Personality disorders are conditions in which an individual differs significantly from an average person, in terms of how they think, perceive, feel or relate to others.
Changes in how a person feels and distorted beliefs about other people can lead to odd behaviour, which can be distressing and may upset others.
Common features include:
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
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 experience other mental health problems, especially depression and substance misuse.
When and why personality disorders occur
Personality disorders typically emerge in adolescence and continue into adulthood.
They may be mild, moderate or severe, and people may have periods of "remission" where they function well.
Personality disorders may be associated with genetic and family factors. Experiences of distress or fear during childhood, such as neglect or abuse, are common.
Types of personality disorder
Several different types of personality disorder are recognised. They have been broadly grouped into one of three clusters – A, B or C – which are summarised below.
Cluster A personality disorders
A person with a cluster A personality disorder tends to have difficulty relating to others and usually shows patterns of behaviour most people would regard as odd and eccentric. Others may describe them as living in a fantasy world of their own.
An 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 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 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 fear and anxiety. They may show patterns of behaviour most people would regard as antisocial and withdrawn.
An example is avoidant personality disorder, where the person appears painfully shy, socially inhibited, feels inadequate and is extremely sensitive to rejection. The person may want to be close to others, but lacks confidence to form a close relationship.
How many people are affected?
Personality disorders are common mental health problems.
In England, it is estimated that around 1 in 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 severe problems may need specialist help for longer periods.
Many people recover from personality disorders over time. Psychological or medical treatment is sometimes helpful; sometimes support is all that is needed. This depends on the severity of the disorder and whether there are ongoing problems.
Some mild to moderate personality disorders improve withpsychotherapy.
Different types of psychological therapies have been shown to help people with personality disorders. However, there is no single approach that suits everyone and treatment should be tailored to the individual. Not all talking therapies are effective and it is essential they are delivered by a trained therapist.