Le trouble de personnalité limite est une affection psychiatrique complexe qui se retrouve chez une part non négligeable des jeunes adultes rencontrés dans les services de psychiatrie. En général, les soignants se trouvent démunis face à ces patients, probablement par manque de connaissance de la psychopathologie à l’œuvre dans les interactions interpersonnelles, y compris avec les intervenants, certainement aussi par la rareté d’offres thérapeutiques, médicamenteuses et psychothérapeutiques. Bien que certaines thérapies aient montré leur efficacité dans la prise en charge de cette pathologie, il en ressort que celles-ci ne permettent pas d’appréhender et traiter ce trouble dans sa globalité de manière holistique. En effet, les thérapies cognitivo-comportementales et la thérapie dialectique comportementale, qui sont les traitements couramment utilisés pour les troubles de personnalité limite, ne ciblent que certains symptômes (anxiété, tristesse de l’humeur, comportements autodestructeurs, etc.). À ce jour, seule la thérapie basée sur la mentalisation, développée en 2004 par Bateman et Fonagy, semble aborder le trouble borderline dans toute sa complexité. Pourtant, contrairement aux autres approches thérapeutiques, la thérapie basée sur la mentalisation reste peu connue en France. L’objectif global de cette approche vise le développement d’un processus thérapeutique ciblant l’esprit du patient pour lui permettre de découvrir sa manière singulière de penser et de ressentir à son sujet et au sujet des autres, et comment ces éléments conditionnent ses interactions interpersonnelles. Ce présent article vise donc à présenter ce modèle basé sur la théorie de l’attachement et le concept de mentalisation, qui renvoie à la capacité de se comprendre soi-même et, de comprendre les autres, en déduisant les états mentaux qui sous-tendent les interactions interpersonnelles. Après les bases théoriques ayant présidé à l’élaboration de cette approche, nous aborderons successivement les étapes d’évaluation, et des interventions à proprement parler dans leur mise en œuvre au niveau de la pratique clinique.

The borderline personality disorder is a complex psychiatric disorder that represents a high number of patients in a psychiatric adult service. Even if some therapies have shown to be effective in the therapeutic care of the borderline personality disorder they only target certain symptoms (e.g. anxiety, sadness, self-mutilation). The aim of this paper is to introduce a therapeutic model little known in France: the mentalization based therapy (MBT) developed in 2004 by Bateman and Fonagy. This therapeutic model apprehends the borderline personality disorder in all its complexity and is based on two main concepts: Bowlby's attachment theory and the concept of mentalization. The MBT is based on the hypothesis that a deficit of mentalization leads to the development of borderline disorder. The capacity of mentalization, also known as reflexive function, is acquired in infancy through interpersonal relationships, in particular those of attachment, and is the ability to understand the mental state (emotions, needs, thoughts, etc.) of oneself and others which underlies explicit behaviour. This reflexive capacity is of a better quality when the person has a secure attachment style. Indeed, borderline patients have, mainly, a deficit of mentalization capacity associated with an insecure attachment style. Thus, the main objective of the Bateman and Fonagy approach is to develop and reinforce the mentalization capacity through a therapeutic relationship as a secure base, a group therapy and the concept of insight.

Classically, MBT is structured over a period of 18 months divided into 3 distinct phases distributed in two therapeutic axes: group and individual therapy. The initial phase aims to engage the patient in the therapy by evaluating attachment style, mentalization's ability, interpersonal functioning; providing psychoeducation about borderline disorder and establishing a therapeutic contract. To evaluate attachment style, the authors strongly recommend the use of the Relationship Scales Questionnaire. During the second phase, which includes individual and group therapy, the aim is to stimulate the capacity of mentalization through different techniques according to the patient's attachment style. These include therapeutic relationship, empathy, affect clarification and elaboration, positive and negative reinforcement. The final phase serves to review the patient's improvement and to prepare him progressively for the end of the therapy which can be experienced as an abandonment.

Effectiveness of MBT in treating borderline disorder has been shown in several studies with short and long term benefits. It can be adapted for other personality disorders and specific populations such as adolescents.

This article introduces the key concepts and aims of mentalization based treatment. The therapy is briefly described in its different phases and the various techniques are discussed. Clinical trials have shown that MBT is effective in treating borderline disorder in adolescent and adult populations. Despite the effectiveness of this therapy, it is difficult to set up and requires substantial resources. Interpersonal therapy based on attachment provides a therapeutic model focused on problematic areas which can offer an alternative therapy and reduce the fields of investigations.