Borderline Personality Disorder

What is borderline personality disorder?

Borderline personality disorder is a mental illness that severely impacts a person’s ability to regulate 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 to manage the symptoms of borderline personality disorder. Learn more about the disorder, how it’s diagnosed, and how to find support.

What are the signs and symptoms?

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 abuse, reckless driving, and binge eating. Please note: 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 may experience all of these symptoms. The severity, frequency, and duration of symptoms depend on the person and their illness.

What causes borderline personality disorder?

Researchers aren’t sure what causes borderline personality disorder, but studies suggest that genetic, environmental, and social factors may increase the risk of developing it. These factors may include:

• Family history: People who have a close family member (such as a parent or sibling) with the illness may be at a higher risk of developing borderline personality disorder.
• Brain structure and function: Research shows that people with borderline personality disorder may have structural and functional changes in the brain, especially in the areas that control impulses and emotion regulation. However, the studies do not demonstrate whether these changes were risk factors for the illness or if such changes were 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 hardship during childhood. Others may have been exposed to unstable, invalidating relationships or conflicts.

Although these factors may increase a person’s risk, it doesn’t mean it is certain that they’ll develop borderline personality disorder. Likewise, people without these risk factors may develop the disorder in their lifetime.

How is borderline personality disorder diagnosed?

A licensed mental health professional—such as a psychiatrist, psychologist, or clinical social worker—who is experienced in diagnosing and treating mental disorders can diagnose borderline personality disorder based on a thorough interview and a discussion about symptoms. A careful and thorough medical exam also can help rule out other possible causes of symptoms. In diagnosing the illness, providers will discuss a person’s symptoms and ask about family medical histories, including histories of mental illness.

Borderline personality disorder is usually diagnosed in late adolescence or early adulthood. Occasionally, a person younger than age 18 may be diagnosed with borderline personality disorder if symptoms are significant and last at least a 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 diagnose and treat borderline personality disorder, especially if symptoms of other illnesses overlap with symptoms of the disorder. 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 abuse, or eating disorders.

How is borderline personality disorder treated?

Borderline personality disorder historically has been viewed as challenging to treat. But with newer, evidence-based treatment, many people with this disorder experience fewer and less severe symptoms, improved functioning, and better quality of life. It is important for patients with borderline personality disorder to receive treatment from a licensed mental health professional. Other types of treatment, or treatment from a provider who is not appropriately trained, may be ineffective or dangerous.

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

It is important to seek—and stick with—treatment.

Studies funded by the National Institute of Mental Health (NIMH) indicate that individuals with borderline personality disorder who don’t receive adequate treatment are more likely to develop other chronic medical or mental illnesses and are less likely to make healthy lifestyle choices.

Psychotherapy

Psychotherapy, sometimes called “talk therapy,” is the first-line 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 individuals in group settings. Group sessions may help teach people with borderline personality disorder to interact with others and express themselves effectively.

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

• Dialectical Behavior Therapy (DBT): This treatment was developed specifically for individuals 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 control intense emotions, reduce self-destructive behaviors, and improve relationships.
• Cognitive Behavioral Therapy (CBT): This treatment can help people identify and change core beliefs and behaviors that come from inaccurate perceptions of themselves and others and problems interacting with others. It may help people reduce mood swings and anxiety symptoms and may reduce the number of self-harming or suicidal behaviors.

Read more on NIMH’s psychotherapies webpage.

Medications

Because the benefits of prescription medication for borderline personality disorder are unclear, medications aren’t typically used as the primary way to treat the illness. However, 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 from more than one medical professional.

Medications also can sometimes cause side effects in some people. Talk to your provider about what to expect from a particular medication. Read more on NIMH’s mental health medications webpage.

Therapy for Caregivers and Family Members

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.

Although 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 the relative or loved one to develop skills to 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 the disorder.

How can I help a friend or family member with borderline personality disorder?

Here are some ways to help a friend or relative with the 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 learn more about clinical trials studying borderline personality disorder?

NIMH supports a wide range of research, including clinical trials that look at new ways to prevent, detect, or treat diseases and conditions, including borderline personality disorder. 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 clinical trials with patients and healthy volunteers. Talk to a health care provider about clinical trials, their benefits and risks, and whether one is right for you. For more information, visit NIMH’s clinical trials webpage.

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For More Information

Medline Plus  (National Library of Medicine) (en español )

ClinicalTrials.gov  (en español )

U.S. DEPARTMENT OF HEALTH AND HUMAN SERVICES
National Institutes of Health
NIH Publication No. 22-MH-4928
Revised 2022