Bipolar disorder and borderline personality disorder (BPD) are two mental health conditions. They affect millions of people each year. These conditions have some similar symptoms, but there are distinctions between them.

Symptoms common to both bipolar disorder and BPD include:

  • changes in mood
  • impulsivity
  • low self-esteem or self-worth, particularly during lows for people with bipolar disorder

While bipolar disorder and BPD do share similar symptoms, the majority of symptoms don’t overlap.

Symptoms of bipolar disorder

It’s estimated that up to 2.6 percent of American adults have bipolar disorder. This condition used to be called manic depression. The condition is characterized by:

  • extreme changes in mood
  • euphoric episodes called mania or hypomania
  • episodes of deep lows or depression

During a manic period, a person with bipolar disorder may be more active. They may also:

  • experience greater physical and mental energy than usual
  • require less sleep
  • experience fast-paced thought patterns and speech
  • engage in risky or impulsive behaviors, such as substance use, gambling, or sex
  • make grand, unrealistic plans

During periods of depression, a person with bipolar disorder may experience:

  • drops in energy
  • inability to concentrate
  • insomnia
  • loss of appetite

They may feel a deep sense of:

  • sadness
  • hopelessness
  • irritability
  • anxiety

In addition, they may have suicidal thoughts. Some people with bipolar disorder may also experience hallucinations or breaks in reality (psychosis).

In a manic period, a person may believe they have supernatural powers. In a period of depression, they may believe they have done something wrong, such as causing an accident when they have not.

Symptoms of BPD

An estimated 1.6 to 5.9 percent of American adults live with BPD. People with the condition have chronic patterns of unstable thoughts. This instability makes it difficult to regulate emotions and impulse control.

People with BPD also tend to have a history of unstable relationships. They may try hard to avoid feeling abandoned, even if it means staying in unhealthy situations.

Stressful relationships or events may trigger:

  • intense changes in mood
  • depression
  • paranoia
  • anger

People with the condition may perceive people and situations in extremes — all good, or all bad. They’re also likely to be very critical of themselves. In severe cases, some people may engage in self-harm, like cutting. Or they may have suicidal thoughts.

Researchers aren’t sure what causes bipolar disorder. But it’s thought that a few things contribute to the condition, including:

A broad combination of biological and environmental factors may cause BPD. These include:

More research is needed to understand the causes for both of these conditions.

The risks of developing bipolar disorder or BPD have been linked to the following:

  • genetics
  • exposure to trauma
  • medical issues or functions

However, there are other risk factors for these conditions that are quite different.

Bipolar disorder

The relationship between bipolar disorder and genetics remains unclear. People who have a parent or sibling with bipolar disorder are more likely to have the condition than the general public. But, in most cases people with a close relative who has the condition will not develop it.

Additional risk factors for bipolar disorder include:

Borderline personality disorder

BPD is five times more likely to be present in people who have a close family member, such as a sibling or parent, with the condition.

Additional risk factors for BPD include:

  • early exposure to trauma, sexual assault, or PTSD (However, most people who experience trauma will not develop BPD.)
  • genetic abnormalities that affect brain functions

A medical professional must diagnose bipolar disorder and BPD. Both conditions require psychological and medical exams to rule out other issues.

Bipolar disorder

A doctor may recommend the use of mood journals or questionnaires to help diagnose bipolar disorder. These tools can help show patterns and frequency of changes in mood.

Bipolar disorder typically falls into one of several categories:

  • Bipolar I: People with bipolar I have had at least one manic episode immediately before or after a period of hypomania or a major depressive episode. Some people with bipolar I have also experienced psychotic symptoms during a manic episode.
  • Bipolar II: People with bipolar II have never experienced a manic episode. They have experienced one or more episodes of major depression, and one or more episodes of hypomania.
  • Cyclothymic disorder: Criteria for cyclothymic disorder includes a period of two or more years, or one year for children under 18, of fluctuating episodes of hypomanic and depressive symptoms.
  • Other: For some people, bipolar disorder is related to a medical condition such as stroke or thyroid dysfunction. Or it’s triggered by substance abuse.

Borderline personality disorder

In addition to psychological and medical exams, the doctor may use a questionnaire to learn more about symptoms and perceptions, or interview the patient’s family members or close friends. The doctor may try to rule out other conditions before making an official diagnosis of BDP.

Can I be misdiagnosed?

It is possible that bipolar disorder and BPD may be confused with each other. With either diagnosis, it’s important to follow up with medical professionals to ensure a proper diagnosis has been made, and to ask questions about treatment if symptoms arise.

There’s no cure for bipolar disorder or BPD. Instead, treatment will focus on helping manage symptoms.

Bipolar disorder is commonly treated with medication, such as antidepressants and mood stabilizers. Medication is typically paired with psychotherapy.

In some cases, a doctor may also recommend treatment programs for additional support while people with this condition adjust to medication and gain control over their symptoms. Temporary hospitalization may be recommended for people with severe symptoms, such as suicidal thoughts or self-harming behaviors.

Treatment for BPD typically focuses on psychotherapy. Psychotherapy can help someone view themselves and their relationships more realistically. Dialectical behavior therapy (DBT) is a treatment program that combines individual therapy with group therapy. It’s been shown to be an effective treatment for BPD. Additional treatment options include other forms of group therapy, and visualization or meditation exercises.

Online therapy options

Read our review of the best online therapy options to find the right fit for you.

Bipolar disorder and BPD have some overlapping symptoms, but these conditions are different from one another. Treatment plans may vary depending on the diagnosis. With a proper diagnose, medical care, and support, it’s possible to manage bipolar disorder and BPD.