ARTICLESThe Effect of Borderline Personality Pathology on Outcome of Cognitive Behavior TherapyLIS, ERIC MD, CM; MYHR, GAIL MD, CM, MScAuthor Information LIS: Psychiatrist, McGill University Health Centre, Montreal, QC, Canada MYHR: Department of Psychiatry, McGill University, and Director, McGill University Health Centre CBT Unit, Montreal, QC, Canada Ongoing research by the McGill University Health Centre CBT unit was partially funded by the Margaret B. McCullock Foundation of the Royal Victoria Hospital. This study was conducted as part of a research elective during a psychiatry residency and therefore received de facto funding from the government of Quebec and McGill University. The authors declare no conflicts of interest. Please send correspondence to: Gail Myhr, MD, CM, MSc, McGill University Health Centre Cognitive Behavioural Therapy Unit, Department of Psychiatry, McGill University Health Centre, 1025 Pine Avenue West, Montreal, QC, Canada H3A 1A1 (e-mail: [email protected]). Journal of Psychiatric Practice: July 2016 - Volume 22 - Issue 4 - p 270-282 doi: 10.1097/PRA.0000000000000167 Buy Metrics Abstract Cognitive behavioral therapy (CBT) is an evidence-based psychotherapeutic approach which has been shown to be an effective intervention for most psychiatric disorders. There are conflicting data in the literature regarding whether a comorbid personality disorder worsens the prognosis of CBT for depression, anxiety, and other complaints. This study examined data collected before and after courses of CBT for patients with significant borderline (n=39, 11.5%) or obsessive-compulsive (n=66, 19.4%) personality pathology or no personality disorder (n=235, 69.1%). A diagnosis of personality pathology was not a significant predictor of outcome in CBT as measured by the reliable change index. However, patients with borderline personality pathology did demonstrate a greater response to CBT than other patients in terms of improvement on several measures of symptoms. Patients with borderline personality pathology appear to enter therapy with greater subjective depression and interpersonal difficulty than other patients but achieve larger gains during therapy. Implications and directions for future research are discussed. Copyright © 2016 Wolters Kluwer Health, Inc. All rights reserved.