Bipolar Disorder vs. Borderline Personality Disorder: How To Tell the Difference

The two mental health conditions are sometimes confused—but treatment depends on which diagnosis a person actually has.

When it comes to successfully treating a mental health disorder, it is important to have the correct diagnosis. Unfortunately, symptoms of different conditions can overlap, making it tough to find the right diagnosis.

Bipolar disorder and borderline personality disorder (BPD) may sound similar at first and they do share a few similarities, but the two conditions are very different.

What Is Bipolar Disorder?

Bipolar disorder is a mental illness that causes high and low moods, also known as mania and depression. These moods are more extreme than the mood changes most people experience; they can affect how well people with bipolar disorder can live their life.

Periods of mania or depression vary in length but often last days or weeks. Other symptoms of bipolar disorder include:

  • Changes in sleep patterns and activity levels
  • Uncharacteristic behaviors
  • Periods of unusually intense emotion

Manic State

To be diagnosed with bipolar disorder, a person must have at least one manic or hypomanic episode. Hypomania is a less severe form of mania—it does not include psychotic episodes. However, both types of mania are associated with higher energy and impulsive behavior. Suicide is "an ever-present danger" in people with bipolar disorder because they may become suicidal during a manic state.

Depressed State

On the other extreme of the mood scale, people with bipolar disorder can swing from a manic state to a depressed state. During a depression, some people have trouble sleeping while others sleep more than usual. They may feel overwhelmed by making decisions and become obsessed with negative thoughts.

What Is BPD?

Borderline personality disorder is also a mental illness that affects mood. BPD can cause people to have difficulty regulating their emotions—they feel these emotions more strongly and these emotions can change suddenly. This can cause:

  • Feelings of abandonment
  • Efforts to avoid abandonment
  • Unstable personal relationship
  • Distorted self-image
  • Self-harming behaviors
  • Chronic feelings of boredom or emptiness
  • No sense of self

Having unstable relationships is a defining factor of BPD. People with BPD often do something called "splitting" where they suddenly alternate between idealizing their partner and disliking their partner without reason.

Symptoms of Bipolar Disorder and BPD

Overall, bipolar disorder and BPD are two different conditions with different symptoms. But there are some similarities, as well as clear differences.

Length of Mood Changes

Though both conditions involve mood swings, the length of mood changes can vary. Those with bipolar disorder can experience episodes of mania or depression that can last several days to weeks. Their mood changes are usually in response to interactions within their relationships. They can also have periods of time without symptoms that can last anywhere from days to years.

This is different from people who have BPD because they experience symptoms almost everyday. These mood changes are shorter, more persistent, and tend to occur as a result of stress (or other environmental factors).


The emotions felt during mood swings can also differ. People with bipolar disorder fluctuate from manic or depressive states (or both at once) while people with BPD don't generally have manic episodes but they can experience feelings of intense depression.

Both people with BPD and people with bipolar disorder can have intense emotions, suicidal thinking, and impulsive behaviors.

Bipolar Disorder and BPD Treatment Options

The treatment options for bipolar disorder and BPD are similar. But even though treatment options are similar, treating bipolar disorder is easier than treating BPD.

Treatment for Bipolar Disorder

Once properly diagnosed, bipolar disorder can be extremely well-managed with the following treatment options:

  • Cognitive behavioral therapy can provide you and your loved ones with support as well as skills and strategies to cope with your diagnosis and your symptoms.
  • Medication may involve mood stabilizers, antipsychotics, and/or antidepressants.
  • Meditation and exercise can help you manage symptoms of depression, anxiety, and difficulty sleeping.
  • Electroconvulsive therapy (ECT) and transcranial magnetic stimulation (TMS) are procedures that that involve brain stimulation and may relieve symptoms.

Like many health conditions, having a support team is also important. People with bipolar disorder who successfully manage their condition often count on their loved ones and healthcare providers. Treatment can vary with each person so discuss your treatment options with a healthcare provider.

Treatment for BPD

Treating BPD can help improve quality of life, symptoms, and functioning, but it may be difficult. Treatment should be received from a licensed mental health professional, or it may not be effective.

Similar to bipolar disorder, cognitive behavioral therapy is important in the treatment of BPD. Additionally, dialectical behavioral therapy (DBT) focuses on awareness of your emotions and was created specifically for people with BPD.

As for medication, there is no one medication designed to treat the core symptoms of borderline personality disorder. But medications for certain symptoms, like depression and mood swings, may help.

A Quick Review

Bipolar disorder and borderline personality disorder are both mental illnesses that affect the emotions and moods of those who are diagnosed with it. Although they may appear similar, there are certain differences—like the length and type of symptoms—that make them two completely different disorders.

If you or a loved one are looking for support or treatment options for bipolar disorder or BPD, reach out to a healthcare provider who can determine the best course of treatment for you or your loved one.

Looking for support?

If you are in crisis, or know someone who is, call or text the National Suicide Prevention Lifeline by using the three-digit dialing code 988.

You can also go to for a list of additional resources.

Was this page helpful?
6 Sources 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.
  1. National Institute of Mental Health. Bipolar disorder.

  2. National Alliance on Mental Illness. Bipolar disorder.

  3. National Alliance on Mental Illness. Borderline personality disorder.

  4. National Alliance on Mental Illness. Borderline personality disorder and bipolar disorder: what's the difference?

  5. National Library of Medicine. Bipolar disorder.

  6. National Institute of Mental Health. Borderline personality disorder.

Related Articles