Cognitive Analytic Therapy for Borderline Personality Disorder: Therapist Competence and Therapeutic Effectiveness in Routine Practice


Correspondence to: Stephen Kellett, Clinical Psychology Unit, The University of Sheffield, Western Bank, Sheffield S10 2TN, UK.



This study sought to examine the competency of cognitive analytic therapy (CAT) delivered under routine care conditions and to identify the effectiveness of CAT for patients with borderline personality disorder (BPD). Ten cognitive analytic therapists in six National Health Service Trust sites treated 19 patients with BPD using the standard CAT BPD contract of 24 sessions plus four follow-ups. The methodology was small N repeated measures deign, with patients interviewed at the third follow-up session using the Change Interview. Results indicate a high treatment and follow-up compliance rate (89.47%). Significant reductions in psychological distress, risk and dissociation over the time course of the CAT occurred, with a significant increase in personality integration. Most sessions (92.85%) were delivered in a competent manner. Reductions to psychological distress occurred early in treatment and were sustained, whereas increases in personality integration typically occurred later on in treatment. Patients tended to attribute change to the therapy received. Benchmarking against extant CAT BPD evidence notes a moderate effect size across routine care and trial contexts. The results are discussed in terms of identified methodological shortcomings, clinical implications and the contribution made by the CAT model to the treatment of BPD. Copyright © 2011 John Wiley & Sons, Ltd.

Key Practitioner Message

  • Narrative and diagrammatic reformulation in CAT offers the opportunity for early and effective engagement and potential symptomatic change in patients with BPD.
  • It is possible to measure outcomes on a session-by-session manner with patients with BPD.
  • Assessing fidelity to the treatment model is useful in practice-based studies.