New form of magnetic brain stimulation may relieve treatment-resistant depression
A new magnetic brain stimulation intervention reduced severe depression symptoms among 90% of participants in a study published in American Journal of Psychiatry.
"There's never been a therapy for treatment-resistant depression that's broken 55% remission rates in open-label testing," Nolan Williams, MD, assistant professor of psychiatry and behavioral sciences at Stanford University, said in a press release. "Electroconvulsive therapy is thought to be the gold standard, but it has only an average 48% remission rate in treatment-resistant depression. No one expected these kinds of results."
The FDA previously approved a noninvasive brain stimulation technique for treatment-resistant depression, called repetitive transcranial magnetic stimulation (rTMS). The agency also approved intermittent theta-burst stimulation (iTBS), which Williams and colleagues described as a more efficient form of rTMS. The updated version significantly shortened the duration of rTMS treatment sessions from 37 minutes to 3 minutes while producing equivalent antidepressant responses.
Research has suggested that the current iTBS protocol might be improved through several methods, including by:
- treating patients with multiple sessions per day at optimally spaced intervals;
- applying a higher overall pulse dose of stimulation; and
- precision targeting of the left dorsolateral prefrontal cortex (DLPFC) to subgenual anterior cingulate cortex (sgACC) circuit.
Williams and colleagues aimed to determine the tolerability, feasibility and preliminary efficacy of Stanford Accelerated Intelligent Neuromodulation Therapy (SAINT) — “an accelerated, high-dose resting-state functional connectivity MRI (fcMRI)-guided iTBS protocol for treatment-resistant depression,” according to the researchers. They administered open-label SAINT to 22 participants with treatment-resistant depression. Using fcMRI, they individually targeted in each participant the region of the left DLPFC most anticorrelated with sgACC. They delivered 50 iTBS sessions, which consisted of 1,800 pulses at a 50-minute intersession interval, as 10 daily sessions across five consecutive days at 90% resting motor threshold, adjusted for cortical depth. Both before and after SAINT administration, they conducted neuropsychological testing.
After one participant withdrew, final data were available for 21 participants. Of these, 19 (90.5%) met remission criteria, which was defined as a score less than 11 on the Montgomery-Åsberg Depression Rating Scale. Nineteen (86.4%) of 22 participants in the intent-to-treat analysis met remission criteria. Participants experienced no negative cognitive adverse effects, according to neuropsychological testing results.
“The potential efficacy of SAINT in treating suicidal ideation and the short duration of the protocol suggest that SAINT could provide a means of rapidly ensuring the safety of suicidal patients,” the researchers wrote. “However, larger, double-blinded, sham-controlled trials are required to confirm the results from this initial study. We remain cautious in our enthusiasm about the present results, as this is an open-label study with all the shortcomings associated with uncontrolled studies.” – by Joe Gramigna
Disclosures: Williams reports patents on the methodology discussed in this study, as well as serving on a scientific advisory board for Halo Neuroscience. Please see the study for all other authors’ relevant financial disclosures.