Construct Validity of the McLean Screening Instrument for Borderline Personality Disorder in Two Singaporean Samples

This study examined the construct validity of the McLean Screening Instrument for Borderline Personality Disorder (MSI-BPD) in a consecutive sample of adult psychiatric patients (n = 128) and a separate sample of undergraduate students (n = 289) in Singapore. Participants were administered the MSI-BPD and other measures assessing related symptoms of BPD. Patients were also administered a semistructured interview by interviewers blind to their MSI-BPD scores. Confirmatory factor analyses revealed a unique three-factor solution, consisting of affect dysregulation, self-disturbances, and behavioral and interpersonal dysregulation. In both samples, the MSI-BPD demonstrated good internal consistency and convergent validity. The measure also showed good discriminant validity and predictive accuracy (AUC = .82), with an optimal cut-off score of 7.5. Overall, the findings suggest that BPD is a valid and coherent clinical construct in Singapore, and point to the need to further clarify the presentation and etiology of BPD in this cultural context.