Pervasiveness in conflictual relationship patterns and defensive functioning: unpacking their role in borderline personality disorder

This dissertation unfolds through three studies, with the first two stemming from a randomized controlled trial (RCT) (NCT03717818) conducted at Lausanne University Hospital and the University of Lausanne (project SNSF100014_179457/1) funded by the Swiss National Science Foundation and granted to Prof. Dr. Ueli Kramer as principal investigator from October 2018 to January 2024. The trial was concerned with the mechanisms of change in 10-session General Psychiatric Management (GPM), a brief psychodynamically-oriented psychiatric treatment for Borderline Personality Disorder (BPD). The first article explores how the pervesiveness of core conflictual relationship themes (CCRT) and overall defensive functioning (ODF) interact to predict changes in symptom severity among two groups: BPD-GPM and BPD-TAU (Treatment-as-Usual). 60 patients with BPD (75% female, mean age 29.6) were interviewed with Relationship Anecdote Paradigm at pretreatment to assess ODF and three defensive categories (mature, neurotic, immature) using the Defense Mechanisms Rating Scales-Q-sort (DMRS-Q), and the CCRTs to calculate the overall CCRT pervasiveness (OCP). Symptom severity changes were measured using the Zanarini Rating Scale for BPD, subtracting intake scores from post-treatment scores. Results showed that lower CCRT pervasiveness predicted a significant decrease in affective disturbance, and more frequent use of mature defenses significantly predicted improvements in disturbed relationships, with these effects being more pronounced in GPM compared to TAU. Instead, TAU led to a worsening of affective disturbance for individuals with lower OCP. No significant results were found regarding the prediction and interaction of ODF with OCP in altering borderline symptom.The findings of the first study highlighted that while some patients benefit significantly from this brief intervention, others experienced mixed outcomes, with some even worsening in certain symptom domains. This prompted me to examine and illustrate the treatment process of a 22-year-old patient with BPD from the same RCT, based on the rationale of the “Cases within Trials” (CWT) Model (Fishman et al., 2017). An in-depth investigation of her treatment process revealed a reduction in the CCRT pervasiveness, both overall and in each component; however, a decline in defensive functioning warranted further examination due to its potential impact on increasing affective and relational symptom severity. My exploration of defense mechanisms sparked a profound interest in its implications for psychopathology and the psychotherapy process, ultimately guiding me to develop the third study of my dissertation. This final study investigated the psychometric properties of the Turkish version of the Defense Mechanisms Rating Scales-Self-Report-30 (DMRS-SR-30) within the general population. It represents a crucial first step toward conducting further research on defensive functioning and its impact on therapeutic outcomes within a different linguistic and cultural context. Overall, this dissertation1 aims to contribute to the development of an empirically grounded comprehensive model of BPD while addressing current shortcomings in the literature regarding predictors and outcome changes following brief treatments. It underscores the importance of moving beyond the divide between science and practice, advocating for the integration of both quantitative and qualitative approaches. By doing so, the dissertation seeks to empower clinicians to utilize evidence-based decision trees when selecting the most appropriate psychological interventions for their patients.