People with borderline personality disorder may experience mood swings and display uncertainty about how they see themselves and their role in the world. As a result, their interests and values can change quickly.

People with borderline personality disorder also tend to view things in extremes, such as all good or all bad. Their opinions of other people can also change quickly. An individual who is seen as a friend one day may be considered an enemy or traitor the next. These shifting feelings can lead to intense and unstable relationships.

Other signs or symptoms may include:

• Efforts to avoid real or imagined abandonment, such as rapidly initiating intimate (physical or emotional) relationships or cutting off communication with someone in anticipation of being abandoned
• A pattern of intense and unstable relationships with family, friends, and loved ones, often swinging from extreme closeness and love (idealization) to extreme dislike or anger (devaluation)
• Distorted and unstable self-image or sense of self
• Impulsive and often dangerous behaviors, such as spending sprees, unsafe sex, substance abuse, reckless driving, and binge eating. Please note: If these behaviors occur primarily during a period of elevated mood or energy, they may be signs of a mood disorder—not borderline personality disorder
• Self-harming behavior, such as cutting
• Recurring thoughts of suicidal behaviors or threats
• Intense and highly changeable moods, with each episode lasting from a few hours to a few days
• Chronic feelings of emptiness
• Inappropriate, intense anger or problems controlling anger
• Difficulty trusting, which is sometimes accompanied by irrational fear of other people’s intentions
• Feelings of dissociation, such as feeling cut off from oneself, seeing oneself from outside one’s body, or feelings of unreality

Not everyone with borderline personality disorder experiences every symptom. Some individuals experience only a few symptoms, while others have many. Symptoms can be triggered by seemingly ordinary events. For example, people with borderline personality disorder may become angry and distressed over minor separations from people to whom they feel close, such as traveling on business trips. The severity and frequency of symptoms and how long they last will vary depending on the individual and their illness.

The cause of borderline personality disorder is not yet clear, but research suggests that genetics, brain structure and function, and environmental, cultural, and social factors play a role, or may increase the risk for developing borderline personality disorder.

• Family History. People who have a close family member, such as a parent or sibling with the disorder may be at higher risk of developing borderline personality disorder.
• Brain Factors. Studies show that people with borderline personality disorder can have structural and functional changes in the brain especially in the areas that control impulses and emotional regulation. But is it not clear whether these changes are risk factors for the disorder, or caused by the disorder.
• Environmental, Cultural, and Social Factors. Many people with borderline personality disorder report experiencing traumatic life events, such as abuse, abandonment, or adversity during childhood. Others may have been exposed to unstable, invalidating relationships, and hostile conflicts.

Although these factors may increase a person’s risk, it does not mean that the person will develop borderline personality disorder. Likewise, there may be people without these risk factors who will develop borderline personality disorder in their lifetime.

Borderline personality disorder has historically been viewed as difficult to treat. But, with newer, evidence-based treatment, many people with the disorder experience fewer or less severe symptoms, and an improved quality of life. It is important that people with borderline personality disorder receive evidence-based, specialized treatment from an appropriately trained provider. Other types of treatment, or treatment provided by a doctor or therapist who is not appropriately trained, may not benefit the person.

Many factors affect the length of time it takes for symptoms to improve once treatment begins, so it is important for people with borderline personality disorder and their loved ones to be patient and to receive appropriate support during treatment.

Tests and Diagnosis

A licensed mental health professional—such as a psychiatrist, psychologist, or clinical social worker—experienced in diagnosing and treating mental disorders can diagnose borderline personality disorder by:

• Completing a thorough interview, including a discussion about symptoms
• Performing a careful and thorough medical exam, which can help rule out other possible causes of symptoms
• Asking about family medical histories, including any history of mental illness

Borderline personality disorder often occurs with other mental illnesses. Co-occurring disorders can make it harder to diagnose and treat borderline personality disorder, especially if symptoms of other illnesses overlap with the symptoms of borderline personality disorder. For example, a person with borderline personality disorder may be more likely to also experience symptoms of depression, bipolar disorder, anxiety disorders, substance use disorders, or eating disorders.

Seek and Stick with Treatment

NIMH-funded studies show that people with borderline personality disorder who don’t receive adequate treatment are:

• More likely to develop other chronic medical or mental illnesses
• Less likely to make healthy lifestyle choices

Borderline personality disorder is also associated with a significantly higher rate of self-harm and suicidal behavior than the general public.

People with borderline personality disorder who are thinking of harming themselves or attempting suicide need help right away. 

If you or someone you know is in crisis, call the toll-free National Suicide Prevention Lifeline (NSPL) at 1-800-273-TALK (8255), 24 hours a day, 7 days a week. The service is available to everyone. The deaf and hard of hearing can contact the Lifeline via TTY at 1-800-799-4889. All calls are free and confidential. Contact social media outlets directly if you are concerned about a friend’s social media updates or dial 911 in an emergency. Read more on NIMH’s Suicide Prevention health topic page.

The treatments described on this page are just some of the options that may be available to a person with borderline personality disorder.

Psychotherapy

Psychotherapy is the first-line treatment for people with borderline personality disorder. A therapist can provide one-on-one treatment between the therapist and patient, or treatment in a group setting. Therapist-led group sessions may help teach people with borderline personality disorder how to interact with others and how to effectively express themselves.

It is important that people in therapy get along with, and trust their therapist. The very nature of borderline personality disorder can make it difficult for people with the disorder to maintain a comfortable and trusting bond with their therapist.

Two examples of psychotherapies used to treat borderline personality disorder include:

• Dialectical Behavior Therapy (DBT): This type of therapy was developed for individuals with borderline personality disorder. DBT uses concepts of mindfulness and acceptance or being aware of and attentive to the current situation and emotional state. DBT also teaches skills that can help:
• Control intense emotions
• Reduce self-destructive behaviors
• Improve relationships
• Cognitive Behavioral Therapy (CBT): This type of therapy can help people with borderline personality disorder identify and change core beliefs and behaviors that underlie inaccurate perceptions of themselves and others, and problems interacting with others. CBT may help reduce a range of mood and anxiety symptoms and reduce the number of suicidal or self-harming behaviors.

Read more on NIMH’s Psychotherapies health topic page.

Medications

Because the benefits are unclear, medications are not typically used as the primary treatment for borderline personality disorder. However, in some cases, a psychiatrist may recommend medications to treat specific symptoms such as:

• mood swings
• depression
• other co-occurring mental disorders

Treatment with medications may require care from more than one medical professional.

Certain medications can cause different side effects in different people. Talk to your doctor about what to expect from a particular medication. Read more in NIMH’s Mental Health Medicationshealth topic.

Other Elements of Care

Some people with borderline personality disorder experience severe symptoms and need intensive, often inpatient, care. Others may use some outpatient treatments but never need hospitalization or emergency care.

Therapy for Caregivers and Family Members

Families and caregivers of people with borderline personality disorder may also benefit from therapy. Having a relative or loved one with the disorder can be stressful, and family members or caregivers may unintentionally act in ways that can worsen their loved one’s symptoms.

Some borderline personality disorder therapies include family members, caregivers, or loved ones in treatment sessions. This type of therapy helps by:

• Allowing the relative or loved one develop skills to better understand and support a person with borderline personality disorder
• Focusing on the needs of family members to help them understand the obstacles and strategies for caring for someone with borderline personality disorder. Although more research is needed to determine the effectiveness of family therapy in borderline personality disorder, studies on other mental disorders suggest that including family members can help in a person's treatment.

Finding Help

More information about finding a health care provider or treatment for mental disorders in general is available on our Help for Mental Illness webpage.

Tips for Family and Caregivers

To help a friend or relative with the disorder:

• Offer emotional support, understanding, patience, and encouragement—change can be difficult and frightening to people with borderline personality disorder, but it is possible for them to get better over time
• Learn about mental disorders, including borderline personality disorder, so you can understand what the person with the disorder is experiencing
• Encourage your loved one who is in treatment for borderline personality disorder to ask about family therapy
• Seek counseling for yourself from a therapist. It should not be the same therapist that your loved one with borderline personality disorder is seeing

What are Clinical Trials?

Clinical trials are research studies that look at new ways to prevent, detect, or treat diseases and conditions, including borderline personality disorder. During clinical trials, treatments might be new drugs, new types of psychotherapy, new combinations of drugs, or new ways to use existing treatments. The goal of clinical trials is to determine if a new test or treatment works and is safe.

Although individual participants 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. Decisions about participating in a clinical trial are best made in collaboration with a licensed health professional.

To learn more about clinical trials, please visit the NIH Clinical Research Trials and You website. To find a clinical trial, visit ClinicalTrials.gov.

Free Brochures and Fact Sheets

• Borderline Personality Disorder: A brochure that offers basic information about borderline personality disorder, including signs and symptoms, treatment, and finding help. Also available en Español.
• 5 Action Steps for Helping Someone in Emotional Pain:Infographic presenting five steps for helping someone in emotional pain to prevent suicide. Also available en Español.
• Suicide in America: Frequently Asked Questions: Fact sheet can help you, or a friend or family member, learn about the signs and symptoms, risk factors and warning signs, and ongoing research about suicide and suicide prevention. Also available en Español.
• Warning Signs of Suicide: An infographic presenting behaviors and feelings that may be warnings signs that someone is thinking about suicide. Also available en Español.

Federal Resources

• Borderline Personality Disorder (MedlinePlus Medical Encyclopedia)
• Introduction to Co-Occurring Borderline Personality Disorder and Substance Use Disorders (Substance Abuse and Mental Health Services Administration)
• Personality Disorders (MedlinePlus - also en Español)

Research and Statistics

• Personality Disorders Clinical Trials: A listing of clinical trials funded by the National Institutes of Health being conducted across the country.
• Journal Articles: References and abstracts from MEDLINE/PubMed (National Library of Medicine).
• Statistics: Personality Disorders: Webpage listing information on the prevalence of personality disorder among adults.

Last Revised: December 2017

Unless otherwise specified, NIMH information and publications are in the public domain and available for use free of charge. Citation of the NIMH is appreciated. Please see our Citing NIMH Information and Publications page for more information.