Thesis defense Iris Dalhuisen (Donders Series 628)

15 November 2023

Promotor: Prof. dr. Indira Tendolkar
Co-promotor: Dr. Philip van Eijndhoven

rTMS as a treatment for depression, obstacles and opportunities

Depression is a common psychiatric disorder that is resistant to treatment in about 35% of the cases. Thus, there is a need for more effective interventions. Repetitive transcranial magnetic stimulation (rTMS) has emerged as an effective a treatment alternative. The main objective of this dissertation was (a) to assess the current state of rTMS as a treatment for depression, (b) to identify the obstacles that still need to be overcome, and (c) to identify opportunities for optimization of this treatment
option. Six knowledge gaps were identified and investigated. These gaps include (a) the optimal combination of stimulation parameters for effective treatment, (b) the relationship between neuroplastic changes and response to treatment, (c) the potential benefits of combining rTMS with specific cognitive tasks, (d) the use of functional MRI-guided neuronavigation for personalized targeting, (e) the position of rTMS within current treatment guidelines, and (f) the influence of the heterogeneous nature of depression on treatment outcomes. Based on the results of this dissertation, rTMS appears to be a valuable treatment option for patients with treatment-resistant depression. rTMS should be considered when antidepressant medication is insufficiently effective or when specific symptoms such as anxiety are prominent. Despite its effectiveness, there are still obstacles to overcome. These include improving treatment efficacy and identifying (subgroups of)
patients who would benefit most from treatment with rTMS. However, within these challenges lie opportunities for improvement; innovative developments such as personalized neuronavigation and smart use of combined interventions offer opportunities for further improving the application of rTMS in depression.