Organization of co-occurring Axis II features in borderline personality disorder.

OBJECTIVES: Considerable heterogeneity exists in the comorbid Axis II features that frequently accompany borderline personality disorder (BPD). These features have potential to be meaningfully organized, relate to specific BPD presentation, and have implications for treatment process and outcome. The present study explored patterns of Axis II comorbidity in order to identify subtypes of BPD.

DESIGN: A well-defined sample of 90 patients diagnosed with BPD was recruited as part of an RCT study. Participants were administered the International Personality Disorder Examination (Loranger, 1999) to diagnose BPD and assess comorbid Axis II features. Other measures were also administered to assess aspects of current work and relationship functioning, symptomatology, and self-concept.

METHODS AND RESULTS: Q-factoring was used to develop subtypes based on commonly occurring Axis II profiles, identifying three: Cluster A (elevated paranoid and schizotypal features), Cluster B (elevated narcissistic and histrionic features), and Cluster C (elevated avoidant and obsessive-compulsive features). An additional factor analysis revealed two dimensions underlying the comorbid features identifiable as: extraversion versus introversion and antagonism versus constraint. Validity of these two maps of comorbidity was explored in terms of the BPD criteria themselves, as well as on work and relationship functioning, identity diffusion, views of self and others, positive and negative affect, behavioural dyscontrol, and symptomatic distress.

CONCLUSIONS: Clinically meaningful subtypes can be identified for BPD based on co-occurring Axis II features. Further research is needed to replicate and further establish base-rates of these subtypes as well as their differential implications for treatment.