Objective: Current treatment for borderline personality disorder (BPD) involves psychological and pharmacological interventions. However, neuromodulation techniques such as repetitive transcranial magnetic stimulation (rTMS) may positively affect BPD symptomatology. The objective of this study was to evaluate the clinical and neuropsychological effects of rTMS on the dorsomedial prefrontal cortex (DMPFC) in BPD patients. Methods: Fourteen patients with BPD were randomized into two groups (active vs. sham) for 15 sessions of rTMS on the DMPFC. Clinical effects were measured using the Borderline Symptoms List (BSL), Clinical Global Impression Scale for BPD (CGI-BPD), Borderline Evaluation of Severity over Time (BEST), Hamilton Depression Rating Scale (HDRS), Hamilton Anxiety Rating Scale (HARS), and Barratt’s Impulsiveness Scale (BIS). Neuropsychological effects were determined by a Stop-Signal Task (SST), the Wisconsin Card-Sorting Test (WCST), and the Iowa Gambling Test (IGT). Results: Within-group comparison showed significant differences (p < 0.05) in CGI-BPD (total score and six of nine psychopathologic domains), BEST, HDRS, HARS, and IGT scores for active modality. Conclusion: The 5 Hz-DMPFC rTMS technique was well tolerated and lessened the severity of BPD symptomatology, especially abandonment, affective issues, interpersonal relationships, suicidal behavior, anger, and paranoid ideation. Cognitive improvement was seen in decision-making. Additional studies are needed to fully evaluate the effects of rTMS on BPD symptomatology. Clinical Trial Registration: NCT03832777.

Objective: Current treatment of borderline personality disorder (BPD) consists of psychotherapy and pharmacological interventions. However, the use of repetitive transcranial magnetic stimulation (rTMS) could be beneficial to improve some BPD symptoms. The objective of this study was to evaluate clinical improvement in patients with BPD after application of rTMS over the right or left dorsolateral prefrontal cortex (DLPFC). Method: Twenty-nine patients with BPD from the National Institute of Psychiatry, Mexico, were randomized in two groups to receive 15 sessions of rTMS applied over the right (1 Hz, n=15) or left (5 Hz, n=14) DLPFC. Improvement was measured by the Clinical Global Impression Scale for BPD (CGI-BPD), Borderline Evaluation of Severity Over Time (BEST), Beck Depression Inventory (BDI), Hamilton Anxiety Rating Scale (HAM-A), and Barratt Impulsiveness Scale (BIS). Results: Intragroup comparison showed significant (p < 0.05) reductions in every psychopathologic domain of the CGI-BPD and in the total scores of all scales in both groups. Conclusions: Both protocols produced global improvement in severity and symptoms of BPD, particularly in impulsiveness, affective instability, and anger. Further studies are warranted to explore the therapeutic effect of rTMS in BPD. Clinical trial registration: NCT02273674.