Dysfunctional cognitions in personality pathology: the structure and validity of the Personality Belief Questionnaire.

BACKGROUND: This study examines the structure of the Personality Belief Questionnaire (PBQ), a self-report instrument designed to assess dysfunctional beliefs associated with personality pathology, as proposed by the cognitive theory of personality dysfunction.
METHOD: The PBQ was examined using exploratory factor analysis (EFA) with responses from 438 depressed out-patients, and confirmatory factor analysis (CFA) with responses from 683 treatment-seeking psychiatric out-patients. All participants were assessed for personality disorder (PD) using a standard clinical interview. The validity of the resulting factor structure was assessed in the combined sample (n=1121) by examining PBQ scores for patients with and without PD diagnoses.
RESULTS: Exploratory and confirmatory analyses converged to indicate that the PBQ is best described by seven empirically identified factors: six assess dysfunctional beliefs associated with forms of personality pathology recognized in DSM-IV. Validity analyses revealed that those diagnosed with a PD evidenced a higher average score on all factors, relative to those without these disorders. Subsets of patients diagnosed with specific DSM-IV PDs scored higher, on average, on the factor associated with their respective diagnosis, relative to all other factors.
CONCLUSIONS: The pattern of results has implications for the conceptualization of personality pathology. To our knowledge, no formal diagnostic or assessment system has yet systematically incorporated the role of dysfunctional beliefs into its description of personality pathology. The identification of dysfunctional beliefs may not only aid in case conceptualization but also may provide unique targets for psychological treatment. Recommendations for future personality pathology assessment systems are provided.