Mentalization-Based Treatment (MBT)

Mentalization-Based Treatment (MBT) is a psychodynamic approach with roots in attachment theory and cognitive psychology (Bateman & Fonagy, 2004). Mentalization refers to the ability to focus and reflect on mental states – beliefs, intentions, feelings, and thoughts – in oneself and in others. This ability is thought to be compromised among patients with Borderline Personality Disorder (BPD), in that the capacity to mentalize is highly prone to fluctuation and impairment under stress – particularly the stress of disappointing or rejecting interpersonal experiences. Impaired mentalization is thought to contribute to affect dysregulation, misreading of interpersonal cues, and impulsive behaviour. MBT seeks to promote the development and strengthening of the capacity for mentalization, and thus ameliorate these core features of BPD.

Conceptual Model

MBT is situated within a broad conceptualization of psychological development that encompasses infant development research, evolutionary perspectives, genetics and neuroscience, and cognitive psychology (Fonagy, Gergely, Jurist, & Target, 2002). At the heart of this work lies the concept that affect regulation and cognitive processing capacities – particularly concerning emotions and interactions – develop within the context of relatively secure attachment relationships. Although biological factors are thought to influence the development of reflective functioning, most crucial is the availability of a secure attachment figure who can reflect on the child’s mental states.

Securely attached children, who are themselves “mentalized” by their caregivers, are able to establish cognitive capacities that allow for the appreciation of others’ subjective mental states, along with the realization that mental states do not always correspond to what is observed. In other words, the ability to contemplate the complexities of other peoples’ minds develops out of having had one’s own mental states – e.g. affects and intentions – reliably reflected upon. Insecure attachment, childhood maltreatment or trauma (See section on Traumatic Experiences on the Etiology page), and invalidating relational experiences interfere with this development, contributing to the tenuous and unstable achievement of mentalization (Fonagy, Gergely, Jurist, & Target, 2002). Persons with such vulnerabilities, when stressed, tend to revert to less-complex forms of cognitive and affective functioning. Mentalization tends to be particularly inhibited among patients with BPD during activation of the attachment system, leading to the misreading and concrete interpretation of others’ intentions (e.g. the patient “knows” that the therapist feels bored), along with tendencies to relinquish personal agency and identity (Fonagy & Bateman, 2007).

The Treatment

The developers of MBT assert that successful treatment of BPD entails the enhancing and strengthening of the capacity to mentalize (Bateman & Fonagy, 2006). While it is recognized that other therapies contain elements which likely accomplish this goal, MBT is a manualized protocol which places the restoration of mentalizing at the heart of the treatment approach. Interventions are therefore aimed at helping the patient to reflect on mental states. One of the key elements of fostering such reflection in MBT is the therapist taking a stance of not-knowing (Bateman & Fonagy, 2004). The therapist is to avoid presuming what is on the patient’s mind and delivering interpretations regarding how the patient is feeling or thinking. Indeed, such interventions are considered to be countertherapeutic in that they impede upon the true reflection of the patient’s complex mental states and prevent the patient from developing this capacity. The therapist must instead attempt to maintain their own reflection upon the patient’s experience, which includes an awareness that the patient may not be able to tolerate or make use of verbal explanations. It is expected that, provided the ongoing security of the therapeutic relationship, the patient’s capacity for mentalizing will expand as the therapist models a reflective, perspective-taking approach to discussing attachment relationships and emotional experiences. Essentially, MBT promotes the patient discovering him or herself – and others – through the reliable experience of the therapist’s mind considering the patient’s mind (Bateman & Fonagy, 2004).

The treatment has been designed for implementation by non-specialist mental health practitioners, in a combined individual and group format. Like most other therapies for BPD, MBT is a long-term treatment. Indeed, the developers of MBT have argued that brief treatment, by precipitously activating patients’ attachment systems, may increase the risk of iatrogenic effects in BPD patients and interfere with the natural course of the disorder (Fonagy & Bateman, 2007).

Research on MBT

Empirical support for MBT comes from two randomized clinical trial (RCT) studies, one involving a partial hospitalization program (day treatment) and one involving outpatient treatment. Nineteen patients participated in an 18-month partial hospitalization program consisting of individual and group psychotherapy, along with as-needed medication management, and continued with a subsequent 18 month period of outpatient group MBT (Bateman & Fonagy, 1999). These patients were compared with 19 patients receiving standard psychiatric care, which involved biweekly psychiatric review, biweekly visits with a community psychiatric nurse, and as-needed hospital and day treatment admissions. Patients receiving MBT experienced significant improvement in psychiatric symptoms, including depression, and suicidal behaviour. Frequency and duration of hospital admissions were also reduced among patients receiving MBT (Bateman & Fonagy, 1999). Even more impressive are the follow-up findings, obtained eight years post-baseline (five years after the termination of all MBT service). The patients who received MBT sustained most of the gains experienced during treatment, including improvements in impulsivity and suicidality, global and interpersonal functioning, and service use (Bateman & Fonagy, 2008). Patients who received standard care continued to fare poorly and were 10 times more likely to attempt suicide post-discharge.

A larger trial (N = 134) examined community outpatient provision of MBT in weekly individual and group therapy, compared with structured clinical management offered in a similar format. Both treatments were associated with reduced suicidality, self-harm, and hospitalizations, as well as improvements in symptoms and in social functioning (Bateman & Fonagy, 2009). MBT produced superior changes in suicidality, self-harm, and symptoms. These findings provide support for a less-intensive, outpatient application of MBT. Taken together, these studies indicate that mentalization-based treatment is an efficacious treatment for BPD. Some of the particular virtues of MBT include its implementation by non-specialist practitioners, an emphasis on avoiding iatrogenic effects, and its impressive long-term outcomes.