Effect of a 10-day transcutaneous trigeminal nerve stimulation (TNS) protocol for depression amelioration: A randomized, double blind, and sham-controlled phase II clinical trial

Abstract

BackgroundMajor depressive disorder (MDD) is one of the leading causes of disability in the world. However, treatment options are still limited, and marked by high refractoriness rates, new approaches are needed to optimize clinical improvement. Trigeminal nerve stimulation (TNS) is an innovative neuromodulation strategy consisting on the application of an electric current over the trigeminal nerve that propagates stimuli towards brain areas involved in mood control. ObjectiveWe examined the effects of TNS in MDD after a 10-day experimental protocol. MethodsThis was a randomized, double blind, and sham-controlled phase II study with 24 patients with severe MDD. Patients underwent a 10-day intervention protocol and were assessed with the 17-item Hamilton Depression Rating Scale (HDRS-17) at following three observation points: baseline (T1), after 10 days (T2), and after one month of the last stimulation session (T3). Main clinical outcome analysis of variance (ANOVA) was performed. ResultsPatients in the active group presented a mean reduction of 36.15% in depressive symptoms after the stimulation protocol. There was a significant interaction between group and time regarding HDRS-17 scores (F = 3.18; df = 2; p = 0.0456). Post hoc analyses exhibited a statistically significant difference between active and sham group symptoms at T2 (p = 0.040) and T3 (p = 0.026), which highlights the sustained amelioration of depressive symptoms. ConclusionThe present study found amelioration of depressive symptoms for patients undergoing a 10-day stimulation protocol of TNS, and this was sustained after one month of follow-up.