Group schema therapy for cluster-C personality disorders: A multicentre open pilot study.

BACKGROUND: Group schema therapy (GST) is increasingly popular as a treatment for personality disorders (PDs), including Cluster-C PDs. Individual ST has proven to be effective for Cluster-C PD patients, while the evidence for GST is limited. This study aimed to investigate the effectiveness of GST for Cluster-C PD. Moreover, differences between the specific Cluster-C PDs (avoidant PD, dependent PD and obsessive-compulsive PD) were explored. METHODS: A multicentre open trial was conducted, including 137 patients with a Cluster-C PD (avoidant PD: n = 107, dependent PD: n = 11 and obsessive-compulsive PD: n = 19). Patients received 30 weekly GST sessions with a maximum of 180 min of individual ST and five optional monthly booster sessions. Outcome measures including Cluster-C PD severity, general psychopathological symptoms, quality of life, functional impairment, happiness, PD-related beliefs, self-esteem, self-ideal discrepancy, schemas and schema modes were assessed at baseline until 2-year follow-up with semi-structured interviews and self-report measures. Change over time and differences between the specific Cluster-C PDs were analysed with mixed regression analyses. RESULTS: The outcome measures showed significant improvements for all Cluster-C PDs, with medium to large effect sizes after 2 years. A treatment dropout rate of 11.7% was found. There were some indications for differences between the Cluster-C PDs in severity at baseline, change trajectories and effectiveness of GST. CONCLUSIONS: This study demonstrated that GST is a promising treatment for Cluster-C PDs. The following step is a randomized controlled trial to further document the (cost-)effectiveness of GST.

Towards optimal treatment selection for borderline personality disorder patients (BOOTS): a study protocol for a multicenter randomized clinical trial comparing schema therapy and dialectical behavior therapy.

BACKGROUND: Specialized evidence-based treatments have been developed and evaluated for borderline personality disorder (BPD), including Dialectical Behavior Therapy (DBT) and Schema Therapy (ST). Individual differences in treatment response to both ST and DBT have been observed across studies, but the factors driving these differences are largely unknown. Understanding which treatment works best for whom and why remain central issues in psychotherapy research. The aim of the present study is to improve treatment response of DBT and ST for BPD patients by a) identifying patient characteristics that predict (differential) treatment response (i.e., treatment selection) and b) understanding how both treatments lead to change (i.e., mechanisms of change). Moreover, the clinical effectiveness and cost-effectiveness of DBT and ST will be evaluated. METHODS: The BOOTS trial is a multicenter randomized clinical trial conducted in a routine clinical setting in several outpatient clinics in the Netherlands. We aim to recruit 200 participants, to be randomized to DBT or ST. Patients receive a combined program of individual and group sessions for a maximum duration of 25 months. Data are collected at baseline until three-year follow-up. Candidate predictors of (differential) treatment response have been selected based on the literature, a patient representative of the Borderline Foundation of the Netherlands, and semi-structured interviews among 18 expert clinicians. In addition, BPD-treatment-specific (ST: beliefs and schema modes; DBT: emotion regulation and skills use), BPD-treatment-generic (therapeutic environment characterized by genuineness, safety, and equality), and non-specific (attachment and therapeutic alliance) mechanisms of change are assessed. The primary outcome measure is change in BPD manifestations. Secondary outcome measures include functioning, additional self-reported symptoms, and well-being. DISCUSSION: The current study contributes to the optimization of treatments for BPD patients by extending our knowledge on "Which treatment - DBT or ST - works the best for which BPD patient, and why?", which is likely to yield important benefits for both BPD patients (e.g., prevention of overtreatment and potential harm of treatments) and society (e.g., increased economic productivity of patients and efficient use of treatments). TRIAL REGISTRATION: Netherlands Trial Register, NL7699 , registered 25/04/2019 - retrospectively registered.