# Technical Report: Efficacy and Safety of Low-Intensity Transcranial Magnetic Stimulation in the Remission of Depressive Symptoms in Patients With Treatment-Resistant Depression in Mexico

## TL;DR

This study shows that low-intensity transcranial magnetic stimulation safely reduces depressive symptoms in Mexican patients with treatment-resistant depression.

## Contribution

The study introduces low-intensity TMS as a novel, safe, and effective treatment for treatment-resistant depression.

## Key findings

- Li-TMS led to a significant decrease in Beck Depression Inventory scores.
- Depressive symptoms were notably lessened in participants after the treatment.
- The therapy was well-tolerated with no major adverse effects reported.

## Abstract

Transcranial magnetic stimulation (TMS) is a non-invasive neuromodulation technique that induces action potentials in the stimulated cortical area and has been approved by the Food and Drug Administration (FDA) for the treatment of major depressive disorder (MDD). The prevalence of MDD in Mexico almost tripled after the COVID-19 pandemic. In this study, we evaluated the safety and therapeutic effects of low-intensity TMS (Li-TMS) - characterized by inducing electric currents below the action potential threshold on the cerebral cortex - in 41 subjects diagnosed with treatment-resistant depression (TRD). A Li-TMS device dispensed repetitive magnetic pulses at 30 mT for 60 minutes during 20 sessions (once daily from Monday to Saturday) with the theta burst pattern. Our results suggest that Li-TMS is a safe therapy with antidepressant effects, demonstrated by the decrease in Beck Depression Inventory (BDI) scores and lessening of depressive symptoms.