Dose Effect of a Bilateral Transcranial Magnetic Stimulation for Depression and Anxiety in a Real-World Clinical Setting

Background Transcranial Magnetic Stimulation (TMS) is a non-invasive intervention for treatment-resistant depression (TRD). Comorbid anxiety is common in TRD patients. We examined the effect of single-dose versus high-dose bilateral TMS on depression and anxiety. Methods: Seventy-eight patients received 1Hz right dorsolateral prefrontal cortex (DLPFC) stimulation combined with left single-dose or high-dose iTBS to the left DLPFC at a nonprofit clinic. Depression and anxiety symptoms were measured at baseline, after 10 and 20 sessions, and final (30-36) TMS sessions. Results: Bilateral TMS resulted in a significant decrease in depression (F(3,70)=9.670, p<.001; 74.4% response, 47.7% remission) and anxiety (F(3,70)=4.916, p=0.004, 52.6% response, 39.7% remission). The high-dose group showed a faster reduction in depression (F(3,70)=2.875, p=0.042), but not anxiety symptoms. There was no dose difference at the final session. Conclusion: Bilateral TMS improved depression and anxiety symptoms with a quicker reduction in depression symptoms with higher dosing, which highlights an important clinical consideration to reduce visits.