Theta burst stimulation with 80 and 120% resting motor threshold do not differ in their antidepressant efficacy: a retrospective analysis
European Archives of Psychiatry and Clinical Neuroscience
Abstract
BACKGROUND: rTMS, particularly intermittent theta burst stimulation (iTBS), is an effective treatment for treatment-resistant depression; however, the optimal stimulation intensity remains uncertain. Clinical protocols typically use intensities between 80 and 120% of resting motor threshold (RMT), but direct comparative evidence is limited. METHODS: We conducted a retrospective analysis of 215 patients with unipolar or bipolar depression who received iTBS at either 120% RMT (n = 108) or 80% RMT (n = 107). Depression severity was assessed using the Hamilton Depression Rating Scale (HAMD-21) and Major Depression Inventory (MDI) before and after treatment. Response (≥ 50% symptom reduction) and remission (HAMD-21 ≤ 7; MDI ≤ 14) rates were compared between groups using mixed ANOVAs, with Bonferroni correction for multiple comparisons (p < .025). In addition, non-inferiority analyses were performed. RESULTS: Both groups showed large, significant symptom reductions (HAMD-21: F(1,213) = 250.98, p < .001, partial η² = 0.541; MDI: F(1,213) = 247.45, p < .001, partial η² = 0.537). No significant group effects or group × time interactions emerged for either scale. In a formal non-inferiority analysis (ANCOVA adjusting for baseline severity), 80% RMT was non-inferior to 120% RMT on the HAMD-21 (adjusted difference - 0.90, 95% CI [- 2.61, 0.82]; margin 2.25 points), a result robust across sensitivity analyses. Response rates ranged from 30.84 to 38.32% and remission rates from 23.36 to 31.48%, with no significant differences between intensity groups. Side effects occurred in 20.56% (80% RMT) versus 27.77% (120% RMT) of patients. Notably, treatment-site pain necessitating intensity reduction occurred exclusively in the 120% RMT group (n = 5, 4.6%). CONCLUSION: iTBS at 80% RMT produced antidepressant outcomes non-inferior to iTBS at 120% RMT on the HAMD-21, with supportive MDI findings and better tolerability. These findings suggest a broader intensity range for antidepressant effects of iTBS and support the systematic investigation of lower-intensity protocols.
Authors 8
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Mohamed A. Abdelnaim corresponding
Affiliation as printed
Department of Psychiatry and Psychotherapy, University of Regensburg, Universitaetsstr. 84, 93053, Regensburg, Germany. mohamed.abdelnaim@medbo.de
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Affiliation as printed
Department of Psychiatry and Psychotherapy, University of Regensburg, Universitaetsstr. 84, 93053, Regensburg, Germany
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Affiliation as printed
Department of Psychiatry and Psychotherapy, University of Regensburg, Universitaetsstr. 84, 93053, Regensburg, Germany
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Affiliation as printed
University Medical Center, University of Regensburg, Regensburg, Germany
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Affiliation as printed
Department of Psychiatry and Psychotherapy, University of Regensburg, Universitaetsstr. 84, 93053, Regensburg, Germany
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University of Regensburg · RWTH Aachen University
Affiliation as printed
Department of Psychiatry and Psychotherapy, University of Regensburg, Universitaetsstr. 84, 93053, Regensburg, Germany
Department of Psychiatry, Psychotherapy and Psychosomatics, Medical Faculty, RWTH Aachen University, Aachen, Germany
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Universität der Bundeswehr München · University of Regensburg
Affiliation as printed
Department of Psychiatry and Psychotherapy, University of Regensburg, Universitaetsstr. 84, 93053, Regensburg, Germany
Department of Psychology, University of the Bundeswehr Munich, Neubiberg, Germany
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Affiliation as printed
Department of Psychiatry and Psychotherapy, University of Regensburg, Universitaetsstr. 84, 93053, Regensburg, Germany
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