The Case Formulation Task in Psychotherapy: Validity, Reliability and Process of Evidence Gathering and Decision Making

Coherent and accurate formulations are the hallmark of brief and time limited therapies as they enable the clinician to make informed choices about how to focus the work but there is very little research on their validity and reliability. The reformulation is central to CAT in providing a structured understanding of the central problems of the patient and their origins. Unlike other formulation methods it is standard practice for the therapist to share a written formulation with the patient. While it has much practice based evidence to justify and validate its use, relatively little formal research has been conducted on the reliability and validity of reformulations or the process evidence gathering and decision making in writing them.


This research aims to see whether Cognitive Analytic Therapy (CAT) formulations are valid and reliable, that is, whether CAT therapists are able to produce broadly similar written reformulations when presented with the same material and whether the material that is selected is accurate and relevant to the patient. It also aims to examine the rules therapists use to generate reformulations.


The key questions are: Are reformulations in CAT replicable or idiosyncratic? Can the formulations be validated by research tools? What evidence do CAT therapists seek in order to construct reformulations? Does the implicational knowledge of experienced therapists reveal common rules in their evidence seeking?


I asked four experienced CAT therapists to tape the pre-reformulation sessions of a therapy from their routine waiting lists and to write reformulations. They then listened to each others’ tapes and wrote reformulations from these. I then interviewed them individually to explore with them their understanding of the reformulation process in relation to these therapies and to see whether there are common themes in the evidence they seek and the implicit knowledge they use. In a second study I coded the therapies and reformulations using the Structural Analysis of Social Behaviour (Benjamin, L.S. 2003). I compared the generated codes with the reformulations to gain a measure of the validity of the reformulation and the codes between reformulation for the same patient to measure reliability. A matching exercise using independent judges was also used to test reliability.

Estimated completion date: November 2008

Contact details: Lawrence Welch, Psychological Therapies Service, Lea House, Whackhouse Lane, Gateway Drive, Yeadon, Leeds LS19 7XY Email:

November 2014 Update:
Research completed but not yet published


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More information:

Support for CAT research Informal Research Advice Current Research and Research Awaiting Publication Deconstruction of CAT Using a CAT approach to make sense of psychosis Team based Interventions with 5 session CAT consultancy The case formulation task in psychotherapy Therapists’ Construction and Application of the Reformulation Diagram in Clinical Practice RCT of CAT with adolescent and borderline patients Understanding SDRs in CAT CAT Sequential Diagrammatic Reformulation (SDR) to explore service users' experience of CAT formulation: a qualitative thesis project Comparison of Treatment of Anorexia in Adults with CAT Case Series Research - in intellectual disability (community and forensic) services Recently Published Research and Research Presentations A Feasibility Trial of Group Cognitive Analytic Music Therapy in Secure Hospital Settings (2014) Assessment of identity disturbance: Factor Structure and validation of the Personality Structure Questionnaire (PSQ) in an Italian sample CAT and Psychosis Cognitive Analytic Therapy for high-risk sexual behaviour Is Cognitive Analytic Therapy (CAT) effective in treating Hoarding Disorder? Testing the Effectiveness of Cognitive Analytic Therapy for Hypersexuality Disorder: An Intensive Time-Series Evaluation Group Cognitive Analytic Therapy for Female Survivors of Childhood Sexual Abuse An eight-eyed version of Hawkins and Shohet’s clinical supervision model: the addition of the cognitive analytic therapy concept of the ‘observing eye/I’ as the ‘observing us’ Outcomes of cognitive analytic therapy delivered by trainees Treatment of Paranoid Personality Disorder with Cognitive Analytic Therapy - A Mixed Methods Single Case Experimental Design Team Consultancy Using Cognitive Analytic Therapy: A Controlled Study In Assertive Outreach Using a cognitive analytic approach to formulate a complex sexual and violent offender to inform multi-agency working: developing a shared understanding Bipolar Trial: CATBiD: A phase one randomised controlled study of Cognitive Analytic Therapy for Bipolar Affective Disorder Development and evaluation of cognitive analytic guided self-help (CAT-SH) for use in IAPT services How change is enabled during cognitive analytic therapy: An exploratory study of the treatment of depression Key References to Research in CAT Summaries and Meta-analyses of CAT Research Cognitive Analytic Therapy at 30 Cognitive Analytic Therapy: A review of the outcome evidence base for treatment Systematic review and meta-analysis Research and Communication Committee ACAT Research Strategy Donate to ACAT Research Fund Researchers Currently Recruiting Through ACAT CAT Research Archives Do people with learning disabilities have a concept of reciprocal roles Exploring endings from therapist's experience RCT for CAT and diabetes A process study evaluating rupture repair in CAT CAT in groups The SPeDi Trial (Sheffield Personality Disorders) Goodbye Letters in CAT The effectiveness of CAT for BPD RCT for CAT informed care planning CAT and CBT for affective disorders

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