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Borderline Personality Disorder

What is borderline personality disorder?

Borderline personality disorder is a mental illness that severely impacts a person’s ability to manage their emotions. This loss of emotional control can increase impulsivity, affect how a person feels about themselves, and negatively impact their relationships with others. Effective treatments are available that can help people manage the symptoms of borderline personality disorder.

What are the signs and symptoms of borderline personality disorder?

People with borderline personality disorder may experience intense mood swings and feel uncertainty about how they see themselves. Their feelings for others can change quickly, and swing from extreme closeness to extreme dislike. These changing feelings can lead to unstable relationships and emotional pain.

People with borderline personality disorder also tend to view things in extremes, such as all good or all bad. Their interests and values can change quickly, and they may act impulsively or recklessly.

Other signs or symptoms may include:

  • Efforts to avoid real or perceived abandonment, such as plunging headfirst into relationships—or ending them just as quickly.
  • A pattern of intense and unstable relationships with family, friends, and loved ones.
  • A distorted and unstable self-image or sense of self.
  • Impulsive and often dangerous behaviors, such as spending sprees, unsafe sex, substance misuse, reckless driving, and binge eating. However, if these behaviors happen mostly during times of elevated mood or energy, they may be symptoms of a mood disorder and not borderline personality disorder.
  • Self-harming behavior, such as cutting.
  • Recurring thoughts of suicidal behaviors or threats.
  • Intense and highly variable moods, with episodes lasting from a few hours to a few days.
  • Chronic feelings of emptiness.
  • Inappropriate, intense anger or problems controlling anger.
  • Feelings of dissociation, such as feeling cut off from oneself, observing oneself from outside one’s body, or feelings of unreality.

Not everyone with borderline personality disorder will experience all of these symptoms. The severity, frequency, and duration of symptoms depend on the person and their illness.

People with borderline personality disorder have a significantly higher rate of self-harming and suicidal behavior than the general population.

If you or someone you know is struggling or having thoughts of suicide, call or text the 988 Suicide and Crisis Lifeline  at 988 or chat at . In life-threatening situations, call 911.

What are the risk factors for borderline personality disorder?

Studies suggest that genetic, environmental, and social factors may increase the likelihood of developing borderline personality disorder. These factors may include:

  • Family history: People who have a close family member (such as a parent or sibling) with the illness may be more likely to develop borderline personality disorder due to shared genetic factors.
  • Brain structure and function: Research shows that people with borderline personality disorder may have structural and functional changes in the brain, especially in areas that control impulses and emotion regulation. However, it is not clear whether these changes led to the disorder or were caused by the disorder.
  • Environmental, cultural, and social factors: Many people with borderline personality disorder report having experienced traumatic life events, such as abuse, abandonment, or hardship, during childhood. Others may have experienced unstable, invalidating relationships or conflicts.

How is borderline personality disorder diagnosed?

A licensed mental health professional—such as a psychiatrist, psychologist, or clinical social worker—can diagnose borderline personality disorder based on a thorough evaluation of a person’s symptoms, experiences, and family medical history. A careful and thorough medical exam can help rule out other possible causes of symptoms.

Borderline personality disorder is usually diagnosed in late adolescence or early adulthood. Occasionally, people younger than age 18 may be diagnosed with borderline personality disorder if their symptoms are significant and last at least 1 year.

What other illnesses can co-occur with borderline personality disorder?

Borderline personality disorder often occurs with other mental illnesses, such as post-traumatic stress disorder (PTSD). These co-occurring disorders can make it harder to correctly diagnose and treat borderline personality disorder, especially when the disorders have overlapping symptoms. For example, a person with borderline personality disorder also may be more likely to experience symptoms of major depression, PTSD, bipolar disorder, anxiety disorders, substance use disorder, or eating disorders.

How is borderline personality disorder treated?

With evidence-based treatment, many people with borderline personality disorder experience fewer and less severe symptoms, improved functioning, and better quality of life. It is important for people with borderline personality disorder to receive treatment from a licensed mental health professional.

It can take time for symptoms to improve after treatment begins. It is important for people with borderline personality disorder and their loved ones to be patient, stick with the treatment plan, and seek support during treatment.

Some people with borderline personality disorder may need intensive, often inpatient, care to manage severe symptoms, while others may be able to manage their symptoms with outpatient care.


Psychotherapy (sometimes called talk therapy) is the main treatment for people with borderline personality disorder. Most psychotherapy occurs with a licensed, trained mental health professional in one-on-one sessions or with other people in group settings. Group sessions can help people with borderline personality disorder learn how to interact with others and express themselves effectively.

  • Dialectical behavior therapy (DBT) was developed specifically for people with borderline personality disorder. DBT uses concepts of mindfulness or awareness of one’s present situation and emotional state. DBT also teaches skills to help people manage intense emotions, reduce self-destructive behaviors, and improve relationships.
  • Cognitive behavioral therapy (CBT) can help people with borderline personality disorder identify and change core beliefs and behaviors that come from inaccurate perceptions and problems interacting with others. CBT may help people reduce mood swings and anxiety symptoms and may reduce the number of self-harming or suicidal behaviors.


The benefits of mental health medications for borderline personality disorder are unclear and medications aren’t typically used as the main treatment for the illness. In some cases, a psychiatrist may recommend medications to treat specific symptoms or co-occurring mental disorders such as mood swings or depression. Treatment with medications may require coordinated care among several health care providers.

Medications can sometimes cause side effects in some people. Talk to your health care provider about what to expect from a particular medication. To find the latest information about medications, talk to a health care provider and visit the Food and Drug Administration website .

Therapy for caregivers and family members

More research is needed to determine how well family therapy helps with borderline personality disorder. Studies on other mental disorders show that including family members can help support a person’s treatment. Families and caregivers also can benefit from therapy.

Family therapy helps by:

  • Allowing people to develop skills to understand and support a loved one with borderline personality disorder
  • Focusing on the needs of family members to help them understand the obstacles and strategies for caring for their loved one

How can I find help for borderline personality disorder?

If you’re not sure where to get help, a health care provider can refer you to a licensed mental health professional, such as a psychiatrist or psychologist with experience treating borderline personality disorder. Find tips to help prepare for and get the most out of your visit and information about getting help.

The Substance Abuse and Mental Health Services Administration has an online treatment locator  to help you find mental health services in your area.

Here are some ways to help a friend or family member with borderline personality disorder:

  • Take time to learn about the illness to understand what your friend or relative is experiencing.
  • Offer emotional support, understanding, patience, and encouragement. Change can be difficult and frightening to people with borderline personality disorder, but things can improve over time.
  • Encourage your loved one in treatment for borderline personality disorder to ask about family therapy.
  • Seek counseling for yourself. Choose a different therapist than the one your relative is seeing.

How can I find a clinical trial for borderline personality disorder?

Clinical trials are research studies that look at new ways to prevent, detect, or treat diseases and conditions. The goal of clinical trials is to determine if a new test or treatment works and is safe. Although individuals may benefit from being part of a clinical trial, participants should be aware that the primary purpose of a clinical trial is to gain new scientific knowledge so that others may be better helped in the future.

Researchers at NIMH and around the country conduct many studies with patients and healthy volunteers. We have new and better treatment options today because of what clinical trials uncovered years ago. Talk to your health care provider about clinical trials, their benefits and risks, and whether one is right for you.

To learn more or find a study, visit:

Where can I learn more about borderline personality disorder?

Free brochures and shareable resources

Federal resources

Research and statistics

  • Journal Articles : This webpage provides articles and abstracts on borderline personality disorder from MEDLINE/PubMed (National Library of Medicine).
  • Statistics: Personality DisordersThis webpage provides the statistics currently available on the prevalence of personality disorder among people in the United States.


Last Reviewed: April 2024

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