Skip to main content

ORIGINAL RESEARCH article

Front. Psychiatry
Sec. Neuroimaging
Volume 15 - 2024 | doi: 10.3389/fpsyt.2024.1400414

Unilateral vs. Bilateral DLPFC rTMS: Comparative Effects on Depression, Visual-Spatial Memory, Inhibitory Control and Cognitive Flexibility in Major Depressive Disorder

Provisionally accepted
Fatemeh Asgharian Asl Fatemeh Asgharian Asl 1,2*Sajjad Abbaszade Sajjad Abbaszade 3Ladan Vaghef Ladan Vaghef 4
  • 1 University of Tabriz, Tabriz, Iran
  • 2 Division of Cognitive Neuroscience, Department of Psychology, University of Tabriz, Tabriz, Iran
  • 3 Department of Cognitive Science, Faculty of Education & Psychology, University of Tehran, Tehran, Iran
  • 4 Department of Psychology, Faculty of Education & Psychology, Azarbaijan Shahid Madani University, Tabriz, Iran, Tabriz, Iran

The final, formatted version of the article will be published soon.

    Background: Exciting left DLPFC activity with high frequency and inhibiting right DLPFC with low frequency repetitive transcranial magnetic stimulation (rTMS) has shown antidepressant effects in major depressive disorder (MDD) and executive functions. However, few studies have directly compared unilateral and bilateral protocols. Methods: Forty-seven individuals with treatment-resistant MDD underwent 10 sessions of rTMS over left DLPFC (20 Hz), bilateral DLPFC (left 20 Hz, right 1 Hz), or sham stimulation. Outcomes were depression (Beck Depression Inventory-II), visual-spatial memory (Corsi Block Test), response inhibition (Go/No-Go task), and cognitive flexibility (Wisconsin Card Sorting Test) assessed before and after treatment.Results: Both unilateral and bilateral rTMS significantly reduced depression levels versus sham controls based on BDI-II scores. While bilateral stimulation did not improve Corsi Test performance, unilateral protocol enhanced visual-spatial memory. On the Go/No-Go task, accuracy was higher in both active stimulation groups compared to sham, with no response time differences. Neither unilateral nor bilateral rTMS had significant effects on cognitive flexibility per the WCST.Conclusions: Despite comparable antidepressant effects, unilateral stimulation had some cognitive advantages over bilateral rTMS, potentially due to greater left dorsolateral prefrontal cortex excitation. Further research on parameter optimization is warranted.

    Keywords: Major Depressive Disorder, Transcranial Magnetic Stimulation, dorsolateral prefrontal cortex, Cognition, Depression, inhibition, Memory, cognitive flexibility

    Received: 13 Mar 2024; Accepted: 31 Jul 2024.

    Copyright: © 2024 Asgharian Asl, Abbaszade and Vaghef. This is an open-access article distributed under the terms of the Creative Commons Attribution License (CC BY). The use, distribution or reproduction in other forums is permitted, provided the original author(s) or licensor are credited and that the original publication in this journal is cited, in accordance with accepted academic practice. No use, distribution or reproduction is permitted which does not comply with these terms.

    * Correspondence: Fatemeh Asgharian Asl, University of Tabriz, Tabriz, Iran

    Disclaimer: All claims expressed in this article are solely those of the authors and do not necessarily represent those of their affiliated organizations, or those of the publisher, the editors and the reviewers. Any product that may be evaluated in this article or claim that may be made by its manufacturer is not guaranteed or endorsed by the publisher.