Bilateral Repetitive Transcranial Magnetic Stimulation Decreases Suicidal Ideation in Depression

Objective: The purpose of this study was to evaluate the effects of repetitive transcranial magnetic stimulation (rTMS) on suicidal ideation in patients with treatment-resistant major depression (TRD) (patients who failed to clinically respond to at least 2 medication trials). Methods: We pooled data from 2 published prospective randomized controlled trials of rTMS applied to the dorsolateral prefrontal cortex in patients with TRD. We compared the effect of bilateral, left unilateral, and sham rTMS on suicidal ideation as measured by the suicide item of the 17-item Hamilton Depression Rating Scale (HDRS) (N=156). Results: Suicidal ideation resolved in 40.4%, 26.8%, and 18.8% of participants randomized to bilateral, left unilateral, and sham rTMS, respectively. The difference between bilateral and sham was significant (OR = 3.03; 95% CI, 1.19-7.71; P =.02), unlike the difference between left unilateral and sham (OR = 159; 95% CI, 0.61-4.12; P =.33). There was a modest correlation between change in suicidal ideation and change in depression severity (Pearson r=0.38; P< .001) and no difference in change of HDRS-16 score between suicide remitters and nonremitters (P = 32). Conclusions: Bilateral rTMS was superior to sham rTMS in reducing suicidal ideation in patients with TRD. Only a small portion of the reduction in suicidal ideation was attributable to the reduction in depressive symptoms. These data suggest that suicidal ideation could be a specific target symptom construct for rTMS.