Core beliefs assessment procedure : the development of a cognitive-behavioural case formulation method

Abstract

This research evaluated the reliability and validity of a procedure for identifying and assessing core beliefs, the Core Beliefs Assessment Procedure (CAP). The CAP comprised a semi-structured interview, set of markers, and rating system. Twenty participants were administered the CAP. Participants were clients receiving psychotherapy from a community-based mental health service. Core and peripheral case formulations were developed for each participant. Ten participants completed a second assessment session, with a different interviewer, one week later. The CAP showed strong interviewer reliability. In addition, high inter-rater reliability regarding the intensity of affect (r =.87) and the commonness (r =.96) and vividness (r =.93) of metaphor was achieved. Findings suggested that 8 of 12 markers, proposed in the study, adequately distinguished between core and peripheral self-knowledge. Interviewer ratings showed that core self-representations had significantly higher levels of affect, metaphor, and redundancy (i.e., process markers) than peripheral self-representations. Participant ratings showed that core self-representations had significantly higher levels of self-worth contingency, temporal stability, cross-situational consistency and problem relevance (i.e., content markers) than peripheral self-representations. Significant differences were not observed between core and peripheral self-representations on participant ratings of developmental primacy. The relevance of core and peripheral case formulations to the participants' problems were rated both from the perspective of participants and the participants' therapists in order to determine the validity of the CAP. Core case formulations were rated as being more relevant to the participants' problems and as having more utility for guiding treatment than peripheral case formulations. Therapists may find case formulations derived from the CAP useful for guiding treatment. Future research should test the hypothesis that a therapist following a core case formulation has greater treatment success than a therapist following a peripheral case formulation.