Personality disorder - Definition 

Introduction 

Attitudes to mental health

Four people who've had mental health issues, including bipolar disorder, paranoid schizophrenia and personality disorder, talk about the negative reactions they faced and how they overcame them.

How common are the different types of personality disorder?

Mild personality disorders that do not seriously interfere with a person's ability to function socially are common. Severe disorders are rare and affect less than 2% of the population.

In a survey of 8,000 people chosen at random in the UK, the most common personality disorders (PDs) were:

  • obsessive compulsive PD, found in around 2% of people
  • schizoid PD
  • avoidant PD
  • paranoid PD
  • borderline PD 
  • antisocial PD, found in less than 1% of people

Many people with mild to moderate personality disorders seek treatment. People with more severe personality disorders, especially borderline and antisocial PD, may be more likely to come into contact with medical services but may be unwilling to seek treatment. This could be because they may not think there is anything wrong with them, or because they fear contact with health professionals.

Personality disorders are mental health conditions that affect how people manage their feelings and how they relate to other people.

Disturbances of feeling and distorted beliefs about other people can lead to odd behaviour, which can be distressing and which other people may find upsetting.

The main symptoms are:

  • being overwhelmed by negative feelings such as distress, anxiety, worthlessness or anger
  • avoiding other people and feeling empty and emotionally disconnected
  • difficulty managing negative feelings without self-harming (for example, abusing drugs and alcohol or taking overdoses) or, in rare cases, threatening other people 
  • odd behaviour
  • difficulty maintaining stable and close relationships, especially with partners, children and professional carers 
  • sometimes, periods of losing contact with reality

Symptoms typically get worse with stress.

People with personality disorders often have other mental health conditions, especially depression and substance misuse.

When and why personality disorders occur

Personality disorders typically start in adolescence and continue into adulthood.

They may be mild, moderate or severe, and people may have periods of 'remission' where they can function well.

Personality disorders are caused by a combination of genetic reasons and experiences of distress or fear during childhood, such as neglect or abuse.

Types of personality disorder

There are many different types of personality disorder. They can be broadly grouped into one of three clusters - A, B or C - which are summarised below. For a full list of the main types and signs of personality disorders, see Personality disorders - symptoms.

Cluster A personality disorders

A person with a cluster A personality disorder regards other people as alien and usually shows patterns of behaviour that most people would regard as odd and eccentric. Others may describe them as living in a fantasy world of their own.

An extreme example is paranoid personality disorder, where the person is extremely distrustful and suspicious.

Cluster B personality disorders

A person with a cluster B personality disorder struggles to regulate their feelings and often swings between positive and negative views of others. This can lead to patterns of behaviour that others describe as dramatic, unpredictable and disturbing.

An example is borderline personality disorder, where the person is emotionally unstable, has impulses to self-harm and has very intense and unstable relationships with others. 

Cluster C personality disorders

A person with a cluster C personality disorder struggles with persistent and overwhelming feelings of anxiety and fear. They tend to show patterns of behaviour that most people would regard as antisocial and withdrawn.

An example is avoidant personality disorder, where the person appears painfully shy, is socially inhibited, feels inadequate and is extremely sensitive to rejection. The person may want to be close to others, but lacks the confidence to form a close relationship.

How many people are affected?

Personality disorders are the commonest type of mental condition.

In England, it is estimated that around 1 in every 20 people has a personality disorder. However, many people have only mild conditions so only need help at times of stress (such as bereavement). Other people with more moderate conditions may need specialist help for longer periods.

Outlook

Most people recover from personality disorders with time and proper treatment. This depends on the severity of the disorder and whether there are other ongoing problems.

Most mild to moderate personality disorders can be successfully treated with a long-term course of psychological therapy (at least 12 months).

Different types of psychological therapies have been shown to help people with personality disorders. It is important to get the right therapy. Not all talking therapies are effective and it is essential that they are delivered by a trained therapist. For more information, see Personality disorder - treatment.

Last reviewed: 24/09/2010

Next review due: 24/09/2012