The Personality Disorders Institute/Borderline Personality Disorder Research Foundation Randomized Control Trial for Borderline Personality Disorder: Reliability of Axis I and II Diagnoses

The Personality Disorder Institute/Borderline Personality Disorder Research Foundation randomized control trial (PDI/BPDRF RCT) is a randomized control trial comparing three treatments for borderline personality disorder (BPD). An important issue for any RCT is diagnostic reliability, demonstration of which is necessary to evaluate claims of a treatment’s efficacy for a given population. The present paper examines the interrater reliability of Axis I and II disorders in the context of a high base rate of BPD features for participants referred for inclusion in the RCT. Our results indicate good to excellent levels of interrater reliability for all Axis I and II disorders in this context. Assessors were able to reliably diagnose BPD, exclusionary criteria, and comorbid diagnoses. This data is important for comparing findings and sample composition across different studies using similar sampling strategies, especially as treatments are increasingly being developed and tested for BPD.