Therapeutic Effect of Neuromodulation on Anxiety Disorders by High-Definition Transcranial Electrical Stimulation

High-definition transcranial electrical stimulation (HD-tES) is a non-invasive brain neuromodulation technique that applies a small electrical current to the scalp to alter neural excitability and stimulate localized brain activation. Previous clinical trials have explored the use of HD-tES for treating mental health conditions such as depression, anxiety, obsessive-compulsive disorder, and post-traumatic stress disorder. This trial aims to investigate the efficacy and safety of HD-tES in ameliorating anxiety symptoms among patients with generalized anxiety disorder (GAD), thereby validating its potential as a treatment for anxiety disorders. Participants will be randomly assigned to one of four HD-tES treatment groups: (1) HD-tES inhibitory waveform (cDC+cTBS) applied to the right dorsolateral prefrontal cortex (DLPFC) for 10 minutes, followed by sham excitatory waveform (aDC+iTBS) stimulation applied to the left DLPFC for 10 minutes. (2) Sham inhibitory waveform (cDC+cTBS) stimulation applied to the right DLPFC for 10 minutes, followed by HD-tES excitatory waveform (aDC+iTBS) applied to the left DLPFC for 10 minutes. (3) HD-tES inhibitory waveform (cDC+cTBS) applied to the right DLPFC for 10 minutes, followed by HD-tES excitatory waveform (aDC+iTBS) applied to the left DLPFC for 10 minutes. (4) Sham inhibitory waveform (cDC+cTBS) stimulation applied to the right DLPFC for 10 minutes, followed by sham excitatory waveform (aDC+iTBS) stimulation applied to the left DLPFC for 10 minutes. Regardless of the group assignment, participants will undergo treatment sessions over a 2-week period, with five sessions per week and no more than one session per day. Each session lasts approximately 20 minutes. Assessments will be conducted before the treatment, weekly during the treatment period (at the end of the first and second weeks), and a follow-up evaluation will be performed one week after the conclusion of the treatment.