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.

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.

Emergency care teams need to organize their response to crises around shared assessment procedures. This chapter describes how MBT can inform emergency care when a crisis is handled by the multidisciplinary team of mental health practitioners in psychiatric emergency settings. Development of the formulation according to mentalizing principles creates compassionate care in emergency settings. The chapter outlines the key factors that commonly contribute to the development of a crisis, and includes a discussion of the centrality of loss of mentalizing and collapse of agency of the self that are part of any acute crisis. Focusing on all of these aspects of a psychiatric emergency can de-escalate an immediate crisis and pave the way for planning how to prevent a recurrence in the future. Understanding of the triggers that can lead to a crisis and development of a plan for reducing the risk of recurrence are illustrated with clinical examples, and the four steps of MBT-informed emergency care are described.