A Pilot Study of High-Frequency Transcranial Magnetic Stimulation for Bipolar Depression

Repetitive transcranial magnetic stimulation (rTMS) is a standard treatment approach for major depressive disorder. There is growing clinical experience to support the use of high-frequency left-sided rTMS in bipolar depression. This study collected open-label safety and effectiveness data in a sample of patients with bipolar depression. Thirty-one adults (13 male/ 18 female; mean age: 42.2 [14.3] years) with bipolar (I or II) depression verified by criteria were recruited at Sheppard Pratt and Mayo Clinic between August 2017 and February 2020 for rTMS. Standardized treatment protocols employed 6 weeks of 10-Hz rTMS to the left dorsolateral prefrontal cortex at 120% of motor threshold with 3,000 pulses per session in 4-second trains with intertrain intervals of 26 seconds. All patients were treated concurrently with a mood stabilizer. The primary outcome measure was the Montgomery-Asberg Depression Rating Scale (MADRS). Response and remission were defined as MADRS score reductions of ≥50% or score <10, respectively. We examined response, remission, and potential contributing factors with multivariate and logistic regression models. The majority of patients with bipolar depression reached response (n = 27; 87.1%) and remission (n = 23; 74.2%). Older age and concurrent treatment with lithium were associated with higher MADRS scores throughout the treatment course (0.1 ± 0.05, =.05; 4.05 ± 1.27, = .003, respectively). Concurrent treatment with lamotrigine was associated with lower MADRS scores (-3.48 ± 1.26, = .01). Treatment with rTMS was safe and well tolerated. There were no completed suicides, induced manic episodes, or other serious adverse events. Although preliminary, the present findings are encouraging regarding the safety and effectiveness of 10-Hz rTMS for bipolar depression. ClinicalTrials.gov identifier: NCT02640950.