Transcranial Alternating Current Stimulation to Enhance Mindfulness Therapy in Generalized Anxiety Disorder

Summary

This randomized, double-blind, sham-controlled clinical trial will evaluate whether individualized alpha-frequency transcranial alternating current stimulation (tACS) can enhance the effects of mindfulness therapy in adults with generalized anxiety disorder. A total of 99 participants will be randomly assigned to one of three groups: synchronous tACS combined with mindfulness therapy, desynchronous tACS combined with mindfulness therapy, or sham tACS combined with mindfulness therapy.

All participants will receive a standardized mindfulness therapy program. The study will compare changes in anxiety symptoms, worry, mindfulness, attention control, cognitive performance, and neurophysiological measures across the three groups. Assessments will be conducted from baseline through follow-up visits to examine both clinical effects and possible neural mechanisms.

Conditions

• Generalized Anxiety Disorder (GAD)

Interventions

DEVICE

Synchronous Individualized Alpha-Frequency tACS

Individualized alpha-frequency transcranial alternating current stimulation (tACS) will be delivered to the frontoparietal network. Stimulation electrodes will be placed over F3 and P3, corresponding to the left dorsolateral prefrontal cortex and left inferior parietal lobule. In the synchronous tACS condition, the F3 and P3 stimulation electrodes will deliver in-phase sinusoidal alternating current. The stimulation frequency will be individualized based on each participant's alpha-band phase locking value peak between F3 and P3.

DEVICE

Desynchronous Individualized Alpha-Frequency tACS

Individualized alpha-frequency tACS will be delivered using the same stimulation targets and general setup as the synchronous tACS condition. Stimulation electrodes will be placed over F3 and P3, corresponding to the left dorsolateral prefrontal cortex and left inferior parietal lobule. In the desynchronous tACS condition, the phase difference between the F3 and P3 stimulation electrodes will be set at 180 degrees.

DEVICE

Sham tACS

Sham tACS will be delivered with the electrodes placed in the same positions as in the active tACS conditions. The sham condition will include 30-second ramp-up and ramp-down periods at the beginning and end of stimulation to mimic the sensation of active stimulation. No active current will be delivered during the main 20-minute stimulation period, while the electrodes will remain in place to maintain blinding.

BEHAVIORAL

Mindfulness Therapy

Participants will receive a standardized mindfulness therapy program for 2 weeks, with 10 sessions in total. Each session will last 40 minutes. The program follows a progressive structure of awareness, acceptance, and application. The first five sessions focus on breath awareness and body scan practices. The last five sessions focus on observing anxiety-related bodily sensations and worry-related thoughts with a nonjudgmental and accepting attitude, and on using breathing space practices to redirect attention to the present moment.

Sponsors & Collaborators

• Central South University

  lead OTHER

Principal Investigators

• Yan Zhang, PhD · Second Xiangya Hospital of Central South University

• Yumeng Ju, PhD · Second Xiangya Hospital of Central South University

Study Design

Allocation

RANDOMIZED

Purpose

TREATMENT

Masking

DOUBLE

Model

PARALLEL

Eligibility

Min Age

18 Years

Max Age

60 Years

Sex

ALL

Healthy Volunteers

No

Timeline & Regulatory

Start

2026-06-01

Primary Completion

2027-12-01

Completion

2028-06-01

Countries

• China

Study Locations