Right DLPFC repetitive transcranial magnetic stimulation in women with borderline personality disorder: A double-blind randomized sham-controlled trial

Background: Borderline personality disorder (BPD) is characterized by emotional dysregulation and high rates of suicidal and self-harming behavior, while effective treatments remain limited. This study evaluated short- and long-term effects of right dorsolateral prefrontal cortex (DLPFC) rTMS in a double-blind, sham-controlled design, accounting for concurrent treatment and trauma history.

Methods: Thirty women with BPD and recent nonsuicidal self-injury or suicidal behavior underwent 15 sessions of active or sham 10-Hz rTMS targeting the right DLPFC over three weeks. Outcomes were assessed at baseline, post-treatment, and three- and six-month follow-up. Primary analyses compared longitudinal trajectories between groups using linear mixed-effects models.

Results: No significant Group × Time interactions were observed for primary outcomes, indicating no evidence of differential longitudinal change between active and sham stimulation. Exploratory within-group analyses showed reduced self-reported depressive symptoms in the active group at post-treatment (β = -0.58), with borderline-significant reductions at three and six months; medication adjustment yielded a significant effect at three months (β = -0.78), but not six months (β = -0.62). Impulsivity decreased in the sham group at three (β = -0.58) and six months (β = -0.59). Self-harming and suicidal behavior decreased in both groups at three and six months. Dissociation decreased in the sham group at three months (β = -0.53).

Conclusion: No evidence of superior longitudinal effects of active versus sham rTMS was observed. Exploratory within-group findings warrant further investigation but do not establish stimulation-specific efficacy. Larger sham-controlled trials are needed to determine the efficacy and durability of rTMS in BPD.