Cognitive analytic therapy (CAT) is a form of psychological therapy initially developed in the United Kingdom by Anthony Ryle. This time-limited therapy was developed in the context of the UK's National Health Service with the aim of providing effective and affordable psychological treatment which could be realistically provided in a resource constrained public health system. It is distinctive due to its intensive use of reformulation, its integration of cognitive and analytic practice and its collaborative nature, involving the patient very actively in their treatment. The CAT practitioner aims to work with the patient to identify procedural sequences; chains of events, thoughts, emotions and motivations that explain how a target problem (for example self-harm) is established and maintained. In addition to the procedural sequence model, a second distinguishing feature of CAT is the use of reciprocal roles (RRs). These identify problems as occurring between people and not within the patient. RRs may be set up in early life and then be replayed in later life; for example someone who as a child felt neglected by parents perceived as abandoning might be vulnerable to feelings of abandonment in later life (or indeed neglect themselves). Sources and origins As the name implies, cognitive analytic therapy (CAT) evolved as an integrative therapy based on ideas from cognitive and analytic therapies. CAT was also influenced in part by George Kelly's constructivism. Kelly had developed personal construct theory and the repertory grid method, and Kelly's approach to therapy "offered a model of nonauthoritarian practice" that psychotherapist Anthony Ryle found appealing. Ryle, a general practitioner and analytically trained psychotherapist, was undertaking research into psychotherapy practice using repertory grids in the 1970s. He found that the themes eventually addressed in analytic work were in fact present in transcripts from the very first sessions. However the slow, exploratory nature of traditional analytic therapy meant that these were not always addressed early and assertively, with the result that therapy, while effective, took a long time to produce results. In a 1979 paper, he proposed a shorter, more active form of therapy which integrated elements from cognitive therapy practice (such as goal setting and Socratic questioning) into analytic practice. This would include explicitly formulating the problems experienced by the patient, and sharing this formulation with the patient to engage them in psychotherapy as a co-operative enterprise. Subsequently CAT has been influenced by ideas from the work of Soviet psychologist Lev Vygotsky