Dialectical behaviour therapy v. mentalisation-based therapy for borderline personality disorder

Barnicot, K., & Crawford, M. (2019). Dialectical behaviour therapy v. mentalisation-based therapy for borderline personality disorder. Psychological Medicine, 49(12), 2060–2068. https://doi.org/10.1017/S0033291718002878

Summary by: Hadija Satel

Introduction: Borderline Personality Disorder (BPD) is a mental health condition that involves emotional instability, self-harm, problems in relationships, and frequent use of emergency or hospital services. Two therapies that are commonly used to treat BPD are Dialectical Behaviour Therapy (DBT) and Mentalisation-Based Therapy (MBT). While both treatments have strong evidence supporting their effectiveness, there has never been a direct comparison between the two. The 2019 study by Barnicot and Crawford, published in Psychological Medicine aimed to examine how DBT and MBT compare in terms of clinical outcomes over a 12-month period.DBT is a therapy that focuses on teaching practical skills to manage emotions, reduce self-harm, and improve relationships. It combines cognitive-behavioural methods with mindfulness. MBT, focuses on helping patients understand their own and others' mental states more clearly. This process is called mentalizing. While DBT is usually delivered over 12 months, MBT often lasts around 18 months, but for the purpose of this study, both treatments were evaluated over the same 12-month period.

Method: The study included 90 adults diagnosed with BPD. 58 participants received DBT and 32 participants received MBT in six specialist NHS personality disorder services in London and Southampton. The allocation of participants was not randomized. The choice of therapy was based on what was available in each local service. This approach demonstrated real-life practice but also meant there were some differences in the patient groups. At the beginning of the study,the researchers saw that people in the DBT group tended to have more severe symptoms. They were more likely to have self-harmed recently, had more frequent hospital visits, and higher rates of post-traumatic stress disorder (PTSD). They also showed higher levels of emotional dysregulation. These differences were important and were taken into account in the statistical analysis. Throughout the 12-month period, participants were assessed every three months. The study measured how many people dropped out of therapy, how often they used crisis services, how often they self-harmed, and their levels of BPD symptoms, emotional dysregulation, dissociation, and interpersonal difficulties.

Results: The results showed that both DBT and MBT helped reduce symptoms of BPD. At the end of the 12 months, there were no significant differences between the two groups in terms of self-harm rates, emotional dysregulation, BPD severity, or relationship difficulties. This means that both treatments appeared to be similarly effective by the end of the year. However, when looking at how quickly patients improved over time, there were important differences. People receiving DBT had a steeper reduction in self-harm incidents and faster improvements in emotional dysregulation than those receiving MBT. These findings remained significant even after adjusting for differences in baseline severity, dropout rates, and other confounding factors. This suggests that while both therapies work, DBT may help patients improve more quickly in reducing self-harming behavior and improving emotional control.The study also found differences in treatment dropout. A larger percentage of MBT patients (72%) completed the full 12 months of therapy compared to DBT patients (42%). However, once the researchers adjusted for initial differences between the groups, this difference in completion rates was no longer statistically significant. The higher dropout rate in DBT may be partly explained by the fact that patients starting DBT had more severe symptoms and may have had more difficulty staying engaged. Interestingly, while DBT patients initially seemed to use crisis services more often, these differences disappeared once the analysis controlled for the more severe starting point of the DBT group. In other words, DBT patients may not have used crisis services more because of the therapy itself, but because they were already more at risk before starting treatment.

Discussion: The study has several strengths. It was conducted in real-world clinical settings with actual NHS services, making the results relevant to everyday practice. It also included people who dropped out of treatment, which gives a more complete picture of how the therapies perform in practice. The researchers adjusted for initial differences between the two groups. However, there were some limitations. Since patients were not randomly assigned to DBT or MBT, it’s possible that unknown factors influenced the results. Also, the study only followed patients for 12 months, while BPD is a long-term condition that may require longer follow-up to fully understand treatment effects. Another limitation was that the researchers did not assess how closely the therapists followed the official DBT or MBT manuals, which could affect how effective the treatments were.

In conclusion, this study found that both DBT and MBT are helpful for people with BPD. however there were differences such as DBT appeared to produce faster improvements in reducing self-harm and emotional dysregulation. MBT, on the other hand, may have better retention rates. These results show  that both treatments have their strengths, and choosing between them might depend on the individual needs of the patient, such as their level of risk or ability to stay engaged in long-term therapy. This study also shows the importance of offering a variety of evidence-based treatments within mental health services, so that patients with BPD can receive care that best fits their circumstances. While more research, especially randomised trials is still needed, this comparison gives useful guidance for clinicians and services when deciding which therapy to offer.