Prolonged intermittent theta burst stimulation in the treatment of major depressive disorder: a case series.

Intermittent theta burst stimulation (iTBS) using 600 pulses is an effective and FDA-cleared transcranial magnetic stimulation (TMS) protocol for major depressive disorder (MDD). Prolonged iTBS (piTBS) using 1,800 pulses could increase the effectiveness of TMS for MDD, but its real-world effectiveness is still debated. We assessed the safety, tolerability, and preliminary effectiveness of a 3x daily piTBS 1,800 pulses protocol delivered over 2 weeks in 27 participants. Only four participants (18.2%) achieved response, two of them achieving remission (9.1%). Five participants (18.5%) experienced tolerability issues. Future studies should focus on the neurophysiological effects of TBS protocols to determine optimal parameters.