Beyond boundaries: Rethinking Diagnostics and Improving Treatment for Patients with Posttraumatic Stress Disorder and Comorbid Borderline Personality Disorder

This dissertation seeks to improve treatment outcomes for patients with posttraumatic stress disorder (PTSD) and comorbid personality disorders (PDs), particularly borderline personality disorder (BPD). The co-occurrence of PTSD and PDs poses significant clinical challenges, including diagnostic complexity and high rates of treatment nonresponse and dropout. The study introduces innovative approaches to enhance treatment, tracking the patient's journey from diagnosis to completion. Chapter 1 outlines the historical development of diagnostic and treatment strategies for PTSD and PDs, shedding light on both achievements and persistent challenges over the last century. Chapter 2 presents a meta-analysis exploring how PDs affect trauma-focused treatment outcomes. Surprisingly, patients with and without PDs showed similar PTSD severity and dropout rates initially. Although patients with comorbid PDs experienced notable symptom reduction, their improvement was less pronounced compared to those without PDs. These findings highlight the need for tailored approaches to improve outcomes for patients with PTSD and comorbid PDs. Chapter 3 employs network analysis to investigate the symptom structure of PTSD and BPD. Unlike the DSM-5, which defines disorders by symptom checklists, network analysis conceptualizes them as interconnected systems. Results revealed sparse connections between PTSD and BPD symptoms. Central symptoms such as intrusive memories, physiological cue reactivity and loss of interest might be valuable treatment targets, offering opportunities for more precise and effective interventions. Chapter 4 reports two randomized controlled trials (RCTs) comparing the efficacy of concurrent trauma-focused and PD treatments with standalone trauma-focused therapies. The first RCT examined combined eye movement desensitization and reprocessing (EMDR) with dialectical behavior therapy (DBT) versus EMDR alone in patients with PTSD and BPD. The second RCT compared imagery rescripting (ImRs) combined with group schema therapy (GST) to ImRs alone in patients with PTSD and cluster C PDs. Contrary to expectations, both combined and standalone treatments produced similar improvements in PTSD and PD symptoms. However, EMDR-DBT showed higher dropout rates and smaller gains in global functioning. These findings affirm the effectiveness of trauma-focused therapies for addressing both PTSD and PD symptoms without requiring additional concurrent PD treatment. Chapter 5 delves into the predictors of treatment dropout, an issue identified across trauma-focused and PD treatments. Analysis of data from the RCTs revealed five key predictors: (1) severe PTSD symptoms correlated with higher session attendance, possibly due to greater therapeutic needs; (2) a strong therapeutic alliance improved attendance; (3) lower educational levels were linked to fewer sessions; (4) inadequate social support predicted lower attendance; and (5) patients in combined treatments attended fewer sessions than those in standalone trauma-focused therapies. These insights inform strategies to enhance treatment engagement. Chapter 6 examines the impact of the COVID-19 pandemic on PTSD severity in the study cohort. A positive correlation was observed between pandemic-related distress and PTSD severity, underscoring the vulnerability of these patients during crises and the importance of timely interventions. Chapter 7 synthesizes findings, emphasizing that trauma-focused therapy alone is effective for patients with PTSD and comorbid PDs. Adding PD treatment does not confer additional benefits and may increase dropout rates. Therefore, initiating treatment with trauma-focused therapy is recommended before considering extended PD-specific interventions. The integration of network analysis with the DSM-5 model and addressing dropout predictors can further optimize treatment outcomes. Collectively, these findings aim to refine diagnostic and therapeutic strategies for patients with PTSD and comorbid PDs, promoting more efficient and effective care.