This study aims to develop a novel multimodal treatment for treatment resistant depression (TRD), which combines intermittent theta burst stimulation (iTBS), a type of FDA-approved rTMS protocol, with digital mindfulness training. We propose that this multimodal treatment will suppress posterior Default Mode Network (pDMN) brain activity as measured with electroencephalography (primary outcome and neural target), as well as enhance cognition and alleviate depression symptoms in patients with TRD. The study will determine the optimal dose required for neural target engagement by the multimodal iTBS + digital mindfulness training relative to an active control training combined with iTBS.