The antidepressant effect of intermittent theta burst stimulation (iTBS): study protocol for a randomized double-blind sham-controlled trial

• Published in: Trials
• Main Authors: Marte Christine Ørbo, Ole K. Grønli, Camilla Larsen, Torgil R. Vangberg, Oddgeir Friborg, Zsolt Turi, Matthias Mittner, Gabor Csifcsak, Per M. Aslaksen
• Format: Article in Journal/Newspaper
• Language: English
• Published: BMC 2023
• Subjects: Intermittent theta burst stimulation; Depression; Cognition; Randomized controlled trial; Magnetic resonance imaging; Genetic factors; Medicine (General); R5-920; Norway; Northern Norway
• Online Access: https://doi.org/10.1186/s13063-023-07674-6; https://doaj.org/article/4f38f013a0324ddfbce399f76000014e

Abstract Background Intermittent theta burst stimulation (iTBS) when applied over the left dorsolateral prefrontal cortex (DLPFC) has been shown to be equally effective and safe to treat depression compared to traditional repetitive transcranial magnetic stimulation (rTMS) paradigms. This protocol describes a funded single-centre, double-blind, randomized placebo-controlled, clinical trial to investigate the antidepressive effects of iTBS and factors associated with an antidepressive response. Methods In this trial, outpatients (N = 96, aged 22–65 years) meeting the diagnostic criteria for at least moderate depression (Montgomery and Aasberg Depression Rating Scale score ≥ 20) will be enrolled prospectively and receive ten, once-a-day sessions of either active iTBS or sham iTBS to the left DLPFC, localized via a neuronavigation system. Participants may have any degree of treatment resistance. Prior to stimulation, participants will undergo a thorough safety screening and a brief diagnostic assessment, genetic analysis of brain-derived neurotropic factor, 5-HTTLPR and 5-HT1A, and cerebral MRI assessments. A selection of neuropsychological tests and questionnaires will be administered prior to stimulation and after ten stimulations. An additional follow-up will be conducted 4 weeks after the last stimulation. The first participant was enrolled on June 4, 2022. Study completion will be in December 2027. The project is approved by the Regional Ethical Committee of Medicine and Health Sciences, Northern Norway, project number 228765. The trial will be conducted according to Good Clinical Practice and published safety guidelines on rTMS treatment. Discussion The aims of the present trial are to investigate the antidepressive effect of a 10-session iTBS protocol on moderately depressed outpatients and to explore the factors that can explain the reduction in depressive symptoms after iTBS but also a poorer response to the treatment. In separate, but related work packages, the trial will assess how clinical, cognitive, ...