Strategies for augmentation of high-frequency left-sided repetitive transcranial magnetic stimulation treatment of major depressive disorder.

<bold>Background: </bold>Repetitive Transcranial Magnetic Stimulation (rTMS) is an effective intervention for treatment-resistant Major Depressive Disorder (MDD). Early improvement during high-frequency left-sided (HFL) stimulation of the dorsolateral prefrontal cortex (DLPFC) is an important predictor of longer-term outcome, but most patients benefit later in their treatment course. We examined patients without early improvement with HFL to determine whether augmentation with additional stimulation approaches improved treatment outcome.<bold>Methods: </bold>139 participants received HFL in a measurement-based care paradigm. Participants who achieved < 20% improvement by treatment 10 could continue with HFL (N = 17) or receive one of two augmentation strategies: bilateral stimulation (BL; HFL followed by low-frequency stimulation of right DLPFC) (N = 69) or intermittent theta-burst priming of left DLPFC (iTBS-P) (N = 17) for their remaining treatment sessions. The primary outcome was the percent reduction in depressive symptoms at treatment 30.<bold>Results: </bold>Participants who achieved < 20% improvement by treatment 10 and continued with HFL showed limited benefit. iTBS-P participants had significantly greater improvement, while those receiving BL trended toward improved outcomes. Ten sessions of either augmentation strategy appeared necessary to determine the likelihood of benefit.<bold>Conclusions: </bold>Augmentation of early non-response to HFL appears to improve rTMS outcomes, with a novel iTBS-P strategy surpassing both continued HFL or BL treatment in participants with < 20% improvement after 10 treatments. These findings suggest that measurement-based care with addition of augmented stimulation for those not showing early improvement may yield superior rTMS treatment outcomes. [ABSTRACT FROM AUTHOR]