Mentalisation-based therapy (MBT)

What is MBT?

Mentalisation-based therapy was developed by Peter Fonagy and Anthony Bateman. It focuses on strengthening a core psychological capacity called mentalising, which is the ability to understand behaviour, both your own and other people’s, in terms of underlying mental states such as thoughts, feelings, desires and intentions.

Mentalising is something most of us do automatically, but it can break down under stress, in the heat of conflict, or when we are overwhelmed by strong emotions. When mentalising fails, we are more likely to act impulsively, misread other people’s intentions, feel disconnected from our own emotions, or become rigid in how we interpret situations. These difficulties often lie at the heart of relationship problems, emotional instability and self-destructive behaviour.

MBT does not teach specific cognitive techniques or behavioural strategies. Instead, it creates a therapeutic environment in which you can develop and practise the skill of mentalising in real time. Your psychologist adopts a stance of genuine curiosity, modelling mentalising by exploring your experience openly and collaboratively rather than offering interpretations or advice.

The approach is grounded in attachment theory and developmental psychology. It recognises that our capacity to mentalise is shaped by our early relationships, and that it can be strengthened through a safe, consistent therapeutic relationship in which misunderstandings are noticed, explored and repaired.

To put it practically, mentalising is what allows you to pause before reacting and ask yourself, “What is actually going on here, for me and for the other person?” When this capacity is strong, you can hold different perspectives in mind, tolerate uncertainty about what someone else might be thinking, and respond thoughtfully rather than reactively. When it breaks down, you might jump to conclusions about someone’s motives, act on intense feelings without thinking them through, or shut down emotionally to avoid being overwhelmed.

MBT works on the understanding that these breakdowns are not character flaws. They are the result of a mentalising capacity that was not sufficiently supported during development, often because early caregiving relationships were unpredictable, frightening or emotionally unavailable. The good news is that mentalising is a skill that can be developed at any age, given the right conditions, and that is precisely what MBT provides.

When it helps

MBT is used for a wide range of difficulties, including:

• Difficulties with emotion regulation and relationships
• Self-harm and suicidal behaviour
• Relationship difficulties and interpersonal conflict
• Attachment difficulties
• Complex trauma
• Difficulties with anger and impulsivity
• Eating disorders
• Depression that has not responded to other treatments
• Parenting difficulties linked to attachment

MBT is particularly helpful when your difficulties involve intense, rapidly shifting emotions, confusion about what you or others are feeling, or a tendency to react in ways that damage your relationships. It is well suited for people who find that their emotional responses often seem disproportionate to the situation, or who struggle to understand why they keep ending up in painful interpersonal dynamics.

People dealing with anxiety may also benefit from MBT when the anxiety is closely connected to relationships, for example when you constantly worry about what others think of you, fear abandonment, or find yourself unable to tolerate uncertainty in close relationships. Similarly, those experiencing low self-esteem rooted in early relational experiences often find that strengthening their mentalising capacity helps them develop a more stable and compassionate sense of themselves.

What to expect

MBT typically begins with a psychoeducation phase in which your psychologist helps you understand the concept of mentalising and how it relates to your difficulties. You will explore what happens when mentalising breaks down and learn to recognise the signs that this is occurring. This might include noticing when you become very certain about what someone else is thinking, when you lose touch with your own feelings, or when you find yourself acting impulsively.

Your psychologist will introduce you to different dimensions of mentalising, for example the difference between understanding yourself and understanding others, between thinking about feelings and actually feeling them, and between automatic mentalising and the more deliberate kind that requires conscious effort. These distinctions help you build a more nuanced awareness of your own mental processes.

Sessions are conversational and focus on your current emotional experiences and relationships, including your relationship with your psychologist. Rather than following a fixed structure, your psychologist will pay close attention to moments when mentalising falters, gently drawing your attention to what might be happening beneath the surface. For example, if you describe a conflict with a friend and your psychologist notices that you have become very certain about the friend’s motivations, they might gently invite you to consider whether there could be other explanations.

A key feature of MBT is its focus on the therapeutic relationship as a live laboratory for practising mentalising. Your psychologist will be open about their own responses and actively invite you to consider what they might be thinking or feeling, creating opportunities for genuine relational learning. If a misunderstanding arises between you and your psychologist, this is treated not as a problem but as a valuable opportunity to practise noticing, exploring and repairing a relational rupture in real time.

The pace of MBT is deliberately slow and careful. Your psychologist will frequently check in with you about what is happening emotionally in the moment, rather than rushing ahead with interpretations or explanations. This “not-knowing” stance is central to MBT. It models the kind of curious, open engagement with experience that the therapy is trying to build.

MBT is usually offered over a longer timeframe than many structured therapies, typically 12 to 18 months when working with complex emotional difficulties, though shorter courses may be appropriate for less complex presentations. Sessions are weekly and the work is paced to allow meaningful change in deeply ingrained relational patterns.

The evidence for MBT

MBT has a strong evidence base, particularly for people who experience intense emotions and difficulties in relationships (what services have traditionally diagnosed as ‘borderline personality disorder’). The original randomised controlled trial by Bateman and Fonagy demonstrated that MBT significantly reduced self-harm, suicide attempts, inpatient admissions and depressive symptoms, with gains maintained and even continuing to improve during follow-up.

Subsequent research has replicated these findings across multiple settings and countries. A landmark follow-up study showed that the benefits of MBT were sustained eight years after the end of treatment, with participants continuing to show improvements in social functioning, diagnostic status and overall quality of life. This long-term durability of outcomes is particularly notable and distinguishes MBT from some other approaches.

NICE recommends MBT as one of the evidence-based treatments for these difficulties (which its guidance titles ‘borderline personality disorder’), and it is widely offered within NHS complex emotional needs services across the UK. The National Institute for Health Research has funded further evaluation of MBT, reflecting its status as a priority treatment within UK mental health services.

Beyond these difficulties, research has also supported the use of MBT for eating disorders, depression, difficulties with anger and impulsivity, and parenting interventions. MBT-informed approaches have been adapted for adolescents and families, with promising early evidence.

The theoretical foundations of MBT are supported by extensive developmental psychology and neuroscience research demonstrating the importance of mentalising capacity for emotional regulation, social functioning and mental health. Brain imaging studies have shown that mentalising engages specific neural networks, and that these networks can be strengthened through targeted therapeutic intervention.

Research into online delivery of MBT has been encouraging. Studies and clinical reports from both during and after the pandemic indicate that the core elements of MBT, particularly the emphasis on the therapeutic relationship and moment-to-moment emotional exploration, can be delivered effectively through video. The relational and conversational nature of MBT sessions means that the transition to online format is relatively straightforward.

MBT at The Online Psychologists

At The Online Psychologists, MBT is delivered by HCPC-registered clinical and counselling psychologists who have specific training and experience in mentalisation-based approaches. Our psychologists understand the nuances of working with mentalising difficulties and are skilled at creating the safe, curious therapeutic relationship that MBT requires.

Online delivery works well for MBT. The therapy is fundamentally relational and conversational, relying on the quality of the connection between you and your psychologist rather than on physical materials or structured exercises. Video sessions allow for the kind of close emotional attunement that MBT depends on, including the ability to notice shifts in facial expression, tone of voice and emotional state that are central to mentalising work.

Some clients find that being in their own environment helps them feel safer, which can support the openness that MBT requires. Others find it helpful that the slight distance of the screen reduces the intensity of the work to a manageable level, particularly in the early stages when exploring emotions can feel overwhelming.

When you contact us, we begin with a careful matching process. MBT requires a strong therapeutic fit, and we take time to match you with a psychologist who has the right experience and who is likely to be a good relational match for you. We consider the nature of your difficulties, your previous experience of therapy and any preferences you have.

Session frequency is typically weekly, with each session lasting 50 minutes. The duration of therapy depends on the complexity of your difficulties. For more complex emotional and relational difficulties, MBT is usually offered over 12 to 18 months. For less complex difficulties where mentalising capacity is a relevant factor, shorter courses of 16 to 24 sessions may be appropriate. Your psychologist will discuss the likely duration with you during the early sessions.

MBT at TOP may suit you if you find that your emotional reactions often feel intense and difficult to manage, if you frequently misread other people’s intentions or worry excessively about what they think, or if your relationships tend to follow painful, repetitive patterns. It is also well suited for people who have found that more structured, technique-based therapies have not reached the core of their difficulties.

Frequently asked questions

What does mentalising actually mean in practice? Mentalising is the ability to understand behaviour in terms of what is going on underneath, the thoughts, feelings, motivations and intentions that drive how people act. In practice, it means being able to pause and consider why you or someone else is reacting in a particular way, rather than taking behaviour at face value or jumping to conclusions. It is a skill that affects everything from how you handle disagreements to how you understand your own emotional responses.

Is MBT suitable for people who do not have a formal diagnosis? Yes. Mentalising difficulties are relevant to a wide range of presentations. If you struggle with emotional regulation, find relationships confusing or distressing, or tend to react impulsively under stress, MBT may be helpful regardless of whether you have a formal diagnosis. Your psychologist will assess whether MBT is a good fit for your particular difficulties.

Why does MBT take longer than other therapies? MBT typically runs for longer because it works with deeply ingrained relational patterns that have usually been present since childhood. These patterns take time to shift because they are not simply habits that can be replaced. They involve your fundamental way of experiencing yourself and others. The longer timeframe allows the therapeutic relationship to develop the depth needed for meaningful change, and research shows that the benefits of MBT continue to grow even after therapy ends.

Can MBT be combined with other treatments? Yes. MBT can work alongside psychiatric medication, and many people receiving MBT are also prescribed medication for depression, anxiety or emotional instability. Your psychologist will coordinate with other professionals involved in your care. In some cases, elements of other therapeutic approaches may be integrated where this is clinically appropriate, though the mentalising framework remains central throughout.