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.

Background: Intermittent theta burst stimulation (iTBS) is a newer form of repetitive transcranial magnetic stimulation (rTMS) for patients with treatment resistant depression (TRD). Applying multiple daily iTBS sessions may enable patients to achieve remission more rapidly.

Objective: We compared the efficacy and tolerability of a twice-daily versus once-daily iTBS protocol in patients with TRD. We hypothesized that twice-daily iTBS would result in a greater improvement in depression scores compared to once-daily iTBS.

Methods: 208 participants (131 females) with TRD were randomized to receive either iTBS (600 pulses) delivered twice-daily with a 54-min interval between treatments or once-daily (1200 pulses) with 1 sham treatment with the same interval between treatments, to ensure equal levels of daily therapeutic contact and blinding of patients and raters. The primary outcome measure was change in depression scores on the Hamilton Rating Scale for Depression (HRSD-17) after 10 days of treatment and 30 days of treatments.

Results: HRSD-17 scores improved in both the twice-daily and once-daily iTBS groups; however, these improvements did not significantly differ between the two groups at either the 10-day or 30-day timepoints. Response and remission rates were low (<10%) in both groups after 10 days and consistent with prior reports at 30 days; these rates did not differ between the treatment groups.

Conclusions: These results suggest that twice-daily iTBS does not accelerate response to iTBS and is not different from once-daily treatment in terms of improving depressive symptoms in patients with TRD. Clinicaltrials.gov ID: NCT02729792 (https://clinicaltrials.gov/ct2/show/NCT02729792).