Mentalization-based treatment (MBT) is a form of psychotherapy designed for individuals with emotionally unstable personality disorder, borderline type (EUPD-BT), also known as borderline personality disorder (BPD).

At its core, MBT aims to improve individuals’ ability to mentalize; a person’s ability to work out what they, as well as others, might be thinking and feeling, and what their intentions might be. The idea is that this should improve one’s ability to manage their emotions, thereby reducing suffering through, e.g. improving their relationships with others, reducing self-harming and suicidal thoughts, feelings and behaviours.

Therapy examines mainly the present moment, attending to events of the past only insofar as they have an impact on the individual in the present. Other core aspects of treatment include a stance of curiosity, partnership with the patient rather than an ‘expert’ type role, monitoring and regulating emotional arousal, and identifying the affect focus.

MBT is offered to patients twice per week with sessions alternating between group therapy and individual treatment. During sessions the therapist works to stimulate or nurture mentalizing. Particular techniques are employed to lower or raise emotional arousal as needed, to interrupt non-mentalizing and to foster flexibility in perspective-taking. Activation of the attachment system occurs through the elaboration of current attachment relationships, the therapist’s encouragement and regulation of the patient’s attachment bond with the therapist and the therapist’s attempts to create attachment bonds between members of the therapy group. The safe attachment relationship with the therapist provides a relational context in which it is safe for the patient to explore the mind of the other. 

Extensive research has been conducted on MBT for borderline personality disorder. The first randomized, controlled trial was published in 1999, concerning MBT delivered in a partial hospital setting. The results showed real-world clinical effectiveness that compared favorably with existing treatments for BPD. A follow-up study published in 2003 demonstrated that MBT is cost-effective. Encouraging results were also found in an 18-month study, in which subjects were randomly assigned to an outpatient MBT treatment condition versus a structured clinical management (SCM) treatment. The lasting efficacy of MBT was demonstrated in an 8-year follow-up of patients from the original trial, comparing MBT versus treatment as usual. In that research, patients who had received MBT had less medication use, fewer hospitalizations and longer periods of employment compared to patients who received standard care. Replication studies have been published by other European investigators. Researchers have also demonstrated the effectiveness of MBT for adolescents as well as that of a group-only format of MBT.