Accelerated Theta Burst in Treatment-Resistant Depression: A Dose Finding and Biomarker Study

Repetitive transcranial magnetic stimulation (rTMS) is an established technology as therapy for treatment-resistant depression. The approved method for treatment is 10Hz stimulation for 40 min over the left dorsolateral prefrontal cortex (L-DLPFC). This methodology has been very successful. The limitations of this approach include the duration of the treatment (approximately 40 minutes per treatment session). Recently, researchers have aggressively pursued modifying the treatment parameters to reduce treatment times with some preliminary success. This study will investigate the efficacy of a further modified protocol, creating a more rapid form of the treatment and look at the change in neuroimaging biomarkers. In particular, this study will determine the efficacy of re-treatment in individuals who have already experienced benefit of the accelerated protocol to ensure results can be repeated.