Differential Item Functioning for Gender and Age of the DSM-IV Borderline Personality Disorder Criteria in a Large Clinical Sample

This study examined the DSM-IV/DSM-5 Borderline Personality Disorder (BPD) in a clinical sample of 4102 patients (845 diagnosed with BPD) using Item Response Theory analysis, with special emphasis on Differential Item Functioning (DIF) across gender and age. Among the three criteria that displayed DIF for age, Fear of abandonment and Self-injurious behavior were more frequently assigned to female patients as compared with male patients situated at the same position on the latent BPD scale. Uncontrolled anger was more commonly attributed to male patients at equivalent levels of latent BPD severity. For age, DIF was present for five criteria. Self-injurious behavior and Affective instability were more prevalent in the younger age group (18–25), given the same severity levels as the older age group. Conversely, Unstable relationships, Impulsivity, and Dissociation were more frequently identified in older patients. Identity problems showed no DIF and had good discriminative ability. The results were interpreted in light of the view that BPD is a proxy for general personality pathology severity. As such, the behavioral-oriented criteria, notably Self-injurious behavior and Uncontrolled anger, posed the most challenges in terms of DIF, and caution is advised in using these criteria to assess general severity.