This chapter considers the neuroscience of borderline personality disorder, also known as emotionally unstable personality disorder, focusing on three domains: neuroendocrinological, structural and functional findings. Research in these areas is related to clinical understanding of borderline personality disorder as characterised by (a) emotional dysregulation, (b) impulsivity and (c) social dysfunction. In patients with borderline personality disorder, the hypothalamic–pituitary–adrenal (HPA) axis tends to show showing elevated continuous cortisol output and blunted cortisol following psychosocial challenges. The amygdala and hippocampus differ from healthy controls in terms of both reduced volume and measurable activity, and the dorsolateral prefrontal cortex tends to be less active. The neurobiology of borderline personality disorder can be characterised as a proneness to flooding by cortisol, with the amygdala working to heighten the affective meaning of stressful stimuli, and the prefrontal cortex underperforming in the task of downregulating emotional experience. The chapter also considers genetic findings in relation to borderline personality disorder.

Antisocial personality disorder (ASPD) and violence result from a loss of mentalizing. Mentalization-based treatment for antisocial personality disorder (MBT-ASPD) is delivered primarily as a group intervention. Individuals with ASPD are more likely to learn from those whom they consider to be similar to themselves, so the task of the MBT clinician is to generate constructive group interactions during which learning can take place. Common mentalizing profiles of people with ASPD are outlined and examples of the formulation that can be used are given. The chapter discusses how to engage patients in treatment using the formulation, and it provides examples of how to prevent dropout by creating an atmosphere of equality within the group. A range of clinical problems that are commonly encountered when running groups for people with ASPD are outlined, and suggestions on how to intervene in these scenarios are given.

The principles of mentalization-based treatment (MBT) as they are applied in clinical practice are discussed. Both the clinician and the patient need to learn to manage their anxiety, as any stress can potentially undermine the ability to mentalize. This chapter focuses in particular on how to maintain the appropriate balance between attachment anxiety and mentalizing ability. The need for a consistent focus on the patient’s process of mentalizing is emphasized, and the importance of not taking over the patient’s mentalizing or joining in with their low mentalizing is highlighted.

From a mentalizing perspective, symptoms of depression arise from reactions to threats to attachment relationships—and thus threats to the self—and associated impairments in mentalizing problems. Mentalization-based treatment (MBT) for depression targets mentalizing impairments, dominant attachment styles, and problems with epistemic trust. Depression is not a homogeneous disorder, and mentalizing problems vary depending on whether the depressed mood is mild, moderate, or severe. Mentalizing interventions for the different severities of depression are summarized. A specific adaptation of MBT, namely dynamic interpersonal therapy (DIT), is also discussed.

The development of mentalizing and non-mentalizing is discussed along with the importance of mentalizing as a psychotherapy process in the treatment of mental health problems. A defining feature of mental disorder is the experience of “wild imagination,” and we consider that mentalizing difficulties—that is, the tendency to get caught up in unhelpful ways of imagining what is going on both for ourselves and for other people—are the price we as a species pay for the immense benefits of the human imagination. Mental health problems arise when mentalizing is lost and we use mentalizing processes that are from earlier stages of development. The relationships between mentalizing, use of low mentalizing modes, epistemic trust and distrust, and social processes are summarized.

From a mentalizing perspective, in attachment trauma an individual’s experience of adversity is compounded by the sense that they have to be able to bear that experience alone. An overwhelming experience cannot be calibrated and managed within an attachment relationship. Normally another mind provides the social referencing that enables an individual to frame and reframe a frightening and potentially overwhelming experience. In the absence of this, the person cannot process the experience, and further development of mentalizing is disrupted. This chapter describes MBT-Trauma Focused (MBT-TF) work, and it illustrates the three phases of treatment by presenting clinical examples. Intervention focuses on mentalizing, avoidance, mental and behavioral systems, managing anxiety and dissociation, and trauma memory processing. An MBT intervention for complex PTSD that uses psychoeducation, group intervention, exposure, and looking to the future is outlined, and is illustrated with clinical examples.

This chapter outlines the use of mentalizing as an essential process for unifying teams and creating a caring environment in relation to schools, fostering of children, and caring for babies in adverse circumstances. An individual’s mentalizing is strongly influenced by their social environment. Any intervention that aims to treat a person with mental health problems must take into consideration that person’s social milieu and the context of their treatment. This chapter discusses how to create a mentalizing milieu. In particular it describes the four quadrants of Adaptive Mentalization-Based Integrative Treatment (AMBIT), a relatively new approach that focuses on creating a mentalizing team, and it outlines Creating a Peaceful School Learning Environment (CAPSLE), a program that facilitates the development of a mentalizing environment in order to reduce bullying and aggression and improve learning in schools.

Social mentalizing informs the theory and practice of mentalization-based treatment for adolescents (MBT-A). Adolescence is, among other things, a time for establishing a self-identity and learning about how to interact effectively with a peer group. A focus on balancing mentalizing in peer and family interactions is crucial, with special attention to hypermentalizing and the alien self. Involvement of families and schools in treatment is necessary. MBT-A includes individual, family, and group therapy, and its overall aim is to develop the patient’s independence. Crucial aspects of achieving this goal include building up relational stability and supporting the patient’s sense of agency and autonomy within their relational networks.

Mentalization-based treatment (MBT) for psychosis focuses on the decoupling of bodily and mental experience as well as the stresses of mentalizing during social interaction. In a framework of mentalizing, psychotic phenomena can be represented as severe disturbances to the experience of oneself as a coherent unit. Clinical treatment that aims to increase integration and stability of self-experience is illustrated in this chapter using clinical examples. The first task is to identify treatment objectives and define any obstacles to treatment, working with co-constructed representations of the clinical problem. The second task is to integrate the viewpoints of the patient, the clinical team, and the social care network, and to agree an overall working formulation. This is followed by therapeutic intervention to stabilize self-mentalizing using interventions from the core MBT model.

In MBT for families (MBT-F), psychoeducation leads to learning about mentalizing problems. Techniques that stabilize mentalizing in all family members are discussed. The stabilizing of individual and interactive mentalizing in the family is achieved through exploration of identified problems using the MBT Loop to bring the family members together so as to create a sense of collectively mentalizing the moment, while also holding on to the idea that each family member has a different perspective. The aim is to generate perspectives from all family members, and then to work on a shared perspective. Exercises are used to enhance this process, and these are illustrated using clinical examples.

Mentalizing or “mind-wondering” is central to social interaction, culture, and morality. In our everyday life we are all philosophers of the mind, wondering what is going on in other people’s heads, and tracking our own thoughts and feelings. Several terms have been used to cover this territory of thinking about thoughts—they include, among others, Theory of Mind, intentionality, and mentalizing. This chapter provides a brief historical account of the emergence and development of the term “mentalizing” from research on Theory of Mind, and its application in clinical practice as mentalization-based treatment (MBT), initially in the context of patients with borderline personality disorder (BPD). The chapter also discusses how, in MBT, the focus is on mentalizing as a way of making sense of mental health problems.

MBT for avoidant personality disorder (AvPD) targets hypermentalizing and hypomentalizing modes along with the problems associated with mentalizing problems found in the polarities of self/other mentalizing which become apparent when the patient engages with their social world. Reducing overuse of the self is central to treatment. The experience of shame is activated during social interaction, and therefore avoidance of social situations maintains a sense of personal comfort and safety. The chapter discusses ways to help the patient to overcome this. Clinician counter-responsiveness, which often relates to feelings of helplessness and hopelessness, can also interfere with engagement and treatment, as the patient may avoid interaction in therapy.