BPD vs. Bipolar

How Moods, Episodes, and Treatment Compare

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Borderline personality disorder (BPD) and bipolar disorder (BD) are mental illnesses associated with dramatic mood swings. Bipolar is a mood disorder and BPD is a personality disorder.

Given some shared symptoms, they are often confused with one another. The differences in BPD vs. bipolar can, however, help steer a diagnosis. The two also have different causes and treatments.

Borderline Personality Disorder vs. Bipolar Disorder

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This article discusses the differences and similarities between BPD and bipolar disorder. It also details the different causes and treatments of the two mental health conditions.

Symptoms of BPD vs. Bipolar

BPD and bipolar share some of the same traits, but they have different symptom patterns, durations, and triggers.

Some symptoms are also more common with one versus the other. For example, both BPD and bipolar are characterized by emotional turbulence and impulsive behavior. People with BPD often have unstable personal relationships, which is not as common in bipolar disorder.

  • Dramatic emotional changes, lasting from a few hours to a few days

  • Engages in impulsive or unsafe behaviors

  • Often has inappropriate anger or uncontrolled aggression

  • Feelings of emptiness and low self-worth 

  • Self-injury or thoughts of self-harm are more common

  • Chronic depression

  • Distorted self-image

  • Fear of abandonment

  • Commonly involved in intense and unstable relationships, but may lack close or trusted friends

  • Shorter cycles of mood instability

  • Episodes often linked to stress

  • Dramatic mood changes, extreme highs and lows that last weeks to months

  • Elevated moods and self-esteem during manic episodes

  • Flat or depressed mood during down episodes

  • Fluctuations in weight, energy levels, and sleep needs

  • Racing thoughts, impaired judgement, impulsivity, and excessive talking

  • Slow speech, impaired cognition, and memory issues

  • Threatening or combative

  • Possibly suicidal when depressed

  • Frequently has a genetic component

BPD Symptoms

The main symptoms of BPD include:

  • Dramatic emotional changes, lasting from a few hours to a few days
  • Impulsive, risky, and unsafe behavior
  • Inappropriate anger
  • Feelings of emptiness and low self-worth 
  • Self-injury or thoughts of self-harm
  • Chronic depression
  • Distorted self-image
  • Fear of abandonment
  • Unstable and intense relationships

People with BPD may also show signs of uncontrolled aggression. The impulsive nature of BPD can make a person more likely to engage in addictive behavior, like drug use and gambling. Moreover, the symptoms are usually triggered by a conflict with another person or institution. A traumatic or stressful event can also cause an increase in BPD symptoms.

Another feature of BPD is called splitting. This term, which refers to two things being split in half, is when someone is unable to hold emotionally opposing viewpoints in relation to themselves and others. It is usually a coping or defense mechanism to manage the intense fear of abandonment, and it can result in impulsive behaviors and relationship difficulties.

Bipolar Disorder Symptoms

The main symptoms of bipolar include dramatic changes in mood states. The highs, or elevated, expansive, or irritable periods, are considered manic episodes. The lows, or sad, empty, or hopeless periods, are depressive episodes. Experiencing both manic episodes and depressive episodes differentiates BD from major depressive disorder (MDD), which is dominated by only depressive episodes.

During manic episodes, symptoms of bipolar include:

  • Decreased need for sleep
  • Inflated self-esteem or grandiosity
  • Elevated mood, euphoria, and irritability
  • Excessively talkative
  • Racing thoughts
  • Impaired judgment
  • Easy distraction
  • Threatening and assaultive behavior

During depressive episodes, symptoms of bipolar include: 

  • Depressed mood
  • Flat or limited expression
  • Feelings of guilt and failure
  • Impairment in cognition and memory
  • Soft, slow speech
  • Lack of energy and motivation
  • Overemphasis on negative feelings and beliefs
  • Weight changes
  • Insomnia
  • Recurrent thoughts of death or suicide

It’s also important to understand manic episodes in bipolar aren’t necessarily beneficial, even though they’re the alternative to depressive episodes. People experiencing mania can be reckless. They often lack self-awareness and are unable to understand how their impulses affect themselves and others.

People with bipolar I disorder often have cycles that switch from a depressive state to a manic state. Manic symptoms sometimes include symptoms of depression within the manic episode, which is called mixed features.

Between cycles, people with bipolar disorder often have periods of true symptom-free wellness lasting weeks, months, or years.

On the other hand, people diagnosed with BPD typically have more persistent day-to-day emotional symptoms that can impact everyday life.


There are a number of complex factors that can cause BPD or bipolar.

Many of the experiences with emotional dysregulation in BPD are in response to relationship interactions, while bipolar symptoms can be triggered by a wide variety of factors, including chemical imbalances in the brain and stressful life events.

Borderline Personality Disorder Causes

The exact cause of BPD is not entirely known, but research suggests that it can be influenced by environmental factors, especially those in early childhood.

A history of emotional, physical, or sexual abuse or parental neglect is prevalent in people with BPD. Parental substance abuse is another potential cause. Research has shown that experiencing stress and trauma as a child and an inability to cope can contribute to BPD later in life.

Genetics, chemical imbalances, and brain structure may also play a role in BPD. People with a family history of BPD are at higher risk of having the condition. Many people with BPD have altered brain neurotransmitter function, particularly serotonin.

Studies have shown that people with BPD can have structural and functional changes in the brain, especially in the areas that control impulses and emotional regulation like the amygdala, hippocampus, and orbitofrontal cortex.

Bipolar Disorder Causes

The causes of bipolar disorder are complex. Most agree that there is no one single cause, and a combination of factors often contributes to BD. People who have a direct relative with BD are more likely to develop it. Some research also suggests that people with certain genes are more likely to develop bipolar. 

Researchers believe that chemical imbalances play a role in bipolar. There is evidence that an imbalance in one or more neurotransmitters may result in bipolar symptoms.


According to the Diagnostic and Statistical Manual 5th Edition (DSM-5), which psychologists, psychiatrists, and other mental health professionals use for diagnosing mental health conditions, bipolar is diagnosed when a person experiences a manic episode that may have been preceded or followed by a depressive episode.

Bipolar 2 disorder is diagnosed when hypomania (less severe mania) and depressive episodes have been present.

Some subtle diagnostic distinctions between BPD and bipolar disorder:

  • Duration: A manic or depressive episode of bipolar can last weeks, months, or longer. In contrast, people with BPD have shorter episodes of mood instability that are reactive to stress.
  • Family history: Genetic factors can also help differentiate the two. Mood disorders, like bipolar, are more likely to be passed down through family members than borderline personality disorder.
  • Sleep: Sleep changes are often an early indicator of bipolar disorder. In bipolar disorder during a manic episode, a person might be awake for days without experiencing fatigue. Meanwhile, sleep patterns are less commonly affected in BPD.
  • Relationships: People with BPD have more distinct challenges interacting with others, so they often have a history of turbulent personal relationships or may lack close and trusted friends.
  • Self-harm: Self-harm behaviors such as cutting are more common in BPD.

It isn’t uncommon for BPD and bipolar to occur simultaneously. Current research shows that 10% of people diagnosed with bipolar I disorder are also diagnosed with BPD and 20% of people diagnosed with bipolar II disorder are also diagnosed with BPD.


The most effective treatment for these conditions is a personalized treatment plan that suits the symptoms, personal needs, and lifestyle.


Psychotherapy is the first-line treatment for people with BPD.

There are several types of empirically supported psychotherapies used in BPD, including:

  • Dialectical behavioral therapy (DBT), which supports emotional management
  • Mentalization-based therapy (MBT), which promotes better understanding of what happens in your mind

The benefits of medications for BPD are less clear. In some cases, a psychiatrist may recommend medications to treat specific symptoms, such as mood swings, depression, and other co-occurring mental disorders.

Lifestyle adjustments that promote a balanced mood and practicing self-care habits, like getting regular sleep and exercise, and participating in psychoeducation, can help keep the condition under control.  

Bipolar Disorder 

Having bipolar disorder increases a person’s risk of mortality and shortens their life expectancy.

Doctors can treat BD with medications and psychotherapy. Typically, psychiatrists prescribe mood stabilizers and second-generation antipsychotics for the treatment of bipolar They may also prescribe antidepressant medication to treat depressive episodes in BD.

Psychotherapies that can be used for the treatment of bipolar disorder include cognitive-behavioral therapy and psychoeducation. Other therapies designed specifically for the treatment of BD include interpersonal and social rhythm therapy and family-focused therapy.

Sometimes bipolar is treated with electroconvulsive therapy, a brain stimulation procedure used to treat severe or refractory manic and depressive episodes, or transcranial magnetic stimulation, which stimulates the brain with magnetic waves to help treat subtypes of depression.

Since both BPD and bipolar can be lifelong conditions, ongoing treatment is essential.

A Word From Verywell

Bipolar disorder and BPD are not the same. Having bipolar or BPD can have a significant impact on your life. However, proper maintenance of symptoms can reduce the risk of potential consequences, including substance abuse, suicidal thoughts, and self-harm.

If you or a loved one may be struggling with a mental health challenge like BD or BPD, talk to your doctor about options for evaluation and treatment.

Frequently Asked Questions

  • What is the difference between bipolar disorder and ADHD?

    These conditions are often confused for one another because of some shared symptoms. The most obvious difference is that ADHD symptoms are ongoing, whereas bipolar symptoms are episodic. In addition, ADHD typically first presents in childhood. Bipolar disorder starts in late adolescence or early adulthood. 

  • What triggers a person with borderline personality disorder?

    BPD mood swings are commonly triggered by criticism, fear of abandonment, fights with friends or loved ones, job loss, rejection, romantic problems, and traumatic memories.

  • What is splitting in borderline personality disorder?

    Splitting (black-and-white thinking) is the inability to hold opposing thoughts, feelings, or beliefs. It is an all-or-nothing attitude where someone or something is either always good or always bad. It is a defense mechanism that can result in acting out, projection, denial, or a sense of omnipotence. 

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Verywell Health uses only high-quality sources, including peer-reviewed studies, to support the facts within our articles. Read our editorial process to learn more about how we fact-check and keep our content accurate, reliable, and trustworthy.
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By Michelle Polizzi
Michelle Polizzi is a freelance writer and certified yoga instructor who creates research-based health and wellness content for leading brands and publications.