Abstract

Borderline personality disorder, a mood disorder characterized by personality and relationship instabilities, and emotional dysregulation, is on the rise in the general and in clinical populations.¹ Pharmacologic and psychotherapeutic approaches to treatment are generally combined to target this disorder but many patients struggle with drug side effects and sticking to their treatment regimen, resulting in limited efficacy for many. Repetitive transcranial magnetic stimulation has recently been approved for treatment of other disorder symptoms and, in a paper recently published by Calderón-Moctezuma et al, this treatment was tested for the purpose of reducing symptoms in borderline personality disorder. To target these symptoms, low-excitatory frequency stimulation was applied to the dorsomedial prefrontal cortex, an area involved with higher cognitive processing of emotions and relationships. Participants that received stimulation reported significantly lower symptom scores in a number of domains, compared to their own pre-treatment scores and to participants that received placebo treatment. 

Background

Borderline personality disorder is a complex personality disorder that has stumped clinicians for decades. While much is known about the symptoms of the disorder, comorbidity with other disorders is extremely common and thus the definition of borderline has changed many times over the years.⁴ These symptoms can include emotional dysregulation, unstable relationships, high impulsivity, and a tendency to engage in range of behaviors that are harmful to the individual and potentially to their surroundings.¹ It is now known that a number of factors come together to create the borderline experience, including genetic predisposition, environmental factors, and comorbid conditions.² However, the exact mechanisms of the disorder are still too complex and elusive for the symptoms to be easily treated. So far, it is thought that borderline personality disorder may arise from neurobiological deficits,¹¹ hypofunctionality, and altered connectivity in cortical and frontal structures.¹ The current method of treatment is generally a combination of pharmacologic and psychotherapeutic approaches, but many patients still struggle with intense symptoms despite modern treatments.^8,9

Repetitive transcranial magnetic stimulation (rTMS) is a non-invasive therapeutic approach to reduce symptoms of several neuropsychological disorders. In the last 15 years, rTMS has been FDA approved for treatment of major depressive disorder (MDD) and obsessive-compulsive disorder (OCD). Therapy of this kind involves the external placement of an electromagnetic coil over the brain area of interest, in which a changing magnetic field is generated to stimulate a current in the brain region through induction. Although this treatment does not cure patients of their disorders, numerous studies have found impressive reductions in symptom severity after highly localized rTMS sessions.^6,7,10 

The dorsomedial prefrontal cortex is a region of the brain located just beneath the forehead, in the center of the frontal lobe. This area has been found to be involved in social cognition, which involves the theory of mind, pro- and anti-social behaviors, and other uniquely human social behaviors. This area is also part of the frontolimbic network, in which cognitive cortical areas connect with the emotional limbic system⁵.  This network between the two regions has been found to be abnormal in borderline personality disorder¹.

Methods

In this single-blind crossover study, participants either received rTMS treatment or believed that they did. Before the first session, participants were to take a number of tests to establish an emotional and cognitive baseline. These tests included the Borderline Symptoms List (BSL), Clinical Global Impression for BPD (CGI-BPD), Borderline Evaluation of Severity over Time (BEST), Hamilton Depression Rating Scale (HDRS), Barratt’s Impulsivity Scale (BIS), Stop-Signal Task (SST), Iowa Gambling Test (IGT), Wisconsin Card-Sorting Test (WCST), and blood testing. Each of these tests were chosen to evaluate the severity of symptoms experienced by the individuals before any treatment sessions began. Clinical evaluations of the disorder were retested weekly (BSL, CGI-BPD, HDRS, HARS, BIS), while the other neuropsychological tests were tested again at the end of each modality. In both the Active group (N=7) and the Sham group (N=7), participants were to wear blindfolds and earplugs to mitigate external stimulation during the session. Both groups were comparable in terms of gender, age, and education level.

During rTMS treatment, Magventure MagPro R30 equipment and Cool D-B80 coils (Active group) or Cool B-65 A/P coils (Sham group) were used. Motor thresholds were obtained daily from each participant, to calibrate the stimulation to each individual. Coils were placed on the skull above the dorsomedial prefrontal cortex. In the Active group, 5-Hz stimulation was applied to the dorsomedial prefrontal cortex at 100% of the motor threshold. Each session consisted of 2 trains containing 50 pulses, with a 10 second interval between trains. All participants engaged in a total of 15 sessions: once a day, five days a week for three weeks. Statistical analyses were performed with IBM SPSS Statistics version 17 and GraphPad Prism version 7 for Windows. 

Results

After treatment, the active group showed significantly lower scores on several tests of symptom severity. On the CGI-BPD test, overall symptom severity scores as well as those for relationship instability, impulsivity, and paranoia were all significantly lower after treatment for the active group. HDRS depression scores were also significantly lower for this group. Anxiety level, evaluated with the HARS test, was significantly lower for the active group compared to the sham group. On the neuropsychological tests, active group participants were found to have significantly lower scores after treatment in decision-making domains. 

These data have a high level of significance within groups, pre- vs. post- treatment. There were also between-group comparisons that were noteworthy, while statistically insignificant. In other words, the results of this study seem to show a distinct impact on the symptomatology of individuals with BPD after rTMS treatment. Active group participants had lower scores on symptom severity tests after treatment than they did before treatment, and lower scores than their sham group counterparts despite having similar scores beforehand.

This study may have major implications for the future of borderline personality disorder treatment, as well as for a number of other psychological disorders. rTMS treatment has shown impressive efficacy in treating depression symptoms, and here it is found that symptoms of other disorders may also be targeted by a similar, simple treatment. While this treatment is not a cure for such disorders,³ alleviating bothersome symptoms is highly desirable for most patients and this type of approach could be more accessible to many than pharmacological therapy, which often results in side-effects and difficulties sticking to regimen in a large number of patients with mood disorders that lead them to be inherently inconsistent in behavior.

[+] References

[+] Other Work By Emily Dale