Personality Traits in Borderline Personality Disorder: A Cluster Analysis Based on the Millon Test Scores

The complexity of the treatment of borderline personality disorder (BPD) is largely due to its heterogeneity. The aim of this study is to identify empirically derived patterns of co-occurring personality traits in individuals with primary BPD and to examine their clinical correlates.

Millon's personality traits (MCMI-IV) of 97 BPD patients were assessed and a cluster analysis of these traits was performed. Patients were evaluated on different clinical dimensions of BPD and compared between the different clusters found.

Three trait-pattern clusters were obtained. Pattern 1 showed higher scores for borderline, histrionic, narcissistic and antisocial traits. Pattern 2 had higher scores for borderline, dependent and avoidant traits. Pattern 3 had lower levels of all the traits. Patients in patterns 1 and 2 showed greater scores on anxious-depressive scales. Pattern 1 also showed greater scores for anger expression. Pattern 3 patients were characterized for receiving more pharmacological treatment.

Findings provide evidence for three patterns of co-occurring traits within BPD, consistent with dimensional conceptualizations and longstanding categorical overlap. These patterns align with externalizing-leaning, internalizing-leaning, and attenuated configurations and may help generate hypotheses for early characterization and treatment personalization.