RecruitingBehavioural interventionMindfulness Training During Accelerated TMS for DepressionThis NIH-funded single-arm pilot tests the feasibility, acceptability, and preliminary effects of embedding brief guided mindfulness practice (via the Waking Up smartphone app) into the inter-session intervals of clinically administered accelerated intermittent theta-burst stimulation (aiTBS) for major depressive disorder (MDD). Participants receive aiTBS as standard clinical care at MUSC; the research intervention is daily guided mindfulness practice during the aiTBS course. Outcomes include feasibility/acceptability, changes in state mindfulness and hedonic tone (Day 0 to Day 5), perceived ease of meditation, trait mindfulness at 4 and 12 weeks, and durability of antidepressant response (PHQ-9) at 4 and 12 weeks.