Investigating Predictors of Treatment Response in Treatment-Resistant Depression (TRD) With Interleaved TMS/fMRI

rTMS is a Health-Canada- and FDA-approved treatment for treatment-resistant depression (TRD), using focused magnetic field pulses to stimulate brain regions involved in emotion regulation, safely and non-invasively. rTMS can be applied at varying discharge frequencies which have differential effects on cortical excitability. At a low frequency (≤ 1Hz), rTMS reduces cortical excitability, while at frequencies greater than 1 Hz, rTMS facilitates cortical excitability3. In MDD, either high- frequency rTMS (HF-rTMS) applied over the left dorsolateral prefrontal cortex (DLPFC) or low- frequency rTMS (LF-rTMS) applied over the right DLPFC have similar efficacy. This study utilizes low frequency rTMS to the right DLPFC.