Functional Magnetic Resonance Imaging-Guided Personalization of Transcranial Magnetic Stimulation Treatment for Depression

Antidepressant outcomes to repetitive transcranial magnetic stimulation (rTMS) are better when stimulation is serendipitously delivered to sites of the dorsolateral prefrontal cortex (DLPFC) showing negative (anticorrelated) functional connectivity with the subgenual cingulate cortex (SGC).1-3 This suggests treatment response might be improved via prospective connectivity-guided targeting. However, DLPFC connectivity varies considerably between individuals.4 A pertinent question is whether treatment response could be improved via a single one-site-fits-all DLPFC target, representing the group average optimal site of SGC functional connectivity, or, alternatively, whether target site personalization is necessary.

We addressed this question using recently developed methodology enabling functional magnetic resonance imaging (fMRI)–guided personalized coordinates to be computed with millimeter precision.5,6 Specifically, in a sample of individuals with major depressive disorder who previously received rTMS treatment, we tested whether proximity between the clinically applied and (1) fMRI-personalized or (2) fixed group average fMRI-guided DLPFC targets were associated with treatment response. We hypothesized that closer proximity to personalized targets would be associated with improved response.