Mechanisms and clinical applications of transcranial alternating current stimulation in the treatment of neuropsychiatric disorders: Current evidence and future directions

As a noninvasive brain stimulation technique, transcranial alternating current stimulation (tACS) can stimulate cortical neurons with sinusoidal and biphasic alternating current, which is expected to become an innovative neuromodulatory intervention for brain-related diseases. tACS primarily modulates the synchronization and desynchronization of neuronal electrical activity through low-intensity alternating current at specific frequencies, which regulates cortical excitability, alters endogenous cortical rhythms, and subsequently influences brain function. In recent years, tACS technology has been applied in clinical studies targeting various psychiatric and neurological disorders, demonstrating preliminary progress. However, the current research has focused mainly on feasibility studies and case analyses, while the effectiveness and safety of tACS modulation strategies require rigorous scientific validation. In the future, it will be necessary to conduct more high-quality, multicenter, large-sample randomized controlled double-blind trials targeting the different dysfunctions of patients with neuropsychiatric disorders and screen for optimal treatment parameters and stimulation sites to achieve the best neuromodulation effect. This article reviews the potential mechanisms, research progress, and factors influencing the therapeutic efficacy of tACS in the treatment of neuropsychiatric disorders. Furthermore, we discuss the existing challenges and future development trends in this field, aiming to provide novel insights and strategies for the clinical treatment and scientific investigation of neuropsychiatric disorders.