Mentalization: A Failing Ability in Borderline Personality Disorder

In borderline personality disorder there's a partial failure of mentalization. This means that sufferers are unable to understand their internal world and that of others. We explain what it implies and why it happens.
Mentalization: A Failing Ability in Borderline Personality Disorder

Written by Elena Sanz

Last update: 11 November, 2022

In your everyday life, the way you conduct yourself is based on the behaviors of others. Indeed, what other people say and do and how you react are key to your interactions. However, for your personal and social worlds to work, it’s essential to look further and understand that all of your behavior is a function of your own previous mental states (your thoughts and emotions). This is known as mentalizing ability, and when it fails, significant difficulties can arise.

Mentalization allows you to understand that the actions of others correspond to their own internal processes and identify what mental content is influencing them. For example, if your partner is emotionally distant, you understand that they might be stressed about work. Or, if you lose your temper, you realize that anxiety has taken you over because a certain situation has overwhelmed you.

Having this information is crucial. Without it, you’d be left at the mercy of your emotions and impulses that you wouldn’t understand and would be unable to control. This would cause you intense discomfort and profoundly affect your relationships. This is exactly what happens in borderline personality disorder (BPD).

friends arguing
People with BPD have difficulty understanding both their own internal states and those of others.

Mentalization

Mentalization is the function through which you reflect on your internal states (thoughts, emotions, desires, needs) and those of others, and on how these influence your behavior.

You weren’t born with this ability, but you developed it through socialization and the bond with your first reference figures, the adults who raised you.

When caregivers are able to connect with the infant, care for them, mirror their emotions, and respond correctly to their needs, the process goes smoothly. On the other hand, if a caregiver is emotionally disconnected from the infant and doesn’t respond to their interactions consistently or exercise their regulation function, the child won’t learn to regulate and relate to their emotions either.

The importance of attachment

In the latter case, the infant will develop an insecure attachment. Furthermore, they won’t acquire the capacity for mentalization. This results in a series of consequences. The following are the most relevant:

  • They may experience somatizations. These are emotions that haven’t been adequately identified, expressed, and regulated. They manifest themselves in the form of bodily symptoms.
  • They’re unable to recognize, name, understand or manage their emotions. Moreover, they’re unaware of the emotions they experience and don’t know how to connect with their needs. Consequently, it’s really difficult for them to make decisions and they may feel constantly empty.
  • It’s difficult for them to infer the internal states of other people. In effect, they don’t develop adequate empathy. For this reason, it’s common for them to misunderstand the actions of others. In fact, they may think they’re due to something that they’ve done.
  • They don’t feel as if they own their own thoughts and feelings. They have no control in this regard. Instead, they feel overwhelmed and hijacked by internal processes and they act impulsively.
  • Their mental states tend to be subjective representations of the world and don’t fully correspond to reality. Therefore, the impact of distressing or self-critical thoughts is much greater.

Mentalization and borderline personality disorder

Borderline personality disorder (BPD) is a complex and serious mental condition. It’s mainly characterized by difficulty in regulating emotions and controlling impulses, as well as instability in social relationships and self-image.

Research has found that, in this population, recurrent suicidal behavior is present in 69-80 percent of cases, and the discomfort experienced is intense. For this reason, it’s essential to have a good understanding of the disorder and a series of effective therapeutic approaches available.

According to psychologists, Peter Fonagy and Anthony Bateman, the failure in the ability to mentalize lies behind the main symptoms of BPD. They suggest that sufferers didn’t have caregivers who were sensitive, connected, and capable of regulating themselves and teaching their children to do the same. Therefore, they didn’t properly develop this ability.

The role of attachment

For the establishment of a secure attachment, and to encourage mentalization, the adult caregiver must be able to reflect or mirror the emotions that the child expresses. They must do it in a marked and consistent way so that the child can integrate it. Otherwise, they’ll be unable to elaborate in their mind a representation of those emotions. They won’t be able to establish a link between their mental states and the reality they see around them.

As a consequence, the child will experience difficulty in identifying and connecting with their mental states, as well as understanding and managing them. Nor will they be able to adequately interpret other emotions. For this reason, they become overwhelmed by emotions and impulses. Consequently, they suffer great psychological discomfort and difficulties in their interpersonal relationships.

However, they don’t suffer from a complete inability to mentalize in all situations. It mainly occurs in those of high emotional activation and in the context of intense emotional relationships. In fact, it’s been observed that, at these moments, a hyperactivation of attachment occurs. This partially suppresses the ability to mentalize.

Sad girl, representing the failure of mentalization in an insecure attachment
Children who are overwhelmed by their emotions and impulses often have problems with the ability to mentalize.

Mentalization-based therapy

In light of these findings, an intervention strategy focused on alleviating the deficit has been designed. The therapy is based on mentalization. It promotes the ability to carry out this reflective function. It teaches impulse control and emotion regulation and improves social skills.

There are multiple mental disorders in which mentalization fails to some degree. Nevertheless, it’s in borderline personality disorder that this intervention has been shown to be most necessary and effective.

It might interest you...
Living with Borderline Personality Disorder
Exploring your mind
Read it in Exploring your mind
Living with Borderline Personality Disorder

BPD is one of the personality disorders that makes day to day life more difficult...those Living with Borderline Personality Disorder - find in our...

 



  • Bateman, A., & Fonagy, P. (2010). Mentalization based treatment for borderline personality disorder. World psychiatry9(1), 11.
  • Sánchez Quintero, S., & Vega, I. D. L. (2013). Introducción al tratamiento basado en la mentalización para el trastorno límite de la personalidad. Acción psicológica10(1), 21-32.