Inpatient cognitive analytic therapy for emotionally unstable personality disorder: A co‐produced and mixed methods single case experimental design

Abstract Objectives To coproduce an evaluation of the effectiveness cognitive analytic therapy (CAT) for emotionally unstable personality disorder (EUPD) conducted during a psychiatric inpatient admission. Design A four‐phase mixed methods single‐case experimental design (i.e. A‐B‐C‐FU design). The first three phases (A‐B‐C) were conducted on an inpatient ward and the follow‐up phase (1 month) coincided with discharge. Methods The intervention was a protocol‐driven eight‐session CAT. Intervention competency was assessed using the CCAT measure. Recognition and revision of three target problems (TPs) and associated target problem procedures (TPPs) were rated at each session. Five idiographic measures (i.e., anxiety, connecting to others, manic mood, obsessional intensity and people‐pleasing) were rated daily across all phases. Nomothetic outcomes (i.e., PHQ‐9 and GAD‐7) were completed at assessment, termination and follow‐up. A change interview with the patient participant was conducted at discharge and follow‐up. The patient participant provides a commentary on the process and outcome of the therapy. Results CAT was delivered competently. Change in TP and TPPs synchronized with CAT phases. Most change in idiographic outcomes occurred during the follow‐up, with discharge being associated with deterioration. There was a reliable improvement to PHQ‐9 and GAD‐7 scores. Changes were rated by the patient as being personally important, impactful and unlikely without CAT. The patient participant’s account of the therapy noted the importance of the inpatient psychological help, the tools of CAT being useful and the ending being painful. Conclusions Brief CAT can be competently delivered on inpatient wards and appeared an acceptable and effective intervention for this EUPD admission. Research directions are provided.