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Borderline personality disorder


Personality disorders are mental health conditions that can cause a range of distressing symptoms and patterns of abnormal behaviour, such as:

  • overwhelming feelings of distress, anxiety, worthlessness or anger
  • difficulty managing such feelings without self-harming, for example by abusing drugs and alcohol or taking overdoses
  • difficulty maintaining stable and close relationships
  • sometimes, periods of loss of contact with reality
  • in rare cases, threats of harm to others

Personality disorders typically start in adolescence and persist into adulthood. The cause is often a combination of genetic reasons and a harmful childhood experience. Personality disorders range from mild to severe.

What is borderline personality disorder (BPD)?

It used to be thought that people with borderline personality disorder (BPD) were at the ‘border’ between:

  • neurosis, where a person is mentally distressed but can still tell the difference between their imagination and reality
  • psychosis, where a person is unable to tell the difference between their imagination and reality, and may experience delusions (an unshakable belief in something that is implausible, bizarre or obviously untrue) and hallucinations (seeing or hearing things that other people do not)

Now it is known that this is not an accurate description. BPD is best understood as a disorder of mood and interpersonal function (how a person interacts with others).

BPD is one of the most commonly seen personality disorders by GPs.

Although BPD is said to be more common in women, this is probably because fewer men seek treatment.

How does BPD develop?

The causes of BPD are unclear. However, as with many mental health conditions, BPD appears to be the result of a combination of genetic and environmental factors.

Traumatic events that occur during childhood are a major risk factor for developing BPD. An estimated 8 out of 10 people with BPD experience parental neglect or physical, sexual or emotional abuse during their childhood. For more information, see Borderline personality disorder - causes.


BPD is a serious condition because many people with the condition will self-harm and attempt suicide. It is estimated that 60-70% of people with BPD will attempt suicide at some point in their life, and 10% will succeed.

However, the outlook for people with BPD is reasonably good as long as they are patient and willing to commit to long-term treatment.

Treatment for BPD usually involves a range of individual and group psychological therapies. Effective treatment usually lasts at least a year (see Borderline personality disorder – treatment for more information).

A study carried out in 2010 found that half of all people with BPD will completely recover and around 80% of people will remain mostly free of symptoms for at least four years.

Additional treatment is recommended for people whose symptoms return.

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Borderline personality disorder (BPD) can cause a wide range of symptoms. These can be broadly grouped into four main areas:

  • emotional instability (the psychological term for this is affective disturbance)
  • disturbed patterns of thinking (the psychological term for this is disturbed cognition)
  • impulsive behaviour
  • intense but unstable relationships with others

Each of these areas is described in more detail below.

Affective disturbance

If you have BPD, you may experience a range of often intense negative emotions, such as:

  • rage
  • sorrow
  • shame
  • panic
  • terror
  • long-term feelings of emptiness and loneliness

You may have severe mood swings over a short space of time. It is common for people with BPD to feel suicidal with despair and then feel reasonably positive a few hours later. Some people feel better in the morning and some in the evening. The pattern varies, but the key sign is that your moods swing in unpredictable ways.

Disturbed cognition

There are three levels of disturbed thinking that can affect people with BPD, which are ranked according to severity:

  • Upsetting thoughts, such as thinking you are a terrible person or feeling you do not exist. You may not be sure of these thoughts and may seek reassurance that they are not true.
  • Brief episodes of strange thoughts, such as hearing voices for minutes at a time. These may often feel like instructions to harm yourself or others. You may or may not be certain whether these are real.
  • Prolonged episodes of highly abnormal thoughts, where you might experience both prolonged hallucinations (such as hearing a voice constantly in your head) and painful or distressing beliefs that no one can talk you out of (such as believing your family are secretly trying to kill you). These types of thoughts are psychotic thoughts, and they are a sign that something is really wrong. It is important to get help if you are struggling with psychotic thoughts.

Impulsive behaviour

If you have BPD, there are two main types of impulses that you may find extremely difficult to control:

  • An impulse to self-harm, such as cutting your arms with razors or burning your skin with cigarettes. In severe cases, especially if you also feel intensely sad and depressed, this impulse can lead to feeling suicidal and you may attempt suicide.
  • A strong impulse to engage in reckless and irresponsible activities, such as binge drinking, drug abuse, going on a spending or gambling spree or having unprotected sex with strangers. Impulsive behaviours are especially dangerous when people are in brief psychotic states, because they may be much more likely to act impulsively if their judgement is impaired.

Unstable relationships

If you have BPD, you may experience other people as either abandoning you when you most need them or getting too close and smothering you.

When people fear abandonment, they may experience intense anxiety and anger. They may make frantic efforts to prevent being left alone, such as:

  • constantly texting or phoning a person
  • suddenly calling that person in the middle of the night
  • physically clinging on to that person and refusing to let go
  • making threats that they will harm or kill themselves if that person ever leaves them

This often has the opposite effect and tends to make people draw away from you or reject you.

Alternatively, you may feel that other people are smothering, controlling or crowding you, which also provokes intense fear and anger.

You may then respond by acting in ways to make people go away, emotionally withdrawing or rejecting or using verbal abuse.

These two patterns will probably result in an unstable ‘love-hate’ relationship with certain people.

For example, one moment you may think your boyfriend or girlfriend is the best person in the world and the love of your life. But when they do something minor to upset you, you suddenly feel intense rage and hatred towards them.

Many people with BPD seem to be stuck with a very rigid ‘black-white’ view of relationships. Either a relationship is perfect and that person is wonderful, or the relationship is doomed and that person is terrible. You can see this as another type of thinking distortion, because in reality, relationships are not black or white. People with BPD cannot always see this. They seem to be unable or unwilling to accept any sort of ‘grey area’ in their personal life and relationships.

For many people with BPD, emotional relationships (including relationships with professional carers) involve ‘Go away!/Please don’t go’ states of mind, which is confusing for them and their partners. Sadly, this can often lead to break-ups.

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Most experts agree that there is not one single cause of borderline personality disorder (BPD). It is likely that the condition is caused by a combination of different factors, including:

  • Genetics. The genes you inherit from your parents may make you more likely to develop BPD.
  • Neurotransmitters. These are ‘messenger chemicals’ used by your brain to transmit signals between brain cells. It has long been known that changes in the levels of certain neurotransmitters can have a powerful effect on mood and behaviour.
  • Neurobiology. This term describes the structure and function of your brain and nervous system. It appears that some people with BPD have a number of regions in the brain with abnormal structure and function.
  • Environmental factors. Events that happened in your past, such as your relationship with your family, appear to play an important role in BPD.

These four factors are explained in more detail below.


Currently, the strongest evidence that genetics may play a role in BPD is research that studied twins.

One study found that if one identical twin had BPD, there was a two-in-three chance that the other identical twin would also have BPD.

However, these results have to be interpreted with caution and there is no evidence that there is a gene for BPD.

Firstly, you may be more likely to develop certain personality traits. For example, you may inherit from your parents a tendency to be aggressive and emotionally unstable, rather than BPD itself.

Secondly, most identical twins grow up in the same household and in the same family environment, so they will share many environmental factors.


It is thought that many people with BPD either have reduced levels of a neurotransmitter called serotonin in their brain, or their brain does not react to serotonin in the right way.

Low levels of serotonin activity in the brain have been linked to depression, aggression and an inability to control destructive urges.

There is also some limited evidence that some people with BPD also have low levels of two neurotransmitters, called dopamine and noradrenaline. Low levels of these two neurotransmitters may cause emotional instability.


Researchers have used MRI scanners to study the brains of people with BPD. MRI scans use strong magnetic fields and radio waves to produce a detailed image of the inside of the body.

The scans revealed that in many people with BPD, three parts of the brain were either smaller than expected or had unusual levels of activity. These parts were:

  • the amygdala, which plays an important role in regulating emotions, especially the more ‘negative’ emotions such as fear, aggression and anxiety
  • the hippocampus, which helps regulate behaviour and self-control
  • the orbitofrontal cortex, which is involved in planning and decision making

Problems with these parts of the brain may well contribute to the symptoms of BPD.

The development of these parts of the brain is affected by your early upbringing (see below). These parts of your brain also are responsible for mood regulation, which may account for some of the problems that people with BPD have in close relationships.

Environmental factors

A number of environmental factors seem to be common and widespread among people with BPD. These include:

  • being a victim of emotional, physical or sexual abuse
  • being exposed to chronic fear or distress as a child
  • being neglected by one or both parents
  • growing up with another family member who had a serious mental health condition, such as bipolar disorder or a drink or drug misuse problem

A person's relationship with their parents and family has a strong influence on how they come to see the world and what they believe about other people.

Unresolved fear, anger and distress from childhood can lead to a variety of distorted adult thinking patterns, such as idealising others, expecting others to be a parent to you, expecting other people to bully you and behaving as if other people are adults and you are not.

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If you are concerned that you have a borderline personality disorder (BPD), make an appointment with your GP.

Your GP will probably ask about how you feel, your recent behaviour and what sort of impact your symptoms have had on your quality of life.

This is to rule out other more common mental health conditions, such as depression, and to make sure there is no immediate risk to your health and wellbeing.

Community mental health team

If your GP suspects that you may have BPD, you will probably be referred to your local community mental health team (CMHT) for a more in-depth assessment. Ask if the service you are being referred to has experience of working with personality disorders.

CMHTs help people with complex mental health conditions such as BPD. However, they often focus only on people with psychotic disorders. In some areas, there are complex needs services that may be better placed to help you.

Your assessment will probably be carried out by a specialist in personality disorders, most likely a psychologist or psychiatrist.


A checklist of internationally recognised criteria is used to diagnosis BPD. A diagnosis can usually be made if you answer yes to five or more of the following questions:

  • Has an intense fear of being left alone caused you to act in ways that, on reflection, seem out of the ordinary or extreme, such as constantly phoning somebody (but not including self-harming or suicidal behaviour)?
  • Do you have a pattern of intense and unstable relationships with other people that switch between thinking you love that person and they are wonderful to hating that person and thinking they are terrible?
  • Do you ever feel you do not really have a strong sense of your own self and are unclear about your self-image?
  • Do you engage in impulsive activities in two areas that are potentially damaging, such as unsafe sex, drug abuse or reckless spending (but not including self-harming or suicidal behaviour)?
  • Have you made repeated suicide threats or attempts in your past and engaged in self-harming?
  • Do you have severe mood swings, such as feeling intensely depressed, anxious or irritable, which last from a few hours to a few days?
  • Do you have long-term feelings of emptiness and loneliness?
  • Do you have sudden and intense feelings of anger and aggression and often find it difficult to control your anger?
  • When you find yourself in stressful situations, do you have feelings of paranoia, or do you feel like you are disconnected from the world or from your own body, thoughts and behaviour?

Involving your family

Once a diagnosis of borderline personality disorder (BPD) has been confirmed, it is recommended that you tell close family, friends and people you trust about the diagnosis.

There are several reasons for this.

Many of the symptoms of BPD affect your relationships with people close to you, so involving them in your treatment may make them aware of your condition and make your treatment more effective.

Your family and friends will be able to remain alert for any behaviour that may indicate you are having a crisis.

Your family and friends may benefit from local support groups and other services for people in a relationship with a person with BPD.

However, the decision to talk about your condition is entirely your own, and your confidentiality will be respected at all times.

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Community mental health teams

Most people with a borderline personality disorder (BPD) are treated by community mental health teams (CMHTs). The goal of the CMHT is to provide day-to-day support and treatment while trying to ensure that you have as much independence as possible.

A CMHT can be made up of:

  • social workers
  • community mental health nurses (who have specialist training in mental health conditions)
  • pharmacists
  • counsellors and psychotherapists
  • psychologists and psychiatrists (the psychiatrist is usually the senior clinician in the team)

Care programme approach (CPA)

If your symptoms are moderate to severe, you will probably be entered into a treatment process known as a care programme approach (CPA).

A CPA is essentially a way of ensuring you receive the right treatment for your needs. There are four stages:

  • assessment of your health and social needs
  • care plan, created to meet your health and social needs
  • appointment of a care co-ordinator (keyworker), usually a social worker or nurse and your first point of contact with other members of the CMHT
  • reviews, where your treatment is regularly reviewed and any necessary changes to the care plan can be agreed


Treatment for BPD usually involves some type of psychological therapy, also known as psychotherapy. There are lots of different types of psychotherapy, but they all involve taking time to help you get a better understanding of how you think and feel.

As well as listening and discussing important issues with you, the psychotherapist can suggest ways to resolve problems and, if necessary, help you change your attitudes and behaviour. Therapy for BPD aims to help people get a better sense of control over their feelings and thoughts.

Psychotherapy for BPD should only be delivered by a trained professional. They will usually be a psychiatrist, psychologist or other trained mental health professional. Do not be afraid to ask about their experience.

The Department of Health recently looked at the best treatments for BPD. It recommends:

  • treatment that lasts at least 12-18 months
  • dialectical behaviour therapy for people who really struggle with self-harming behaviours
  • mentalisation-based therapy, which is a mixture of group and individual reflection
  • therapeutic communities and structured group therapy programmes

These therapies are described below.

There is no evidence that any other types of therapy are particularly helpful. If you have a history of sexual abuse in childhood, it may not be a good idea to start with individual work, which can be upsetting. It may be better to start in a group and learn to manage horrible feelings safely before doing individual work.

The psychotherapy you choose may be based on a combination of personal preference and the availability of specific treatments in your local area.

Dialectical behaviour therapy (DBT)

Dialectical behaviour therapy (DBT) is a type of therapy that has been specifically designed to treat people with BPD.

DBT is based on the idea that two important factors contribute towards BPD:

  • You are particularly emotionally vulnerable, for example low levels of stress make you feel extremely anxious.
  • You grew up in an environment where your emotions were dismissed by those around you. For example, a parent may have told you that you had no right to feel sad or you were just ‘being silly’ if you complained of feelings of anxiety or stress.

These two factors may cause you to fall into a vicious circle. You experience intense and upsetting emotions, yet feel guilty and worthless for having these emotions. Because of your upbringing, you think that having these emotions makes you a bad person. These thoughts then lead to further upsetting emotions.

The goal of DBT is to break this cycle. This is done by introducing two important concepts:

  • validation: accepting that your emotions are valid, real and acceptable
  • dialectics: a school of philosophy that says most things in life are rarely ‘black or white’ and it is important to be open to ideas and opinions that contradict your own

The DBT therapist will use both concepts to try and bring about positive changes in your behaviour.

For example, the therapist could accept (validate) that feelings of intense sadness cause you to self-harm, and that behaving in such a way does not make you a terrible and worthless person.

But then the therapist would attempt to challenge the assumption that self-harming is the only way to cope with feelings of sadness.

The ultimate goal of DBT is to help you ‘break free’ of seeing the world, your relationships and your life in a very narrow, rigid way that leads you to engage in harmful and self-destructive behaviour.

DBT is made up of four components:

  • weekly individual sessions, in which you discuss ways you can help control and improve your behaviour
  • weekly group sessions, where you interact with other people with BPD as well as a number of different therapists and discuss ways you can all improve your emotional control and your relationships with others
  • out-of-hours telephone contact, where you are given a contact number for your therapist so you can speak to them if you have a crisis (severe worsening of your symptoms)
  • a therapist consultation group, which does not involve you directly, but where the therapists discuss issues that may have arisen with the treatment of their clients (you should not see this as the therapists ‘talking behind your back’)

DBT is based on teamwork. You will be expected to work with your therapist and the other people in your group sessions. In turn, the therapists work together as a team, and the consultation group is part of the process.

There are four main stages in a course of DBT:

  • stage 1: helping you control your behaviour and refrain from self-destructive and harmful behaviour
  • stage 2: helping you tolerate your negative emotions while also experiencing positive emotions more fully
  • stage 3: helping you focus on difficulties affecting your everyday life
  • stage 4: helping you gain more happiness and joy out of your everyday life

It is not necessary to complete all stages to combat the symptoms of BPD.

Also, due to a lack of trained therapists, many health boards only provide the first stage of treatment free of charge on the NHS. If you wish to receive the entire course, you may have to pay a fee.

DBT has proved particularly effective in treating women with DPB who have a history of self-harming and suicidal behaviour. It has been recommended by the National Institute for Health and Clinical Excellence (NICE) as the first treatment for these women to try.

Mentalisation-based therapy (MBT)

Another type of long-term psychotherapy that can be used to treat BPD is mentalisation-based therapy (MBT).

MBT is based on the concept that people with BPD have a poor capacity to mentalise.

Mentalisation is the ability to think about thinking. This means examining your own thoughts and beliefs, and assessing whether they are useful, realistic and based on reality.

For example, many people with BPD will have a sudden urge to self-harm and will then fulfil that urge without questioning it. They lack the ability to ‘step back’ from that urge and say to themselves, ‘That is not a healthy way of thinking and I am only thinking this way because I am upset.’

Another important part of mentalisation is to recognise that other people have their own thoughts, emotions, beliefs, wishes and needs, and your interpretation of other people’s mental states may not necessarily be correct. In addition, you need to be aware of the potential impact your actions will have on other people’s mental states.

For example, a person with BPD meets a close friend for lunch because that friend has recently lost her grandmother. But during lunch, the person with BPD spends the entire time talking about their problems. So the close friend leaves abruptly as she is fed up of being ignored and not receiving the emotional support she was expecting.

This causes the person with BPD to fly into a rage at what they perceive to be a snub. They lack the ability to recognise that their friend has their own set of emotional needs and that their actions had a negative impact on their friend.

The goal of MBT is to improve your ability to recognise your own and others’ mental states, and learn to ‘step back’ from your thoughts about yourself and others and examine them to see if they are valid.

Initially, MBT is usually delivered in a hospital, where you would stay as an inpatient. The treatment usually consists of daily individual sessions with a therapist and group sessions with other people with BPD.

The therapist will work with you by asking you questions and setting tasks that encourage you to mentalise.

A course of MBT usually lasts around 18 months. Some hospitals and specialist centres encourage you to remain as an inpatient during this time. Other hospitals and centres may recommend that you leave the hospital after a certain period of time but remain being treated as an outpatient, where you visit the hospital regularly.

Therapeutic communities (TCs)

Therapeutic communities (TCs) are structured environments where people with a range of complex psychological conditions and needs come together to interact and take part in therapy.

TCs are designed to help people with long-standing emotional problems and a history of self-harming by teaching them the skills needed to interact socially with other people.

Most TCs are residential, such as in large houses, where you stay for around one to four days a week.

As well as taking part in individual and group therapy, you would be expected to do other activities designed to improve your social skills and self-confidence, such as:

  • household chores
  • meal preparation
  • games, sports and other recreational activities
  • regular community meetings, where people discuss any issues that have arisen in the community

TCs are run on a democratic basis. This means that each resident and staff member has a vote on how the TC should be run, including whether a person is suitable for admission to that community.

If your care team advises that you may benefit from spending time in a TC, it does not automatically mean the TC will allow you to join.

Many TCs set guidelines on what is considered acceptable behaviour within the community, such as no drinking alcohol, no violence to other residents or staff, and no attempts at self-harming. Those who break these guidelines are usually told to leave the TC.

While some people with BPD have reported that the time spent in a TC helped their symptoms, there is not yet enough evidence to tell whether TCs would help everyone with BPD.

Also, because of their often strict rules on behaviour, a TC would probably not be suitable for you if you were having significant difficulties controlling your behaviour.

Treating a crisis

You will probably be given several telephone numbers to use if you think you may be experiencing a crisis (when symptoms are particularly severe and you have an increased risk of self-harm).

One of these numbers is likely to be your community mental health nurse. Other numbers may include an out-of-hours number for social workers and your local crisis resolution team (CRT).

CRTs treat people with serious mental health conditions who are currently experiencing an acute and severe psychiatric crisis, which would require hospitalisation without the involvement of the team. An example of a severe psychiatric crisis would be a suicide attempt.

Often, people with BPD find that simply talking to somebody who understands their condition can help bring them out of a crisis.

In a small number of cases, you may be given a short course of medication, such as a tranquiliser, to calm your mood. This medication is usually prescribed for seven days.

If your symptoms are particularly severe and it is thought that you pose a significant risk to your own health, you will be involuntarily detained under the Mental Health Act at a secure mental health facility. This will be for as short a time as possible, and you should be able to return home once your symptoms have improved.

Is medication helpful?

Experts are divided over whether medication is helpful. Most therapists agree that if medication is prescribed, it should be on a short-term basis if possible.

Currently, no medication is licensed to treat borderline personality disorder.

Medications are normally only used if you have another associated mental health condition, such as depression, anxiety disorder or bipolar disorder.

For more information, see the Health A-Z pages on treating depressionanxiety disorder and bipolar disorder.

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