Factors associated with co-occurring borderline personality disorder among inner-city substance users: the roles of childhood maltreatment, negative affect intensity/reactivity, and emotion dysregulation.

The co-occurrence of borderline personality disorder (BPD) among individuals with substance use disorders is a common and clinically relevant phenomenon in need of further empirical investigation. The present study adds to the extant literature on the factors associated with co-occurring BPD among substance users, examining the relationships between childhood maltreatment (in the form of sexual, physical, and emotional abuse and emotional and physical neglect), negative affect intensity/reactivity, emotion dysregulation, and BPD pathology (both diagnostic status and symptom count) among a sample of 76 inner-city treatment-seeking substance users. Emotion dysregulation was expected to mediate the relationships between childhood maltreatment and negative affect intensity/reactivity (and their interaction) and BPD pathology. Results indicate that the presence of a BPD diagnosis was associated with higher levels of both childhood maltreatment and negative affect intensity/reactivity. However, only childhood maltreatment emerged as a unique predictor of BPD diagnostic status. Conversely, both childhood maltreatment and negative affect intensity/reactivity accounted for unique variance in the number of endorsed BPD symptoms. Moreover, emotion dysregulation fully mediated the relationships between maltreatment and negative affect intensity/reactivity and BPD symptom count, as well as the relationship between emotional abuse in particular and BPD diagnostic status. Contrary to hypotheses, results provided no support for the interaction between maltreatment and negative affect intensity/reactivity in the prediction of BPD pathology (diagnosis or symptom count), above and beyond the main effects of these factors.