Despite recent advancements in the treatment of Borderline Personality Disorder (BPD), little is known about the underlying mechanisms in the development and maintenance of the disorder. To examine these issues, it is first necessary to identify a brief screening measure that can be used to assess factors underlying BPD. Considering this need, the current investigation examined the utility of a BPD-related composite consisting of the Inventory of Interpersonal Problems-Interpersonal Sensitivity (IIP-IS) and Aggression (IIP-Ag) subscales of the IIP in a sample of college students ( [Formula: see text] ) and a sample of individuals seeking residential drug use treatment ( [Formula: see text] ). Data indicated that score on this composite measure (IIP-BPD) was positively related to scores on measures tapping BPD-related symptomotology, as well or better than the IIP total score in all cases. These data suggest the specificity of the IIP-BPD and support its use in analogue studies to better understand the mechanisms underlying the disorder.