Effectiveness of Predominantly Group Schema Therapy and Combined Individual and Group Schema Therapy for Borderline Personality Disorder

Arntz, A., Jacob, G. A., Lee, C. W., Brand-de Wilde, O. M., Fassbinder, E., Harper, R. P., Lavender, A., Lockwood, G., Malogiannis, I. A., Ruths, F. A., Schweiger, U., Shaw, I. A., Zarbock, G., & Farrell, J. M. (2022). Effectiveness of predominantly group schema therapy and combined individual and group schema therapy for borderline personality disorder: A randomized clinical trial. JAMA Psychiatry, 79(4), 287–299. https://doi.org/10.1001/jamapsychiatry.2022.0010

Summary by: Zeynep Ersoy

A person with Borderline Personality Disorder (BPD) often experiences difficulties with emotion regulation, impulsivity, and interpersonal relationships. Therefore, schema therapy has emerged as a promising treatment. Yet, despite growing evidence, an important clinical question remains: What is the most effective way to deliver schema therapy to individuals with BPD? The randomized clinical trial conducted by Arntz et al. (2022) offers a decisive answer. In this study, three different treatments were compared: predominantly group schema therapy (PGST), combined individual and group schema therapy (IGST), and treatment as usual (TAU). The treatment-as-usual condition most frequently consisted of dialectical behavior therapy, but other psychological treatments were also used. Another feature that makes this study important is that it was conducted at 15 different locations across five countries, involving 495 participants: Germany, the Netherlands, Greece, Australia, and the UK. This multinational design strengthens the generalizability of the findings. The study examined whether BPD severity decreased and investigated the longer-term effects of the interventions.

First, the most significant finding was the difference in effectiveness between the treatment methods. IGST stood out compared to the other treatment groups. It produced a large effect size compared to TAU (Cohen's d = 1.14) and significantly outperformed PGST (d = 0.84), whereas PGST did not differ significantly from TAU. This suggests that patients with BPD may benefit particularly from IGST and that several factors could contribute to this. Schema therapy is beneficial for BPD treatment because it works with early maladaptive schemas and attachment needs. One possible explanation for the difference between IGST and PGST is the greater emphasis on individual therapy in IGST, which allows therapists to work more deeply with childhood trauma, attachment injuries, and shame-related schema modes. These topics can be too sensitive or overwhelming to address in a group setting. On the other hand, group sessions can reflect the real-world relational difficulties that characterize BPD by providing opportunities to explore interpersonal patterns and receive feedback from peers. As a result, the combination of group and individual schema therapy appears to be a promising treatment method for BPD.

In addition to the effectiveness of these treatments, another important point is treatment retention. Treatment dropout can be a major barrier to successful BPD treatment, but the IGST condition demonstrated the highest retention rates over the two-year treatment period. Higher retention may increase the likelihood of sustained therapeutic gains. In addition, improvements in BPD severity continued during the follow-up period, suggesting that the benefits of treatment may extend beyond the therapy itself. This could indicate that patients were able to apply what they had learned even after treatment ended. Another important finding was that IGST was more effective than TAU in reducing suicidality and suicide attempts, which further highlights the clinical importance of this treatment.

Finally, there are also limitations to this study. Group schema therapy was generally delivered by therapists with limited experience in this specific group format. Also, some individual schema therapists were using this method for the first time. Therefore, in future research, it could be important to control for therapists' experience and investigate how training and supervision influence treatment outcomes. Another limitation is that treatment as usual was not standardized across the different locations, making direct comparisons more difficult. Although several psychological treatments were used as treatment as usual, IGST showed greater improvements than TAU. Testing these approaches in a multinational sample and examining not only short-term but also longer-term effects are important strengths of the study.

Ultimately, this study has significant clinical implications. Professionals seeking to use schema therapy in the treatment of BPD may benefit from combining group dynamics with individual therapy. Integrating both approaches can offer longer-term benefits. Focusing on emotional depth while also taking advantage of interpersonal interactions and feedback can produce encouraging results for people with BPD.

In conclusion, Arntz et al. (2022) provide evidence that combined individual and group schema therapy is a highly effective and clinically meaningful way to deliver schema therapy for borderline personality disorder. IGST emerges as a promising model for addressing both the intrapersonal and interpersonal dimensions of BPD. Its strong results, high retention rates, and sustained improvements make it an important treatment option and suggest that it may be the preferred format of schema therapy for treating BPD.