Computational modeling of electrical fields induced by transcranial electrical stimulation in the brains of depressed adolescents: comparison with depressed adults and practical implications

• Grant number: 22/00654-0
• Support type: Scholarships in Brazil - Scientific Initiation
• Effective date (Start): July 01, 2022
• Effective date (End): June 30, 2023
• Field of knowledge: Health Sciences - Medicine - Psychiatry
• Principal researcher: Andre Russowsky Brunoni
• Grantee: Mariana Lee Han
• Home Institution: Faculdade de Medicina (FM). Universidade de São Paulo (USP). São Paulo , SP, Brazil
• Associated research grant: 19/06009-6 - Non-implantable neuromodulation therapies: a perspective for the depressed brain, AP.TEM

Abstract

Major depressive disorder (MDD) causes large decreases in health and quality of life, with increases in health care costs, but the causes and pathogenesis of depression remain largely unknown, which greatly impedes its early detection and effective treatment. With the advancement of neuroimaging approaches, numerous functional and structural changes in the brain were detected in MDD and, more recently, attempts have been made to apply these findings to clinical practice. These neuroimaging techniques have advanced in identifying structural, functional, and neurochemical brain abnormalities that are associated with increased risk, clinical course, and treatment outcomes for major depressive disorder. Transcranial direct current stimulation (tDCS), a non-pharmacological neuromodulation technique, has proven to be a very viable new therapy for the treatment of psychiatric disorders, since, although few studies have been carried out to investigate the applicability of this method, is a non-invasive way of intervention through neurostimulation that consists of inducing the modulation of neural networks through the use of electrical currents. Traditionally, depression is treated with medication such as selective serotonin reuptake inhibitors and tricyclic antidepressants. However, these drug treatments are successful in only a third of cases after the first drug trial. Furthermore, the use of these substances is associated with side effects and resulting functional damage, even increasing the tendency to commit suicide. Therefore, in the cross-sectional study to be conducted, depressed adults and adolescents will be compared. We will use neuroimaging instruments, magnetic resonance collections from adult and adolescent patients. The computational tools to be used are SimNIBS, for realistic calculations of the electric field induced by transcranial magnetic stimulation, and FSL and FreeSurfer software for automatic generation of meshes for each tissue. The present study, therefore, aims to research and identify the variables involved in the behavior of the electric field on the brain of teenagers, in order to better understand how tDCS acts on the prefrontal cortex and, thus, to investigate the feasibility and efficacy of the clinical response obtained with the treatment in relation to major depressive disorder.