Rectangular Repetitive Transcranial Magnetic Monophasic vs Biphasic Stimulation for Major Depressive Disorder: A...

Biphasic sinusoidal repetitive transcranial magnetic stimulation (rTMS) is a noninvasive brain stimulation treatment that has been approved by the US Food and Drug Administration for treatment-resistant depression (TRD). Recent advances suggest that standard rTMS may be improved by altering the pulse shape; however, there is a paucity of research investigating pulse shape, owing primarily to the technologic limitations of currently available devices. This pilot study examined the feasibility, tolerability, and preliminary efficacy of biphasic and monophasic rectangular rTMS for TRD.

Twenty adult participants with TRD received randomized biphasic and monophasic rectangular rTMS; 30 rectangular rTMS sessions (3000 pulses per session) were delivered as daily sessions over six weeks at 120% resting motor threshold. Neuropsychologic testing was conducted before and after the six-week treatment course, and at one, four, and 12 weeks after treatment.

Two participants withdrew, leaving a final sample size of 18. Both monophasic and biphasic rTMS protocols significantly reduced depressive symptoms in patients with TRD without any significant side effects. In contrast to our hypothesis, there were no differences between the two treatment groups in terms of change in depressive scores, response rates, or remission rates.

Findings from this pilot study revealed that both biphasic and monophasic rectangular rTMS are safe and well-tolerated. Larger, double-blind sham-controlled trials are needed to confirm the response and remission rates observed in this study.

The Clinicaltrials.gov registration number for the study is NCT02667041.