Mentalization-Based Treatment: Effective Care for Borderline Personality Disorder

Developed to treat people with BPD, MBT can be learned quickly to help more people receive the help they need

Mentalization-based treatment (MBT) has been proven to be beneficial in the management of borderline personality disorder (BPD). MBT encourages an individual to focus on how their mental states affect their own behavior, as well as the behavior of others.

MBT is a form of therapy that does not require extensive additional training for providers. Mental health professionals can learn this therapy in a relatively short amount of time to help more people receive the care they need.

So how can you discover if MBT would work for you, your patients, or a loved one? And how can you find a provider that offers MBT as a treatment option?

Keep Reading To Learn

  • Why MBT is effective for BPD
  • How MBT works
  • Who can provide MBT—and how to find care

What Exactly Is Mentalization?

Mentalization refers to the ability to understand our own thoughts and feelings, as well as the thoughts and feelings of other people.

One way we might mentalize is when we shop for a present and imagine a gift the recipient would like. The success of this prediction depends on our sense of what that person is like.

Or we might have a difficult conversation with someone and mentalize what is going through their mind. They may have a different point of view or pick up on things that we might initially have missed. Using mentalization in this way can help us so we don’t become too defensive about our own position.

When we mentalize well, our lives become easier in many ways—and when we stop mentalizing, our personal interactions can become challenging and intense. We can make inaccurate assumptions about other people’s motives and behavior. Close relationships can seem untrustworthy and become a source of stress rather than support.

MBT focuses on the patient’s present, rather than past, experiences. The therapy does not aim to provide the patient with new insight. Instead, MBT’s primary goal is to enhance a person’s ability to reflect on their own thoughts, feelings, and behavior, as well as those of others.

We all struggle with mentalization at times. Mentalization can be challenging when we experience intense emotions or feel unsure of where we stand with others. Sometimes we tend to get carried away by our emotions or we shut down.

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MBT is especially helpful in the treatment of borderline personality disorder and McLean’s Dr. Lois Choi-Kain helps us understand more about BPD

The Link Between Mentalization and Borderline Personality Disorder

People living with borderline personality disorder experience emotional dysregulation more frequently than others and may find it difficult to mentalize with these intense emotions or reactions. They can also struggle with feelings of paranoia and suspicion about the intentions of other people.

As a result of impaired mentalization skills, individuals living with BPD may experience instability in their relationships and self-image.

Anthony Bateman and Peter Fonagy, the creators of MBT, based this form of therapy on the idea that borderline personality disorder is primarily a disorder of mentalization. Because of this, MBT aims to help people living with BPD by teaching them to understand their own internal experiences, as well as the emotional experiences of those with whom they are interacting.

Losing Sight of Mentalization

According to Bateman and Fonagy, people with BPD lose their ability to mentalize under specific circumstances. These include, but aren’t limited to, the following.


By attaching to another person too quickly, a person with BPD can idealize the other person in the relationship and become overly or prematurely trusting.

However, their struggle to understand their own mental states and those of others leaves the person vulnerable to severe disappointment or anger when their needs seem to be unmet. People who relate to others this way tend to have a history of volatile relationships.


When experiencing emotional distress, someone with BPD may also distance themselves emotionally.

Although they may appear calm during such times, these individuals are experiencing intense emotional pain. They may seem to be mentalizing, but instead are intellectualizing a situation to avoid the feelings associated with it. People who relate to others in this way may avoid close relationships and live isolated lives.

Mixed Hyperactivation and Deactivation

People with BPD most often use a combination of hyperactivation and deactivation when relating to others. This creates rapid shifts in the direction and quality of their mentalization, which may seem unpredictable and chaotic to themselves and others.

Using MBT, people with BPD can improve interpersonal and relationship skills while reducing self-destructive behaviors. Improved mentalization may also lead to a more coherent understanding of oneself as a person.

Understanding the Mentalization-Based Treatment Process

MBT was developed to be quickly learned and easily implemented by a variety of mental health professionals, including psychiatrists, psychologists, social workers, nurses, and mental health counselors. Licensed mental health professionals can learn MBT in a three-day training followed by expert clinical supervision.

Mentalization-based treatment focuses on stabilizing a patient’s sense of self and on sustaining mentalization with an interpersonal focus.

Before Starting Treatment: Evaluation

Before starting treatment, the patient meets with a mental health professional. The clinician conducts an assessment of the mentalizing vulnerabilities which may be related to the problems for which the patient is seeking help.

During the evaluation, the therapist works with the patient to understand their issues with mentalization, as well as the types of situations in which these challenges are most likely to occur.

The therapist asks about the patient’s close relationships. Together, the clinician and patient explore if the patient uses the hyperactivation, deactivation, or mixed strategies mentioned above. They try to understand the circumstances that trigger key emotional, interpersonal, and behavioral patterns that cause the patient difficulty.

The therapist also tries to gain an understanding of specific problematic behaviors, including suicide attempts and self-harm.

MBT Training for Clinicians

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McLean’s Gunderson Personality Disorders Institute offers training and continuing education for health professionals focused on treating borderline personality disorder. Learn more about upcoming courses.

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How Mentalization-Based Treatment Works

The first step in MBT is to help patients stabilize their emotional expression and limit their impulsive behaviors. Developing some initial control in these areas helps patients better sense states of mind within themselves and others.

The highly level of emotional attachment common in the therapeutic relationship allows the patient to internalize and learn from interactions with their therapist. Because it is harder for BPD patients to mentalize within intense relationships, the therapist will gradually increase this aspect of the therapeutic bond only as treatment progresses.

As the therapist and patient work together to process the patient’s experiences, including interactions with the therapist, the patient’s mentalizing capacity usually stabilizes. The patient gradually begins to apply a more nuanced and flexible mindset to understanding self and others within the therapeutic relationship and relationships outside of therapy.

Then, every week, the patient participates in individual and group therapy sessions for the determined length of treatment. Treatment is accompanied by crisis planning and integrated care with a psychiatrist or similar provider. A standard MBT treatment period lasts 12-18 months.

During the treatment process, the therapist and patient each express their understanding of the patient’s experiences and reasons for seeking treatment. The therapist does not take an authoritative or “correct” stance in such exchanges.

Instead, the therapist takes a position of curiosity towards patients and sits figuratively “side by side” with the patient in a shared effort to work out what is going on.

MBT is a proven, effective treatment

MBT therapists ask questions of themselves, such as, “Why is the patient behaving like this?” “What might I have done that explains the patient’s state?” “Why am I feeling as I do now?”

Such questions help the therapist maintain a “mentalizing stance.” The therapist may even share these questions with the patient to demonstrate ways to understand how another person may think and reach more accurate conclusions about another person’s behavior.

Instead of offering skills, insights, or explanations, MBT therapists encourage patients to think through hyperactivated or deactivated emotional states themselves.

The point of these therapeutic interactions is for each person to reflect on the point of view of others alongside their own point of view. This increases the patient’s capacity to mentalize multiple perspectives that may differ.

In MBT, the therapist emphasizes a stance of humility. As part of this process, they carefully monitor and acknowledge any misunderstandings they may have about the patient. They own up to and explore such misunderstandings when they do occur.

When the therapist changes their mind based on the experience and feedback of the patient, they demonstrate the openness and flexibility of mentalization. The patient witnesses and internalizes this process in therapy.

As therapy progresses, the patient continues to build on their ability to mentalize. The individual becomes more curious about their own and others’ internal experiences. They become better at understanding and assessing their own and others’ states of mind.

The therapists applies the same treatment techniques in weekly group therapy sessions. The group therapy component of MBT allows patients to work on mentalizing in the context of several different relationships and many different perspectives.

The therapist encourages patients to reflect on the other group members’ motives and experiences by asking questions such as, “Why do you think they might feel that way?” and, “Why might they have said what they did?”

By thinking about emotional and interpersonal situations in different ways, patients learn to view their lives through a lens that is grounded in reality, flexible, and kind to themselves and others.

In addition to leading individual and group therapy sessions, therapists attend a weekly reflection team meeting, in which they receive support from other therapists on their own mentalization regarding the treatment process.

MBT Is Incredibly Effective

MBT is one of several treatments proven effective in treating patients with BPD.

In a 1999 randomized controlled trial, patients in an outpatient hospital, who received MBT as opposed to standard treatment, experienced greater improvements. The MBT group showed decreased suicidality, reduced hospitalization, and improved social skills 18 months, 36 months, and 8 years after treatment.

A 2009 randomized controlled trial of outpatient MBT recruited and trained therapists in either MBT or structured clinical management (SCM). Then 134 BPD patients were assigned to work with therapists from one of the two groups. When assessed at six months, 12 months, and 18 months, the percentage of patients who attempted suicide, engaged in self-harm, or required hospitalization was significantly lower in the MBT group.

A follow-up study published in 2020 demonstrated that the gains made in treatment persisted for six subsequent years after treatment ended, and that patients treated with MBT had better functional outcomes.

Who Benefits From MBT?

While MBT was originally developed for the treatment of borderline personality disorder, its use has been extended to treat antisocial personality disorder, substance use disorders, eating disorders, and anxiety disorders.

Adaptations of MBT have been proposed for treating narcissistic personality disorder, avoidant personality disorder, depression, psychosis, and other conditions.

Finding Treatment Using MBT

Interest in MBT is growing internationally. McLean Hospital’s MBT Clinic offers insurance-based group and individual MBT sessions.

If you or a loved one needs help managing borderline personality disorder, McLean is here to help. Contact us today at 617.855.3452 to learn more about treatment options.

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1. Bateman AW, Fonagy P. Mentalization-based treatment of BPD. Journal of Personality Disorders. 2004;18(10),36-51.
2. Bateman AW, Fonagy P. Mentalization-based treatment. Psychoanalytic Inquiry. 2013;33(6), 595-613.
3. NEA BPD (2012, December 10). Mentalization-based therapy: Dr. Bateman.