Significant interpersonal impairment is a cardinal feature of borderline personality disorder (BPD). However, past research has demonstrated that the interpersonal profile associated with BPD varies across samples, evidence for considerable interpersonal heterogeneity. The current study used Inventory of Interpersonal Problems – Circumplex (IIP-C; Alden, Wiggins, & Pincus, 1990) scale scores to investigate interpersonal inhibitions and excesses in a large sample (N = 255) selected for significant borderline pathology. Results indicated that BPD symptom counts were unrelated to the primary dimensions of the IIP-C, but were related to generalized interpersonal distress. A latent class analysis clarified this finding by revealing six homogeneous interpersonal classes with prototypical profiles associated with Intrusive, Vindictive, Avoidant, Nonassertive, and moderate and severe Exploitable interpersonal problems. These classes differed in clinically relevant features (e.g., antisocial behaviors, self-injury, past suicide attempts). Findings are discussed in terms of the incremental clinical utility of the interpersonal circumplex model and the implications for developmental and nosological models of BPD.

Theory and research point to the role of attachment difficulties in borderline personality disorder (BPD). Attachment insecurity is believed to lead to chronic problems in social relationships, due, in part, to impairments in social cognition, which comprise maladaptive mental representations of self, others, and self in relation to others. However, few studies have attempted to identify social cognitive mechanisms that link attachment insecurity to BPD and to assess whether such mechanisms are specific to the disorder. For the present study, empirically derived indices of mentalization, self-other boundaries, and identity diffusion were tested as mediators between attachment style and personality disorder symptoms. In a cross-sectional structural equation model, mentalization and self-other boundaries mediated the relationship between attachment anxiety and BPD. Mentalization partially mediated the relationship between attachment anxiety and antisocial personality disorder (PD) symptoms, and self-other boundaries mediated the relationship between attachment anxiety and avoidant PD symptoms. The findings support theories that insecure attachment is associated with difficulties in social cognition and that a distinctive pattern of impairment characterizes BPD.

Emotional dysregulation and impaired attachment are seen by many clinical researchers as central aspects of borderline personality disorder (BPD). Alternatively, these constructs may represent general impairments in personality that are nonspecific to BPD. Using multitrait-multimethod models, we examined the strength of associations among preoccupied attachment, difficulties with emotion regulation, BPD features, and features of two other personality disorders (i.e., antisocial and avoidant) in a combined psychiatric outpatient and community sample of adults. Results suggested that preoccupied attachment and difficulties with emotion regulation shared strong positive associations with each other and with each of the selected personality disorders. However, preoccupied attachment and emotional dysregulation were more strongly related to BPD features than to features of other personality disorders. Our findings suggest that although impairments in relational and emotional domains may underlie personality pathology in general, preoccupied attachment and emotional dysregulation also have specificity for understanding core difficulties in those with BPD.

The proposal for the diagnosis of personality disorders (PDs) in the Diagnostic and Statistical Manual of Mental Disorders, 5th edition (DSM-5; American Psychiatric Association, in preparation) involves, in part, the use of elevated scores on dimensional personality traits. For instance, the diagnosis of borderline personality disorder (BPD) in the DSM-5 will require evidence of self- and interpersonal impairment as well as elevated scores on traits of emotional lability, anxiousness, separation insecurity, depressivity, impulsivity, risk taking, and hostility. Using a sample of individuals from the community (N =134), half of whom were receiving psychiatric treatment, we tested whether the summation of relevant personality trait scores, using data derived from a measure of the Five-Factor Model of personality (FFM), would result in a construct that corresponds to the Diagnostic and Statistical Manual of Mental Disorders, 4th ed. (DSM–IV, American Psychiatric Association, 2000) BPD construct as scored by expert consensus ratings. The DSM–IV and FFM BPD scores were significantly correlated (r =.60) and generated highly similar patterns of relations (ricc =.84) with key constructs from BPD’s nomological network. These data should serve to allay concerns that the DSM-5’s new diagnostic approach will be detrimental to the identification of BPD.

We examined within-individual changes in emotion dysregulation over the course of one year as a maintenance factor of borderline personality disorder (BPD) features. We evaluated the extent to which (1) BPD symptom severity at baseline predicted within-individual changes in emotion dysregulation and (2) within-individual changes in emotion dysregulation predicted four BPD features at 12-month follow-up: affective instability, identity disturbances, negative relationships, and impulsivity. The specificity of emotion dysregulation as a maintaining mechanism of BPD features was examined by controlling for a competing intervening variable, interpersonal conflict. BPD symptoms at baseline predicted overall level and increasing emotion dysregulation. Additionally, increasing emotion dysregulation predicted all four BPD features at 12-month follow-up after controlling for BPD symptoms at baseline. Further, overall level of emotion dysregulation mediated the association between BPD symptom severity at baseline and both affective instability and identity disturbance at 12-month follow-up, consistent with the notion of emotion dysregulation as a maintenance factor. Future research on the malleability of emotion dysregulation in laboratory paradigms and its effects on short-term changes in BPD features is needed to inform interventions.