Predicting final TMS outcomes from symptom trajectory during treatment

Background Symptom improvement during TMS treatment may predict treatment response, but it remains unclear if this early change is clinically useful. Objective To evaluate the predictive value of symptom improvement during TMS treatment for outcomes in patients receiving TMS for major depressive disorder who have not yet achieved response criteria. Methods We retrospectively analyzed clinical data from 458 patients treated with Brainsway H1 coil targeting dorsolateral prefrontal cortex. Quick Inventory for Depressive Symptomatology (QIDS) was collected before treatment 10, 20, 30, and 36. Analyses included logistic regression predicting responder status by treatment end from symptom improvement during TMS treatment, linear regression predicting QIDS change at treatment end from QIDS change during treatment; and multiple regression to test whether individual symptom improvement predicts final improvement. Results Symptom improvement during TMS treatment predicted higher probability of final response, with model discrimination increasing from treatment 10 (T10) to treatment 20 (T20), but no further increase at treatment 30 (T30). In a leave-one-out cross-validation, there was strong correlation between early and final predicted percent QIDS change at treatment 36 based on early improvement at T10 (R=0.42, p