| Paper authors: | Daniel M. Blumberger, Fidel Vila-Rodriguez, Wei Wang, Yuliya Knyahnytska, Michael Butterfield, Yoshihiro Noda, Shahak Yariv, Moshe Isserles, Daphne Voineskos, Nicholas J. Ainsworth, Sidney H. Kennedy, Raymond W. Lam, Zafiris J. Daskalakis, Jonathan Downar |
| Year of paper publication: | 2021 |
| Post authors: | Caleb Pozdnikoff, Lisa Ridgway, Fidel Vila-Rodriguez |
| Download the research article: | Blumberger et al. (2021) A randomized sham controlled comparison of once vs twice-daily intermittent theta burst stimulation in depression: A Canadian rTMS treatment and biomarker network in depression (CARTBIND) study |
Introduction
In the NINET Lab’s previous studies involving repetitive transcranial magnetic stimulation (rTMS) for treatment-resistant depression (TRD), the rTMS “treatment course” lasts 4-6 weeks, with one treatment each day. Could the treatment be done in fewer weeks if people got treated more than once a day?
This is the question that the current study examines. Instead of one treatment per day, this study compares the effectiveness of two treatments per day. For each treatment, researchers used a type of rTMS called intermittent theta burst stimulation (iTBS). The researchers used iTBS in this study to decrease the duration of each appointment as it is only 3 minutes long, as compared to traditional rTMS treatment which is around 37.5 minutes long.
The researchers conducted this study in the hopes of shortening the treatment course for people who don’t live close to a centre that offers rTMS. In this way, people may see results faster and would not have to travel as often to appointments. The researchers also wanted to assess if this faster treatment course reduced depression symptoms further than the usual treatment course while remaining as tolerable.
Methods
Researchers recruited 208 patients with treatment-resistant depression. All of these individuals had to have not responded to at least one prior antidepressant treatment. Participants were randomly assigned to one of two groups. Each group received a different number of pulses. The twice-daily group received 2 treatments consisting of 600 TMS “pulses” (stimulations) then 600 placebo pulses each treatment. The once-daily group received one treatment of 1200 placebo pulses and one treatment of 1200 TMS pulses. This way, each person spent the same amount of time with the rTMS equipment and staff. This also ensured that both the patient and research staff were “blinded” and did not know which treatment was given to who, preventing bias in the study.
Each patient received 30 days of treatment. The researchers administered questionnaires to the patients to assess depression severity throughout the trial. The results of these questionnaires were compared between the twice-daily group and the once-daily group.
Results
- Twice-daily iTBS did not lead to significantly greater or faster improvement in depression symptoms compared to once-daily iTBS at either 10 or 30 days.
- There were no significant differences in response or remission rates between the twice-daily and once-daily treatment groups.
- Both once-daily and twice-daily iTBS protocols were found to be safe, well-tolerated, and demonstrated clinically meaningful reductions in depressive symptoms.
Conclusion
Despite expectations, this study found that for people with treatment-resistant depression, twice-daily iTBS did not significantly accelerate depression symptom reduction. This means that people receive the benefits of rTMS at the same rate, even with twice-daily iTBS. It also means twice-daily iTBS did not significantly improve depressive symptoms compared to once-daily iTBS. Both treatment protocols, however, demonstrated clinically meaningful reductions in depressive symptoms and were found to be safe and well-tolerated. These findings suggest that doubling iTBS sessions does not proportionally increase recovery speed or overall outcomes, so more research has to be done.