This chapter explores the use of cognitive and behavioural therapies (CBT) in the treatment of mental disorders. It describes the origins and evolution of CBTs and their relationship to other key therapies. The focus of cognitive theory on intrapsychic processes that mediate actions and reactions has parallels with psychoanalytic theory. There are several variants of cognitive therapy, but the shared features of CBT are that these are action-orientated, pragmatic, manualised approaches that can be used to understand and treat mental disorders. CBT focused on personality disorders is heavily orientated towards schema change and inevitably focuses on interpersonal issues, including interactions between the therapist and patient. The chapter gives examples of some of the key areas in which cognitive models have been developed, and describes the cognitive model of depression and anxiety disorders. It also provides comments on future directions for research and practice in this field.