Examining the facets of borderline personality disorder in relation to dimensions of eating disorders

Abstract The diagnostic comorbidity between borderline personality disorder (BPD) and eating disorders (EDs) is a clinically perplexing challenge related to severity, treatment prognosis, and mortality. Previous research examining the mechanisms contributing to the relationship between BPD and EDs has produced varied and inconclusive findings that are constrained by categorical conceptualisations of EDs. The present study investigated how, and to what extent, the nine diagnostic features of BPD relate to six core ED features. Participants were N = 340 women between ages 18 to 68 recruited from the general population. Features of BPD and EDs were quantified using the Borderline Personality Questionnaire and the Multifactorial Assessment of Eating Disorders Scale, respectively. To examine how the two sets of variables related, data were analysed using bivariate and canonical correlation analysis. Results suggested that there was a strong relationship between the two disorders and that the strongest ways in which features of BPD related to features of EDs were through (a) an affective disturbance domain, and (b) a relationship between impulsivity, quasi-psychotic states, and purging. These findings serve to clarify the complex relationship between BPD and EDs and improve the current understanding of this relationship by emphasising the importance of affective disturbances.