Written by: THE BALANCE
Medically reviewed by Dr. Sarah Boss, MD
Last updated: January 19, 2026
Fact checked
Quick Summary
  • Borderline personality disorder, or BPD, has been a controversial diagnosis since it was formally recognized in 1980 by the Diagnostic and Statistical Manual of Mental Disorders.
  • One of the controversies it faces that still awaits a decision is whether or not it is related to bipolar disorder.
  • However, these shifts can be so extreme for some that they indicate a psychiatric disorder, like BPD or bipolar disorder.
Reading time: 10 min

Borderline personality disorder, or BPD, has been a controversial diagnosis since it was formally recognized in 1980 by the Diagnostic and Statistical Manual of Mental Disorders. One of the controversies it faces that still awaits a decision is whether or not it is related to bipolar disorder.

Changing moods is often a part of the natural response to stressful situations. However, these shifts can be so extreme for some that they indicate a psychiatric disorder, like BPD or bipolar disorder. Both conditions usually have partial similarity in mood shifts which often confuses many people, even some clinicians. Some may even believe that both disorders are similar, if not the same, or somehow connected.

Is borderline personality disorder the same as bipolar disorder? How can you differentiate between the two? This article will compare the two diseases regarding symptoms, causes, diagnosis, and treatment.

Following are some prominent symptoms of BPD: (source: APA, n.d.)

  • Dramatic emotional changes that may last from a few hours to a few days
  • Inappropriate anger
  • Impulsive or unsafe behaviors
  • Feelings of emptiness
  • Thoughts of self-harm
  • Poor self-worth 
  • Distortion of self-image
  • Chronic depression
  • Unstable relationships
  • Fear of abandonment

People with BPD may also engage in uncontrolled aggression more frequently. Their natural impulsiveness may make them more likely to engage in addiction and gambling. The symptoms are usually brought on by a conflict with someone else or a traumatic event.

On the other hand, the symptoms of bipolar disorder include dramatic changes in mood states. It usually has two different states of mood i.e.

  • Periods of irritable, expansive, or elevated mood, called manic episodes
  • Periods of sadness, hopelessness, and emptiness, called depressive episodes

Experiencing both mania and depression in bipolar sets it apart from BPD, in which a person only suffers from depressive episodes. Following are the symptoms of mania in bipolar disorder: (source: NIMH, n.d.)

  • Inflated self-esteem or grandiosity
  • Decreased need for sleep
  • Elevated mood
  • Irritability
  • Euphoric feelings
  • Excessively talkative
  • Clouded judgment
  • Racing thoughts
  • Easy distraction
  • Threatening behavior

Depressive episodes, on the other hand, are characterised by:

  • Low mood
  • Feelings of guilt
  • Limited expression
  • cognitive and memory impairment
  • Lack of will and energy
  • Soft, slow speech
  • Weight changes
  • Recurring thoughts of death
  • Overemphasis on negative feelings
  • Insomnia

Between the cycles, bipolar people often experience symptom-free periods that may last for weeks, months, or even years. This is in contrast to people with BPD, who usually have more persistent emotional symptoms existing on a day-to-day basis.

Multiple complex factors can lead to bipolar or BPD in individuals. (source: NIMH, n.d. (BD))

Most incidences of emotional dysregulation related to BPD occur due to relationship interactions. On the other hand, bipolar symptoms are primarily caused by anything that causes chemical imbalances in the brain, such as a stressful life event.

Borderline Personality Disorder Causes

The exact of BPD is still under research, and scientists are not entirely sure what triggers this disorder. However, the evidence so far suggests that different environmental factors, especially the ones in early childhood, significantly impact its development. As a result, BPD is particularly prevalent in people with a history of sexual, physical, or emotional abuse or parental neglect. Substance use by parents or a primary caregiver also seems to be another contributing factor. Research also shows that experiencing trauma and stress as a child and failing to cope with them can lead to acquiring BPD symptoms in later stages of life.

Radiological studies have shown that individuals with BPD have various brain functional and structural changes. These changes are particularly prevalent in areas that control emotional regulation, like the amygdala or orbitofrontal cortex.

Bipolar Disorder Causes

Just like BPD, the causes of bipolar disorder are also complex. Many agree that no single reason directly contributes to its development. Instead, a combination of various factors paves the path for the symptoms of BPD to set in. Some research also suggests that the presence of specific genes predisposes an individual to this disorder. Researchers also believe that bipolar stems from chemical imbalances in the brain. (source: NHS, n.d. (BPD))

A mental health professional begins to diagnose BPD or bipolar disorder by asking an individual some questions about their symptoms, severity, and duration. They may also inquire about the individual’s personal and family medical history, focusing on whether or not someone in their relatives has a mental illness. Some experts prefer using questionnaires to gather data about the symptoms and use it to establish a diagnosis.

For example, to diagnose bipolar type one, a person must have had at least one episode of mania lasting for at least seven days or severe enough to warrant hospitalisation. Similarly, they may be labelled as a case of bipolar type two if they suffer from a major depressive episode followed by an episode of hypomania.

In cases where a doctor finds it challenging to differentiate bipolar disorder from BPD, they may focus on specific symptoms to distinguish them from each other. These symptoms include: (source: NHS, n.d. (BD))

Sleep

People with bipolar disorder tend to suffer from highly disturbed sleep cycles during an active episode of mania or depression. Conversely, those with BPD do not generally have any sleep disturbances.

Duration of Cycling Mood

Besides those suffering from rapid cycling bipolar disorder, most bipolar people experience mood cycles that last weeks to months. On the other hand, those with BPD experience sudden mood shifts that are usually short-lived and may subside within hours or days.

Self-harm

Surveys suggest that up to 75 per cent of people diagnosed with BPD indulge in self-harming practices. They may perceive self-harm as a way to regulate their emotions or control their intense or uncontrolled feelings. People with bipolar disorder do not commonly practice self-harm; however, they tend to have a much higher suicide rate at the same time. (source: NICE, 2023 (BPD))

Unstable Relationships

Individuals with BPD usually have conflict-riddled and highly complex relationships. Bipolar individuals may also experience difficulty maintaining relationships due to the nature and severity of their symptoms.

Mania

Individuals with bipolar disorder may commonly adopt impulsive behaviors during an active episode of mania. Similar impulsiveness might be observed in people with BPD, but the behavior is not related to mania.

Mentioned below is some additional information to distinguish BPD from bipolar disorder:

Family History

Mood disorders, including bipolar disorder, usually run in families even though the specific gene responsible for this genetic predisposition is yet to be discovered. BPD also has a genetic predisposition, but the link is not as strong. (source: NICE, 2022 (BD))

Past Trauma

While the cause of BPD remains unclear, many people with this disorder have experienced trauma in their childhood. Some examples of trauma leading to BPD include abuse, extreme adversity, unstable family, abandonment, exposure to conflict, etc.

The most crucial common highlight of treatment for BPD and bipolar disorder is the need for a personalized plan tailored to each client for a wholesome recovery.

Treatment for BPD

In the case of BPD, psychotherapy is usually the first-line treatment. There are multiple types of empirically-supported therapies that can successfully manage BPD symptoms. These include: (source: StatPearls, 2025 (BPD))

  • Dialectical behavioral therapy (DBT) provides help with emotional management.
  • Mentalization-based therapy (MBT) helps clients better understand what happens in their minds during an active episode of symptoms.

The use of medications for BPD symptom management is rare since their benefits are less clear to the experts at the moment. Sometimes, a psychiatrist may prescribe some drugs to control specific symptoms, like depression, mood swings, and other co-occurring mental issues.

Apart from therapeutic management, people with BPD are also encouraged to adopt certain lifestyle adjustments that introduce more balance in their mood. Additionally, they can benefit from certain self-care habits, like getting adequate sleep, exercising every day, and actively participating in psychoeducation.

Treatment for Bipolar Disorder 

A diagnosis of bipolar disorder is associated with an increased risk of mortality and reduction in life expectancy unless treatment is sought. The treatment protocol for this psychiatric illness includes a combination of psychotherapy and medications. A psychiatrist typically prescribes second-generation antipsychotic medication and mood stabilisers to control mood swings. Some people may also benefit from using antidepressant medication during depressive bipolar episodes. (source: StatPearls, 2025 (BD))

In addition to medication, psychotherapies, such as cognitive behavioral therapy and psychoeducation, can also benefit bipolar individuals. Additionally, an expert may suggest joining family-focused, social rhythm and interpersonal therapy to improve the chances of recovery.

Another treatment modality used in resistant cases of bipolar disorder is electroconvulsive therapy or ECT. ECT refers to a brain stimulation process used for managing severe and refractory episodes of depression or mania. Alternatively, some experts may use transcranial magnetic stimulation to treat the depressive phases.

Remember that despite the differences, bipolar and BPD are lifelong conditions, and ongoing treatment is essential to manage them.

FAQs

What are the triggers of borderline personality disorder?
The mood swings related to BPD can be triggered by multiple factors, such as a fear of abandonment, criticism, fights with loved ones, romantic issues, rejection, job loss, traumatic memories, etc.
What do you mean by splitting into borderline personality disorder?
Splitting BPD, also known as black-and-white thinking, refers to an inability to hold opposing feelings, beliefs, or thoughts. People suffering from this type of BPD often have an all-or-nothing attitude which means they always consider something or someone as either always good or bad. This unusual way of viewing others is a typical defense mechanism that may result in acting out, denial, projection, or a feeling of omnipotence.
Can you have BPD and bipolar disorder at the same time?
Yes, some people can have both issues together; however, experts continue to research their connection with each other. At the moment, there are varying opinions regarding the possibility of interdependence or an association between the two. For example, one study has found that up to 20 per cent of people with a BPD diagnosis also have bipolar disorder simultaneously. Another study that investigated people with both BPD and bipolar disorder for ten years found that the disorders occur entirely independent of each other. Regardless of where the ongoing research leads us, the experts strongly agree that each disorder must be treated individually for the best outcomes.
Which is worse, bipolar or BPD?
There is no definitive answer to this question as different people may have different individual experiences with both diseases. However, from a theoretical point of view, BPD seems to have more intense emotional symptoms as compared to the cycling emotions in bipolar disorder. On the other hand, because BPD symptoms are usually short-lived and tend to last up to a few hours at a time, some people find it more manageable than bipolar symptoms, which may last for weeks. 
What is rapid cycling bipolar disorder?
Rapid cycling bipolar disorder refers to an unusually faster and frequent transition from mania or hypomania BPD to depression and vice versa. For a person to be diagnosed with this subtype of bipolar disorder, they must experience at least four or more any kind of BPD episodes within 12 months. Some of these episodes may last for days, while others can continue for weeks or even more.

The Article

+

References

+

About This Article

+

Do you need help?

Sister Topics

Borderline Personality Disorder Treatment Borderline Personality Disorder: Signs & Dangers BPD And Alcohol BPD And Paranoia BPD Parent BPD Splitting DBT For BPD Emotional Dysregulation Disorder Inpatient Treatment For Borderline Personality Disorder Petulant BPD What is Borderline What Is Splitting BPD