Personality disorders

Your personality is the way you think, feel and behave. It’s influenced by your experiences, the environment you live in and characteristics you’re born with. Everyone’s personality is different and aspects of our personality might be difficult for us — or for other people.

If you have a personality disorder, certain ways you think, feel and behave have a significant and negative impact on different aspects of your daily life. You might have particular patterns of thoughts, feelings or beliefs that are difficult to change. These problems are likely to have been going on for a long time.

There’s a lot of debate about whether the definitions and diagnosis of types of personality disorders are helpful or reliable.

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What types of personality disorder are there?

Personality disorders are grouped into three categories (called clusters). Some people find it tempting to think that people they know have a personality disorder based on their experiences of their daily behaviour. However, you can only be diagnosed by a psychiatrist – and only if you meet specific criteria.

Types of eating disorder include:

  • Cluster A includes paranoid, schizoid and schizotypal personality disorders. If you have a cluster A disorder, you might have patterns of behaviour that other people may feel are particularly odd. You may have difficulty relating to other people – finding it hard to trust them or preferring to be alone.
  • Cluster B includes antisocial, borderline, narcissistic and histrionic personality disorders. If you have a cluster B disorder you probably find it difficult to control your feelings. You may move between positive and negative views of people around you and behave in ways that other people think are dramatic or unpredictable.
  • Cluster C includes avoidant, dependent and obsessive-compulsive personality disorders. If you have a cluster C disorder you are likely to have strong feelings of fear and anxiety that may lead you be very withdrawn.

Note that obsessive-compulsive personality disorder is different from obsessive-compulsive disorder.

What causes personality disorders?

We don’t have a clear understanding of why some people develop personality disorders. Research suggests that it’s likely to be a mix of factors.

  • Abuse, neglect, bullying and prolonged exposure to stress in childhood may be linked to the development of personality disorders.
  • Biological factors. Some research has found that people with a personality disorder diagnosis had certain small differences in their brain structure. But we don’t know whether these changes are caused by genes or by environmental factors.

What treatments are available for personality disorders?

There are no clear guidelines for the treatment of all personality disorders and more research is needed. Depending on your diagnosis and how much your life is being affected, you may be offered these treatments.

Talking therapies

The talking therapies you may be offered are:

  • cognitive behavioural therapy
  • psychotherapy
  • mentalisation-based therapy
  • dialectical behavioural therapy (a specific therapy developed for people with borderline personality disorder)

Not all of these treatments have strong evidence for their effectiveness, but your doctor may encourage you to try them to see how well they work.


You may be offered medication for a short time. Medication is usually offered if you’re in crisis or to help you manage other mental health problems. These may be antidepressants, antipsychotics or mood stabilisers.

For more information on treatments, see our information on common treatments and support.

Read more information on personality disorders on Rethink’s website.

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    • DSM-5 personality disorder factsheet. American Psychiatric Association, 2013.,
    • Personality disorders. BMJ Best Practice.
    • Diagnostic and statistical manual of mental disorders: fifth edition DSM-5. American Psychiatric Association, (2013)
    • Working with offenders with personality disorders - a practitioners guide. National Offender Management Service and NHS England, September 2015
    • Borderline personality disorder: recognition and management. NICE clinical guidelines CG78, January 2009
  • Produced by Clare Foster, freelance health editor, and Nick Ridgman, Head of Health Content, Bupa UK, September 2017
    Next review due September 2020

    Bupa UK expert reviewers:

    • Naomi Humber, Psychology Services Manager, EAP
    • Stuart Haydock, Resilience Lead, Health Clinics
    • Sarah Deedat, Head of Behaviour Change

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