Author: Batya Swift Yasgur, MA, LSW
Date: July 31, 2019
“Deep” repetitive transcranial magnetic stimulation (rTMS) plus standard antidepressant medication is significantly more effective at reducing depression levels in patients with major depressive disorder (MDD) than standard rTMS or stand-alone pharmacotherapy, new research suggests.
In a randomized study, almost 230 participants with treatment-resistant depression (TRD) received either rTMS using an H1-coil (deep rTMS) plus pharmacotherapy, rTMS using a figure-8-coil (standard rTMS) plus pharmacotherapy, or self-standing pharmacotherapy.
Both rTMS protocols, in conjunction with pharmacotherapy, were superior to treatment with pharmacotherapy alone. In addition, secondary analysis showed significantly greater efficacy of rTMS delivered with the H1-coil vs the figure-8-coil.
Both rTMS modalities were comparably safe. No patients dropped out of the study because of adverse events.
“Although the standard H1-coil protocol uses a smaller number of pulses and has a shorter duration of session, it seems to induce a clinical effect that is at least of the same magnitude, and is in fact likely to be greater” than the figure-8-coil, lead author Igor Filipčić, MD, PhD, Psychiatric Hospital “Sveti Ivan” and the School of Medicine, University of Zagreb, Croatia, told Medscape Medical News.
“Our findings suggest an additive and clinically meaningful effect of concurrent rTMS and pharmacotherapy, greater than either treatment alone,” added Filipčić, who is also on the Faculty of Dental Medicine and Health, Josip Juraj Strossmayer University of Osijek, Croatia.
The findings were published in the July issue of the Journal of Psychiatric Research.
It is estimated that 20% to 40% of patients with MDD do not benefit adequately from available interventions, including pharmacotherapy and psychotherapy, the authors write.
rTMS is a noninvasive treatment method that “modulates brain electrical activity by electromagnetic induction.” High-frequency rTMS (HF-rTMS) is applied at 10–20 Hz to the left dorsolateral prefrontal cortex.
In previous studies, figure-8-coil HF-rTMS showed efficacy vs sham treatment in improving symptoms of depression in patients with TRD.
A novel form of “deep TMS” (dTMS) using an H1-coil protocol has been approved by the US Food and Drug Administration (FDA) for treating MDD in adults whose condition does not respond to antidepressant medications in the current episode.
The H1-coil methodology delivers dTMS that targets the PFC bilaterally with preference for the left hemisphere, “where at any depth the model field is higher in the left relative to the right hemisphere,” the investigators write.
“rTMS delivered with the H1-coil…allows noninvasive stimulation of brain regions to a depth that has been estimated to reach approximately 4 cm,” Filipčić said.
There are few data on the safety and efficacy of dTMS. One large randomized trial has been conducted in medication-free adults. No head-to-head trial has compared the two different modalities.
To address this “knowledge gap,” the researchers evaluated and compared the efficacy and safety of the two protocols. They compared both interventions as augmentive in the acute treatment of MDD, and they compared both to self-standing pharmacotherapy.