Borderline personality pathology and the stability of interpersonal problems.

Features of borderline personality disorder (BPD) are associated with the presence and severity of interpersonal problems. At the same time, individuals with BPD are heterogeneous with regard to the types of interpersonal problems they display. BPD is also associated with temporal instability in various domains (e.g., affective lability), and this characteristic raises questions about whether BPD is associated with changes in the expression of interpersonal dysfunction over time, which may contribute to the observed heterogeneity. The focus of the present study was to evaluate the relationship between BPD features and the stability of interpersonal problems over the course of 1 year. Participants (N = 150) were assessed for borderline personality pathology at baseline and also completed the Inventory of Interpersonal Problems-Circumplex Scales at baseline and every 3 months over the course of a year. Baseline BPD was used to predict structured (i.e., latent growth trajectories) and unstructured (i.e., mean square of successive differences) change parameters in generalized interpersonal distress, agentic problems, and communal problems across assessment waves. Baseline BPD predicted individual means in generalized distress and unstructured change (i.e., instability) in agentic and communal problems across the year. Baseline BPD was not predictive, however, of structured change (i.e., linear change trajectories) for any aspect of interpersonal problems. These findings support the conclusion that interpersonal dysfunction in borderline pathology is stable in its severity but unstable in the style of its manifestation.