Weekly trajectories of antidepressant response to transcranial magnetic stimulation - A retrospective cohort analysis

Background: Transcranial magnetic stimulation (TMS) is an established treatment for treatment-resistant depression, yet real-world weekly response trajectories remain understudied. This retrospective study examined dual-scale weekly antidepressant response patterns in a naturalistic clinical sample. Methods: Chart review of patients with unipolar depression who received rTMS treatment in Regionspsykiatrien G & oslash;dstrup from March 2022 to July 2025. Depression severity was assessed weekly with Hamilton Depression Rating Scale-17 (HAM-D17) and Major Depression Inventory (MDI), from baseline through Week 6 (30 TMS sessions). Primary outcomes were weekly symptom changes, response and remission rates. Results: The sample comprised 56 patients (mean age 46 +/- 16.62 years, 50 % female) with moderate to severe depression (baseline HAM-D17: 22.3 +/- 5.80; MDI: 35.33 +/- 6.80) and moderate treatment resistance (Maudsley Staging Method: 7.04 +/- 1.67). Treatment completion rate was 85.7 % with a mean of 31.61 +/- 7.82 sessions. HAM-D17 showed a stepwise improvement pattern, while MDI scores showed a linear improvement. Each additional week of TMS treatment increased MDI response and remission odds >1.5 fold. HAM-D17 weekly response odds were > 2; remission odds were non-significant. At end of treatment, response rates were 20 % (HAM-D17), 16 % (MDI), and 25 % (either scale); remission rates were 13 % (HAM-D17), 25 % (MDI), and 30 % (either scale). Treatment effect sizes were large (Hedges' g > 0.9) in both scales. Conclusions: Our results support TMS effectiveness in naturalistic conditions, underscoring the importance of treatment duration in TMS treatment. The study highlights the importance of measurement-based care with multiple rating scales to capture treatment effects comprehensively. MDI was shown to be a sensitive instrument in monitoring TMS effectiveness.