Use of Functional Neuroimaging Biomarkers as Early Predictors of Response to Theta-burst Stimulation Treatment in Depression

Depressive disorders are among the leading causes of incapacity and disability worldwide. The burden of depression is expected to increase and is associated with negative impact on clinical conditions and physical and cognitive abilities. Given the limited efficacy of antidepressant drugs, novel treatments such as theta-burst brain stimulation (TBS), a form of repetitive transcranial magnetic stimulation (rTMS), are being developed. However, to further advance the field towards treatment personalisation, increasing understanding of TBS antidepressant mechanisms and identifying treatment responders are important issues. Moreover, no studies have used neuroimaging in TBS trials in depression yet. Our group in Brazil is a leading brain stimulation centre, although neuroimaging expertise is lacking. We will conduct an open label trial designed to treat adult depression with TBS. Our aim is to build capacity in neuroimaging analyses by performing magnetic resonance imaging (MRI) assessments at baseline and after 7-10 days of treatment onset in 70 patients. The scientific goal is to test a hypothesis about treatment action: that TBS will reduce negative bias (which causally maintains negative mood) after 1 week of treatment, and patients who show this neurocognitive change will be the ones who go on to respond clinically after 6 weeks. Scientifically, this proposal and its outcomes will help advance towards next-generation precision brain stimulation, by incorporating cognitive/neuroimaging readouts that inform about mechanism and individual response.