A feasibility study of sequenced TMS and TBS dosing in adolescents with major depressive disorder.

This feasibility study focused on a staged approach to transcranial magnetic stimulation (TMS) interventions for adolescents with depression. Adolescents (N = 6) who did not respond to standard TMS were offered a two-week course of either continuous or intermittent theta burst stimulation (TBS) based on an intracortical facilitation - (ICF) biomarker. A within-subjects linear mixed model analysis of repeated measures was conducted to assess changes in depressive symptoms using the Children's Depression Rating Scale-Revised (CDRS-R). The analysis revealed a significant overall improvement in depressive symptoms from baseline to 6-month follow-up (p = 0.02; d=0.82). Significant pairwise comparisons were observed between baseline and week 2 [LSM decrease = -5.83 (SE = 2.`21), adjusted p = 0.04], and between baseline and 6-month follow-up [LSM decrease = -18.39 (SE = 7.05), adjusted p = 0.04]. There is a theoretical rationale for the use of ICF to guide dosing of TBS and this study suggests feasibility. While this study does not provide evidence to support the utility of the ICF biomarker, it may provide a template for future studies.