental health professional may wish to focus on specific symptoms. These include:

  • Sleep: People with bipolar disorder have very irregular sleep cycles, especially during periods of depression and mania. This is not a symptom of BPD, and patients with BPD have normal sleep cycles.
  • Mood cycles: Bipolar disorder mood cycles tend to last longer (weeks to months) than BPD mood cycles (hours to days).
  • Self-harm: It is more common that people with BPD self-harm, and they may see it as a way to help emotional regulation.
  • Unstable relationships: People with BPD have intense and conflict-riddled relationships, whereas those with bipolar disorder can have difficulty maintaining relationships.
  • Mania: Impulsivity is a feature of both BPD and bipolar disorder, but with bipolar disorder it is usually only associated with periods of mania, which is not the case with BPD.

Do they require the same treatment?

One of the chief differences between the two conditions is the way in which they are treated.

Despite psychotherapy also being useful, bipolar disorder is mostly treated using medication. Mood stabilizers such as lithium are commonly used to prevent extreme mood changes between highs and lows. Other kinds of medication prescribed include antipsychotics (such as aripiprazole) and anti-convulsants (such as carbamazepine).

BPD on the other hand is primarily treated using psychotherapy. Therapies used to treat BPD include dialectical behavior therapy (DBT), cognitive behavioral therapy (CBT) and group therapy. Medication that can be prescribed to treat BPD includes mood stabilizers, antidepressants, and anti-anxiety medications.

  1. Kulacaoglu, F., & Kose, S. (2018). Borderline Personality Disorder (BPD): In the Midst of Vulnerability, Chaos, and Awe. Brain Sciences, 8(11), 201. doi: 10.3390/brainsci8110201.
  2. Brüne, M., (2016). Borderline Personality Disorder: Why ‘fast and furious’?, Evolution, Medicine, and Public Health, 2016(1), 52-66.
  3. McCormick U., Murray B., & McNew B. (2015). Diagnosis and treatment of patients with bipolar disorder: A review for advanced practice nurses. Journal of the American Association of Nurse Practitioners, 27(9), 530-542. doi: 10.1002/2327-6924.12275.
  4. Rowland, T.A., & Marwaha, S. (2018). Epidemiology and risk factors for bipolar disorder. Therapeutic Advances in Psychopharmacology, 8(9),251-269. doi:10.1177/2045125318769235
  5. Sanches, M. (2019). The Limits between Bipolar Disorder and Borderline Personality Disorder: A Review of the Evidence. Diseases, 7(3), 49. doi: 10.3390/diseases
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Arthur Mead
Author Arthur Mead Writer

Arthur Mead is a medical writer with a non-profit sector background, committed to raising awareness about mental health.

Published: Feb 20th 2023, Last edited: Sep 22nd 2023

Dr. Jenni Jacobsen, PhD
Medical Reviewer Dr. Jenni Jacobsen, PhD LSW, MSW

Dr. Jenni Jacobsen, PhD is a medical reviewer, licensed social worker, and behavioral health consultant, holding a PhD in clinical psychology.

Content reviewed by a medical professional. Last reviewed: Feb 20th 2023