What is Borderline Personality Disorder?
Borderline personality disorder is a mental illness marked by an ongoing pattern of varying moods, self-image, and behavior. These symptoms often result in impulsive actions and problems in relationships. People with borderline personality disorder may experience intense episodes of anger, depression, and anxiety that can last from a few hours to days.
What are the signs and symptoms?
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 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 an 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.
What are the risk factors?
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 these people 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 the 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 it in their lifetime.
What treatments and therapies are available?
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 the 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 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 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
It 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 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 the condition 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.
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
- 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 Medications health 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 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
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 to ask about family therapy
- Seek counseling for yourself from a therapist. It should not be the same therapist that your loved one is seeing
National Institute of Mental Health (2019). Borderline Personality Disorder. Retrieved June 10, 2019 from