Theta burst stimulation for depressive symptoms in early-stage dementia with Lewy bodies: Protocol for a single-arm open-label feasibility study (DL-TBS Study).

Background: Depressive symptoms are highly prevalent in early-stage dementia with Lewy bodies (DLB) and are associated with impaired quality of life, functional decline, and increased caregiver burden. However, effective and well-tolerated treatment options for depression in this population remain limited because of marked drug sensitivity and autonomic dysfunction. Theta burst stimulation (TBS), a brief form of repetitive transcranial magnetic stimulation, may represent a promising non-pharmacological intervention; however, its feasibility and safety in patients with DLB have not been systematically investigated. Methods: This single-center, single-arm, open-label feasibility study will be conducted over four weeks. Participants with prodromal and mild DLB and clinically relevant depressive symptoms will receive intermittent TBS targeting the left dorsolateral prefrontal cortex three times per week for four weeks (12 sessions in total). The primary outcome is the completion rate of the 12-session TBS protocol. Secondary outcomes include safety and changes in depressive symptoms, neuropsychiatric symptoms, sleep quality, global clinical severity, cognitive function, cognitive fluctuations, extrapyramidal motor symptoms, activities of daily living, and caregiver burden. Results: This study will evaluate the feasibility and tolerability of TBS in patients with prodromal and mild DLB and will provide descriptive data on changes in clinical outcomes following the intervention. Conclusions: This study will generate critical pilot data regarding the safety and practicality of TBS for depressive symptoms in early-stage DLB. The findings will inform the design of future multicenter, randomized, sham-controlled trials aimed at establishing evidence-based non-pharmacological treatment strategies for this population with limited therapeutic options.