Real world transcranial magnetic stimulation for major depression: A multisite, naturalistic, retrospective study

Background: In 2008, the U.S. FDA approved rTMS as a treatment against medication-resistant depression. However, real-world rTMS outcomes remain understudied. This study investigates how rTMS for depression is delivered in routine clinical practice in France, and measures its effectiveness as well as its moderators. Methods: Five centers provided retrospective data on patients who were treated with rTMS for treatment-resistant depression from January 2015 to December 2020. Patients were assessed twice using a hetero-questionnaire, with baseline and immediate post-treatment assessments. We conducted univariate analyses to study which factors were significantly associated with rTMS effectiveness. We then included age, gender, and significant factors in a multivariate model. Results: We collected data from 435 patients with a mean age of 51.27 (14.91): 66 % were female, and 26 % suffered from bipolar depression. Stimulation was delivered using four different stimulation parameters: 1 Hz (7 % of the individuals), 10 Hz (43 %), 20 Hz (12 %), and 50 Hz (intermittent Theta Burst Stimulation, iTBS) (38 %). The mean improvement of depressive symptoms was 33 % (p < 0.001, effect-size: 0.79). Response and remission rates were of 31 % and 22.8 %, respectively. In the multivariate analysis, improvement in depressive symptoms was associated with higher baseline symptoms. Conclusion: This is one of the largest studies that investigates, with careful clinician-rated scales by trained psychiatrists, the effect of rTMS in naturalistic settings. Repetitive TMS appears to be effective in routine clinical practice, although its efficacy could be improved by analyzing predictors of response, as well as personalized targeting of specific brain areas.