Information for the public

Borderline personality disorder

Borderline personality disorder

Borderline personality disorder is a condition that affects a person's thoughts, emotions and behaviour. It is not usually diagnosed before the age of 18 but symptoms can be recognised in younger people. 'Borderline' was originally used by psychiatrists to suggest that the condition was thought to be on the 'border' of other psychiatric problems. Some experts think that this is no longer the most appropriate term to use.

The symptoms of borderline personality disorder include:

  • having emotions that are up and down (for example, feeling confident one day and feeling despair another), with feelings of emptiness and often anger

  • difficulty in making and maintaining relationships

  • having an unstable sense of identity, such as thinking differently about yourself depending on who you are with

  • taking risks or doing things without thinking about the consequences

  • harming yourself or thinking about harming yourself (for example, cutting yourself or overdosing)

  • fearing being abandoned or rejected or being alone

  • sometimes believing in things that are not real or true (called delusions) or seeing or hearing things that are not really there (called hallucinations).

A person diagnosed with borderline personality disorder will have most of these symptoms and they will have a significant impact on their life.

People with borderline personality disorder come from many different backgrounds, but most will have suffered some kind of trauma or neglect as children.

Just under 1% of people have borderline personality disorder. Some of those people may also have other conditions such as depression, anxiety(feelings of worry or fear that can be difficult to control), an eating disorder, post-traumatic stress disorder or bipolar disorder, or problems with drugs and alcohol.

Although some people may have borderline personality disorder for a long time, many do recover from the condition.