Repetitive Transcranial Magnetic Stimulation Versus Theta Burst Stimulation on Impulsivity, Emotional Dysregulation, and Non-Suicidal Self-Injury in Borderline Personality Disorder Patients (TMS and TBS)

Borderline Personality Disorder (BPD) is a complex psychiatric condition characterized by emotional dysregulation, impulsivity, and recurrent non-suicidal self-injury (NSSI).

Although psychotherapy and pharmacological interventions remain the mainstay of treatment, many patients continue to experience severe emotional instability and impulsivity. Neuromodulation techniques such as repetitive transcranial magnetic stimulation (rTMS) and theta burst stimulation (TBS) have recently shown promise in modulating fronto-limbic circuits involved in emotion regulation.

This prospective, randomized, double-blind, controlled clinical trial aims to evaluate and compare the therapeutic efficacy of high-frequency rTMS and intermittent theta-burst stimulation (iTBS) applied over the left dorsolateral prefrontal cortex (DLPFC) in patients diagnosed with BPD. The interventions are expected to enhance prefrontal modulation of limbic activity, thereby improving emotional regulation, reducing impulsivity, and decreasing non-suicidal self-injury behaviors.

Participants will be randomly assigned to one of three groups:

Group 1: High-frequency rTMS (5 Hz, 1200 pulses/session, 80-110% RMT, 21 min total) Group 2: Intermittent theta-burst stimulation (iTBS, 50 Hz bursts, 600 pulses/session, 80-120% RMT, 21 min total) Group 3: Sham stimulation (matched duration and sound without magnetic output) All participants will continue their standard therapy for BPD, including weekly Dialectical Behavior Therapy (DBT) sessions during the study. Each participant will receive 20 sessions over 4 weeks (5 sessions per week). Allocation concealment will be ensured using sealed, numbered envelopes prepared by an independent administrator, and both participants and assessors will be blinded to group assignment.

Clinical assessments will include:

Structured Clinical Interview for DSM-IV Axis II Disorders (SCID-II) for BPD diagnosis General Health Questionnaire (GHQ-28) to screen for psychiatric comorbidities Difficulties in Emotion Regulation Scale - Short Form (DERS-16) Barratt Impulsiveness Scale (BIS) Deliberate Self-Harm Inventory (DSHI) Measurements will be taken at baseline (pre-intervention) and after completion of the stimulation sessions (post-intervention).

Safety procedures will follow international TMS safety guidelines (Rossi et al., 2009; Lefaucheur et al., 2020). Adverse effects such as transient headache or scalp discomfort will be monitored, and any serious adverse events (e.g., seizures) will be immediately reported to the Research Ethics Committee.

This study seeks to determine whether rTMS or iTBS is more effective than sham stimulation in improving emotion regulation, reducing impulsivity, and decreasing self-harm behaviors. It will also explore whether iTBS, with its shorter session duration, provides a comparable or superior therapeutic benefit to conventional rTMS.