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.

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.

There is considerable evidence of mentalizing problems in patients with eating disorders, with non-mentalizing modes, especially in relation to body weight and shape, being dominant. The mentalizing model assumes the existence of developmental vulnerabilities, especially during adolescence, and that the range of different symptoms associated with eating disorders may have the common function of being attempts at social self-regulation. Controlling eating is a way of managing social and emotional developmental milestones that the person perceives as insuperable. Patients with eating disorders become stuck in a low mentalizing experience of themselves and their bodies. Clinical treatment based on this formulation is discussed as it is applied in a combined program of individual and group psychotherapy, together with psychoeducation.