A Study of the Relationship between Borderline-dysregulated Personality and Treatment-resistant Depression in the Course of the TADS Randomised Controlled Trial

Aim: This research project explored the relationship between borderline personality disorder, difficult to treat depression and treatment outcome. Method: The study used data collected in the course of the Tavistock Adult Depression Study (TADS). The TADS was a randomised controlled trial comparing Long Term Psychodynamic Psychotherapy (LTPP) to Treatment as Usual (TAU) for 129 patients whose depression has not been successfully treated by at least two previous interventions. The author of this project took part in rating all patients with the Shedler-Westen Assessment Profile (SWAP-II) – a 200-item personality measure – at the beginning and end of treatment. Statistical analysis explored the relationship between patients’ borderline personality scores at the beginning and end of treatment, and their progress in treatment in terms of decrease in depression severity, and psychological distress, and increase in general functioning. In addition, changes in borderline personality features were also explored in relation to changes on the three main outcome measures. The author included the rest of the SWAP-II personality scales in the analysis, too, as the SWAP-II generates an overall personality profile. Results: Only a small number of patients reached cut-off scores for borderline personality disorder or features. When the SWAP-II borderline scale was entered in analysis as a continuous variable, no significant link was found between borderline personality scores at the beginning of treatment, and treatment outcome. The way borderline features changed in the course of treatment, however, was significantly related to the outcome measures. This was particularly the case for SWAP-II items indicating insecure attachment and affect dysregulation. In addition, patients in the LTPP group who presented with borderline personality features or disorder at the end of treatment were more likely to still experience severe or very severe depression at the end of therapy.