Modest early reduction in depression severity predicts treatment non-response with 10 Hz and accelerated theta burst repetitive transcranial magnetic stimulation in treatment-resistant depression.

Abstract Background: Repetitive transcranial magnetic stimulation (rTMS) and theta burst pattern rTMS (TBS) are evidence-based therapies for treatment-resistant depression (TRD). Randomized trials of rTMS and TBS in TRD indicate 40-50% treatment response rates. There is value in predicting the likelihood of treatment response/non-response early in rTMS and TBS treatment courses. Methods: We analysed prospective data from a multisite randomized trial (n = 299) comparing the antidepressant efficacy of 20 sessions of daily left-sided 10 Hz rTMS applied over 4 weeks with 20 sessions of accelerated bilateral TBS applied over 10 days. Depression severity was measured using the Quick Inventory of Depressive Symptomatology, clinician- and self-rated versions (QIDS-C and QIDS-SR). Negative predictive values (NPV) were generated one week into treatment using percentage QIDS improvement cut-offs as predictors for eventual non-response (< 50% improvement in QIDS at week 4 from baseline). Results: Less than or equal to 10% improvement in QIDS at week 1 had the highest NPV for treatment non-response in courses of both rTMS and accelerated TBS. The QIDS-C and QIDS-SR NPVs for daily 10 Hz rTMS at week 1 were, respectively, 77.8% and 70.0%. The QIDS-C and QIDS-SR NPVs for accelerated bilateral TBS at week 1 were, respectively, 84.6% and 84.0%. Although early non-response to accelerated TBS tended to have higher NPVs than early non-response to daily 10 Hz rTMS, differences did not reach statistical significance (P > 0.05 on chi-square and Fisher’s exact tests). Conclusion: Early treatment non-response (≤ 10% improvement in QIDS one week into treatment) can predict treatment non-response to 10 Hz rTMS and accelerated bilateral TBS with 70-85% predictive value. The early identification of potential treatment non-responders may be a practical and useful strategy to guide modification(s) to rTMS protocols and/or other optimization of individuals’ depression treatment plans to improve clinical outcomes. Research Category and Technology and Methods Clinical Research: 10. Transcranial Magnetic Stimulation (TMS) Keywords: transcranial magnetic stimulation, prediction, depression, theta burst stimulation