Dorsomedial prefrontal rTMS for depression in borderline personality disorder: A pilot randomized crossover trial

What impact can brain stimulation interventions have on borderline personality disorder?

INTRODUCTION

Borderline personality disorder (BPD) is a severe mental disorder characterized by emotion dysregulation, impulsivity, neuropsychological impairment, and interpersonal instability, presenting with multiple psychiatric comorbidities, functional disability and reduced life expectancy due suicidal behaviors.

AREAS COVERED

In this perspective, the authors explore the application of noninvasive brain stimulation (NIBS) (rTMS, tDCS, and MST) in BPD individuals by considering a symptom-based approach, focusing on general BPD psychopathology, impulsivity and neuropsychological impairments, suicidality and depressive/anxious symptoms, and emotion dysregulation.

EXPERT OPINION

According to a symptoms-based approach, NIBS interventions (particularly rTMS and tDCS) are promising treatment options for BPD individuals improving core symptoms such as emotional and behavioral dysregulation, neuropsychological impairments and depressive symptoms. However, the heterogeneity of stimulation protocols and of assessment tools used to detect these changes limits the possibility to provide definitive recommendations according to a symptom-based approach. To implement such armamentarium in clinical practice, future NIIBS studies should further consider a lifespan perspective due to clinical variability over time, the role of psychiatric comorbidities affecting BPD individuals and the need to combine NIBS with specialized psychotherapeutic approaches for BPD patients and with functional neuroimaging studies.

Pre-clinical indications of brain stimulation treatments for non-affective psychiatric disorders, a status update

Over the past two decades noninvasive brain stimulation (NIBS) techniques have emerged as powerful therapeutic options for a range of psychiatric and neurological disorders. NIBS are hypothesized to rebalance pathological brain networks thus reducing symptoms and improving functioning. This development has been fueled by controlled studies with increasing size and rigor aiming to characterize how treatments induce clinically effective change. Clinical trials of NIBS for specific indications have resulted in federal approval for unipolar depression, bipolar depression, smoking cessation, and obsessive-compulsive disorder in the United States, and several other indications worldwide. As a rapidly emerging field, there are numerous pre-clinical indications currently in development using a variety of electrical and magnetic, non-convulsive, and convulsive approaches. This review discusses the state-of-the-science surrounding promising avenues of NIBS currently in pre-approval stages for non-affective psychiatric disorders. We consider emerging therapies for psychosis, anxiety disorders, obsessive-compulsive disorder, and borderline personality disorder, utilizing transcranial magnetic stimulation (TMS), transcranial direct current stimulation (tDCS), and magnetic seizure therapy (MST), with an additional brief section for early-stage techniques including transcranial focused ultrasound stimulation (tFUS) and transcranial alternating current stimulation (tACS). As revealed in this review, there is considerable promise across all four psychiatric indications with different NIBS approaches. Positive findings are notable for the treatment of psychosis using tDCS, MST, and rTMS. While rTMS is already FDA approved for the treatment of obsessive-compulsive disorder, methodologies such as tDCS also demonstrate potential in this condition. Emerging techniques show promise for treating non-affective disorders likely leading to future regulatory approvals.

Predicting Dimensional Antidepressant Response to Repetitive Transcranial Magnetic Stimulation using Pretreatment Resting-state Functional Connectivity

Repetitive transcranial magnetic stimulation (rTMS) is an effective treatment for depression and has been shown to modulate resting-state functional connectivity (RSFC) of depression-relevant neural circuits. To date, however, few studies have investigated whether individual treatment-related symptom changes are predictable from pretreatment RSFC. We use machine learning to predict dimensional changes in depressive symptoms using pretreatment patterns of RSFC. We hypothesized that changes in dimensional depressive symptoms would be predicted more accurately than scale total scores. Patients with depression (n=26) underwent pretreatment RSFC MRI. Depressive symptoms were assessed with the 17-item Hamilton Depression Rating Scale (HDRS-17). Random forest regression (RFR) models were trained and tested to predict treatment-related symptom changes captured by the HDRS-17, HDRS-6 and three previously identified HDRS subscales: core mood/anhedonia (CMA), somatic disturbances, and insomnia. Changes along the CMA, HDRS-17, and HDRS-6 were predicted significantly above chance, with 9%, 2%, and 2% of out-of-sample outcome variance explained, respectively (all p<0.01). CMA changes were predicted more accurately than the HDRS-17 (p<0.05). Higher baseline global connectivity (GC) of default mode network (DMN) subregions and the somatomotor network (SMN) predicted poorer symptom reduction, while higher GC of the right dorsal attention (DAN) frontoparietal control (FPCN), and visual networks (VN) predicted reduced CMA symptoms. HDRS-17 and HDRS-6 changes were predicted with similar GC patterns. These results suggest that RSFC spanning the DMN, SMN, DAN, FPCN, and VN subregions predict dimensional changes with greater accuracy than syndromal changes following rTMS. These findings highlight the need to assess more granular clinical dimensions in therapeutic studies, particularly device neuromodulation studies, and echo earlier studies supporting that dimensional outcomes improve model accuracy.

Improving treatment outcomes for borderline personality disorder: what can we learn from biomarker studies of psychotherapy?

PURPOSE OF REVIEW

Borderline personality disorder (BPD) is a severe and common psychiatric disorder and though evidence-based psychotherapies are effective, rates of treatment nonresponse are as high as 50%. Treatment studies may benefit from interdisciplinary approaches from neuroscience and genetics research that could generate novel insights into treatment mechanisms and tailoring interventions to the individual.

RECENT FINDINGS

We provide a timely update to the small but growing body of literature investigating neurobiological and epigenetic changes and using biomarkers to predict outcomes from evidence-based psychotherapies for BPD. Using a rapid review methodology, we identified eight new studies, updating our earlier 2018 systematic review. Across all studies, neuroimaging ( n  = 18) and genetics studies ( n  = 4) provide data from 735 participants diagnosed with BPD (mean sample size across studies = 33.4, range 2-115).

SUMMARY

We report further evidence for psychotherapy-related alterations of neural activation and connectivity in regions and networks relating to executive control, emotion regulation, and self/interpersonal functioning in BPD. Emerging evidence also shows epigenetic changes following treatment. Future large-scale multisite studies may help to delineate multilevel treatment targets to inform intervention design, selection, and monitoring for the individual patient via integration of knowledge generated through clinical, neuroscience, and genetics research.

Borderline Personality Disorder: Updates in a Postpandemic World

Progress in understanding borderline personality disorder has unfolded in the last decade, landing in a new COVID-19-influenced world. Borderline personality disorder is now firmly established as a valid diagnosis, distinct from its co-occurring mood, anxiety, trauma-related, and behavioral disorders. Further, it is also understood as a reflection of general personality dysfunction, capturing essential features shared among all personality disorders. Neuroimaging research, representing the vast neurobiological advances made in the last decade, illustrates that the disorder shares frontolimbic dysfunction with many psychiatric diagnoses but has a distinct signature of interpersonal and emotional hypersensitivity. This signature is the conceptual basis of the psychotherapies and clinical management approaches proven effective for the disorder. Medications remain adjunctive and are contraindicated by some guidelines internationally. Less invasive brain-based therapeutics show promise. The most significant change in the treatment landscape is a focus on briefer, less intensive formats of generalist management. Shorter variants of therapies, such as dialectical behavior therapy and mentalization-based treatment, are in the process of being shown to be adequately effective. Earlier intervention and greater emphasis on functional improvement are needed to more effectively curb the disabilities and risks of borderline personality disorder for patients and their families. Remote interventions show promise in broadening access to care.