Intermittent theta burst stimulation, a shorter version of the 37-minute repetitive transcranial magnetic stimulation that can be delivered in 3 minutes, was noninferior to the longer version for treatment-resistant depression, findings published in The Lancet revealed.
“Several pilot trials and two meta-analyses indicate that [intermittent theta burst stimulation] is superior to sham treatment for treatment-resistant depression. However, the key practical question is whether [intermittent theta burst stimulation] performs comparably to the existing standard of care,” Daniel M. Blumberger, MD, of the department of psychiatry, University of Toronto, and colleagues wrote. “If 3-minute [intermittent theta burst stimulation] sessions were noninferior to the standard, FDA-approved 37.5-minute 10 Hz sessions, then the capacity, cost, and accessibility of [repetitive transcranial magnetic stimulation] would improve several-fold, greatly improving its clinical usefulness.”
Researchers examined the effectiveness, safety and tolerability of intermittent theta burst stimulation (iTBS) compared with standard 10 Hz repetitive transcranial magnetic stimulation (rTMS) in adults with hard-to-treat depression in a randomized, noninferiority trial.
The study enrolled patients referred to specialty neurostimulation centers in Canada who were diagnosed with treatment-resistant major depression and receiving stable antidepressant medication for at least 1 month prior to baseline. The investigators randomly assigned participants to receive treatment with 10 Hz rTMS or iTBS to the left dorsolateral prefrontal cortex, administered 5 days a week for 4 to 6 weeks, then compared change in depression score between the groups. The noninferiority margin was 2.25 points.
After 4 to 6 weeks of treatment, 192 participants who received 10 Hz rTMS and 193 who received iTBS were examined to determine change in depression score. Analysis showed depression scores improved from 23.5 to 13.4 among patients who received rTMS, while the scores improved from 23.6 to 13.4 among those who received iTBS (lower 95% CI, –1.16; P = .0011), indicating that iTBS was noninferior to rTMS. However, patients reported higher intensity of pain in the iTBS group than in the rTMS group (mean score on verbal analogue scale, 3.8 vs. 3.4 out of 10; P = .011).
Furthermore, the dropout rates did not differ between the groups (13 patients in the rTMS group vs. 16 in the iTBS group; P = .6004). The most commonly reported adverse event related to treatment was headache in both groups (131 patients for rTMS vs. 136 for iTBS).
“A typical iTBS treatment session (including setup) takes about 5 to 10 minutes, compared with about 45 minutes for standard 10 Hz rTMS. The number of patients treated per machine, per day can be tripled or quadrupled by use of iTBS,” the authors wrote. “More broadly, the potential for increased capacity, improved access, reduced waiting times, and potentially reduced costs per remission should have a positive effect, aiding health insurers and governments in implementing wider coverage of rTMS as an increasingly practical intervention for patients with medication-resistant depression.”
These findings show that transcranial magnetic stimulation is promising, but further research of both its clinical- and cost-effectiveness is necessary, Glyn Lewis, PhD, division of psychiatry, University College London, wrote in an accompanying comment.
“Now that we know that iTBS is noninferior to the standard 10 Hz TMS, we should conduct trials to investigate the long-term cost-effectiveness of iTBS vs. sham to provide the robust, convincing and generalizable clinical guidance that we still require,” Lewis wrote. – by Savannah Demko
Disclosures: Blumberger reports grants from Brain Canada, Brainsway, the Canadian Institutes of Health Research, Temerty Family Foundation, U.S. National Institutes of Health and Weston Brain Institute. He also reports receiving in-kind equipment support for investigator-initiated studies (including this study), being the site principal investigator for three sponsor-initiated studies for Brainsway; and being on advisory board for Janssen. Please see the full study for all other authors’ relevant financial disclosures. Lewis is currently acting as an expert witness in a case.