Borderline Personality Disorder (BPD) diagnosis with the self-report Personality Diagnostic Questionnaire–4+(PDQ-4+): Confirmation of the 3-factor structure

Abstract

Introduction. The clinical heterogeneity and elevated comorbidity of Borderline Personality Disorder (BPD) have suggested the possible existence of several factors or subtypes of this construct. Studies published to date mainly show that this diagnosis could be represented either as a 1-dimensional model or 3-factor model. However, most of the studies have analyzed the factorial structure of the BPD DSM-IV criteria only using semi-structured interviews. This study has aimed to analyze the factorial structure of BPD DSM-IV criteria used in the self-report PDQ-4+.    Method. A total of 159 psychiatric outpatients with suspicion of BPD diagnosis were evaluated. Confirmatory Factor Analyses (CFA) was performed for BPD criteria in PDQ-4+ and two previously defined structures were examined and compared: a 1-dimensional model and a 3-factor model.  Results. Both models showed good fit indexes. However, the results of the CFA showed better goodness of fit indexes (χ²/gl; CFI; RMSEA; TLI; AIC and GFI) for the 3-factor model.    Conclusions. BPD is a construct that can be used to describe three factors of criteria that represent different features of this disorder. The three factors, which could be called Disturbed Relatedness, Affective Instability and Behavioral Dyscontrol, can also be explained by the combination of different diagnostic criteria. The existence of these factors could indicate the presence of different subgroups of BPD patients with different clinical patterns.