Investigating the Efficacy and Mechanisms of Individualized tACS Targeting Anhedonia in Late-Life Depression

This project aims to explore effective treatment strategies and mechanisms of action for personalized transcranial alternating current stimulation (tACS) targeting anhedonia in late-life depression (LLD). Late-life depression has a high prevalence, with 70% of patients exhibiting symptoms of anhedonia, which is

. Current pharmacological treatments face challenges such as poor response rates and significant side effects, creating an urgent need for novel intervention strategies. As a non-invasive neurostimulation technique, tACS can improve depressive symptoms by modulating brain oscillatory activity; however, personalized treatment protocols and mechanisms specifically targeting anhedonia in LLD remain unclear. By optimizing tACS parameters, validating clinical efficacy, and elucidating the underlying neural mechanisms, this project will fill a research gap in this field. The findings will not only provide safe and effective non-pharmacological treatment options for patients with geriatric depression, thereby reducing suicide risk, but will also advance the application of tACS technology in precision medicine for mental disorders, holding significant clinical value and social implications.

Inclusion criteria

• (1) Patients were interviewed using the Structured Clinical Interview for the Diagnostic and Statistical Manual of Mental Disorders, Fifth Edition (DSM-5) - Clinical Version (SCID-5-CV) to confirm that they met the DSM-5 diagnostic criteria for "major depressive disorder"; (2) Age ≥ 60 years; gender not restricted; (3) Hamilton Depression Scale (HAMD)-17 score > 24

Exclusion criteria

• (1) History of severe head trauma or serious neurological conditions such as epilepsy; (2) Any brain devices or implants, including cochlear implants and aneurysm clips; treatments such as transcranial direct current stimulation (tDCS).

(3) Individuals who have undergone other physical modulation therapies within the past 8 weeks, including but not limited to non-convulsive electroconvulsive therapy, repetitive transcranial magnetic stimulation, and transcranial direct current stimulation.