Reduction of rejection-related emotions by transcranial direct current stimulation over right ventrolateral prefrontal cortex in borderline personality disorder: A double-blind randomized pilot study

Longitudinal Effects of Transcranial Direct Current Stimulation on Daily Rejection-Related Emotions in Borderline Personality Disorder: An Ecological Momentary Assessment Study Protocol

BACKGROUND

Borderline Personality Disorder (BPD) is a debilitating mental health condition characterized by emotional dysregulation and interpersonal dysfunction, with perceived social rejection exacerbating these issues. Emerging evidence suggests that a single session of transcranial direct current stimulation (tDCS) over the right ventrolateral prefrontal cortex (rVLPFC) may decrease the unique tendency of BPD patients to feel rejected even when socially included during a laboratory task.

OBJECTIVES

This protocol outlines a double-blind, sham-controlled study evaluating the longitudinal effects of repeated anodal tDCS over the right ventrolateral prefrontal cortex (rVLPFC) on rejection-related emotions (RRE) during real-life social interactions in individuals with BPD.

METHODS

Sixty BPD patients will be randomized to receive real or sham tDCS across 10 daily sessions, coupled with an ecological momentary assessment (EMA) protocol capturing emotional and behavioral responses to real-life social interactions over four timepoints: baseline, during treatment, ten days post-treatment, and three months post-treatment. Primary outcomes include changes in RRE, with exploratory analyses examining feelings of social connection, aggressive tendencies, trust toward others, and interpersonal and affective dynamics. Multilevel modeling will assess temporal and group-level effects. Expected Results and Impact: This study aims to establish the efficacy of tDCS in reducing BPD patients' negative emotional response in real-life social situations and to determine whether such effects are maintained in time. The findings could advance the clinical application of tDCS as an adjunctive intervention to alleviate social-emotional impairments in BPD, addressing gaps in current treatment approaches and guiding future research into the neural mechanisms of social emotion regulation.

Understanding borderline personality disorder: Clinical features, neurobiological insights, and therapeutic strategies

Borderline personality disorder (BPD) is a complex personality disorder characterised by immense emotional dysregulation, impulsivity, aggression and substantial interpersonal difficulties. This review begins with examining DSM-5-TR diagnostic clusters for BPD, highlighting the importance of accurate classification. It provides an in-depth analysis of BPD, starting with its epidemiology, diagnostic subtypes, core symptoms, and the challenges these symptoms pose for patients and their support networks. The review explores common co-occurring conditions, such as mood disorders, anxiety disorders, and other personality disorders, which frequently compound the effects of BPD and complicate its management. A detailed examination of BPD's neurobiological underpinnings is presented, focusing on structural and functional alterations in brain, aberrant connectivity, and neurotransmitter dysregulation, particularly within serotonin, dopamine, and glutamate pathways, being vital to understanding the effects of this disorder on impulsivity and emotional instability. Therapeutic strategies for BPD are also reviewed, encompassing psychotherapeutic methods like Dialectical Behavior Therapy (DBT) and other validated therapies, alongside pharmacological treatments that target mood stabilisation, impulsivity, and affective control through antidepressants, antipsychotics, and mood stabilisers. Neuromodulation techniques, such as neurofeedback and transcranial magnetic stimulation (TMS), are discussed for their potential to enhance cognitive and emotional control in BPD. The review closes with future directions, emphasizing the value of integrated, personalised treatment approaches to optimise outcomes for individuals with BPD and reduce the broader social and emotional impact of the disorder.