The Effect of Transcranial Direct Current Stimulation (tDCS) in Improving Emotion Health

NCT ID: NCT07319143

Last Updated: 2026-01-06

Basic Information

• Recruitment Status: RECRUITING
• Clinical Phase: NA
• Total Enrollment: 90 participants
• Study Classification: INTERVENTIONAL
• Study Start Date: 2025-11-05
• Study Completion Date: 2027-04-01

Brief Summary

The goal of this clinical trial is to investigate how transcranial direct current stimulation (tDCS) affects emotion functions in young adults aged 18-35 from the local community, including both male and female participants. The main question[s] it aims to answer are:

• Does tDCS improve emotional functions, such as mood regulation and motivation, in individuals with subthreshold depression (StD)?
• Can tDCS enhance emotional regulation compared to a sham stimulation (placebo)?

Researchers will compare participants receiving tDCS on either the left dorsolateral prefrontal cortex (lDLPFC) or right ventrolateral prefrontal cortex (rVLPFC) with those receiving sham stimulation to see if tDCS has a stronger effect on emotional functions.

Participants will:

• Complete online and in-person screening to assess depressive symptoms using the Chinese version of the Beck Depression Inventory II (C-BDI-II) and be selected based on their depressive symptoms (C-BDI-II score ≥ 13).
• Be randomly assigned to one of three groups: lDLPFC tDCS, rVLPFC tDCS, or Sham control group (1:1:1 ratio).
• Receive 10 sessions of tDCS or Sham tDCS over 2 weeks, with each session lasting 20 minutes.
• Complete assessments at baseline, post-intervention, 1-month follow-up, and 3-month follow-up, with each assessment lasting 2-2.5 hours. This includes questionnaires and perform emotional and cognitive tasks.

Conditions

Subthreshold Depression; Positive Emotions; Negative Emotions; Anhedonia

Study Design

• Allocation Method: RANDOMIZED
• Intervention Model: PARALLEL
• Primary Study Purpose: TREATMENT
• Blinding Strategy: DOUBLE

Study Groups

IDLPFC

This intervention is a 20 minutes per session, two-week tDCS neuromodulation of IDLPFC region (anode: F3, cathode: FP2) designed to reduce depressive symptoms via enhancing positive emotion functions, thereby reducing anhedonia.

Group Type: EXPERIMENTAL

Transcranial Direct Current Stimulation

Intervention Type: DEVICE

TDCS is a non-invasive, safe, inexpensive, convenient and effective method to modulate brain and emotion functions. During tDCS, a mild electric current is passed between the anodal and cathodal electrodes on the scalp, which respectively excites and inhibits local and downstream neuronal activity, as well as modulating interregional connectivity strength. Compared to other neurostimulation methods such as Transcranial Magnetic Stimulation, tDCS side effects tend to be milder and transient, even if being administered for multiple sessions, making it suitable to be widely applied on clinical and subclinical populations.

rVLPFC

This intervention is a 20 minutes per session, two-week tDCS neuromodulation of rVLPFC region (anode: F6, cathode: FP1) designed to reduce depressive symptoms via regulating negative emotion functions, thereby reducing depressed mood.

Group Type: EXPERIMENTAL

Transcranial Direct Current Stimulation

Intervention Type: DEVICE

TDCS is a non-invasive, safe, inexpensive, convenient and effective method to modulate brain and emotion functions. During tDCS, a mild electric current is passed between the anodal and cathodal electrodes on the scalp, which respectively excites and inhibits local and downstream neuronal activity, as well as modulating interregional connectivity strength. Compared to other neurostimulation methods such as Transcranial Magnetic Stimulation, tDCS side effects tend to be milder and transient, even if being administered for multiple sessions, making it suitable to be widely applied on clinical and subclinical populations.

Sham

This is a 20 minutes per session, two-week Sham comparator of IDLPFC/rVLPFC region, participants will receive tDCS for 90 seconds at either IDLPFC/rVLPFC at the beginning of each session to stimulate real neuromodulation.

Group Type: SHAM_COMPARATOR

Transcranial Direct Current Stimulation

Intervention Type: DEVICE

TDCS is a non-invasive, safe, inexpensive, convenient and effective method to modulate brain and emotion functions. During tDCS, a mild electric current is passed between the anodal and cathodal electrodes on the scalp, which respectively excites and inhibits local and downstream neuronal activity, as well as modulating interregional connectivity strength. Compared to other neurostimulation methods such as Transcranial Magnetic Stimulation, tDCS side effects tend to be milder and transient, even if being administered for multiple sessions, making it suitable to be widely applied on clinical and subclinical populations.

Interventions

Transcranial Direct Current Stimulation

TDCS is a non-invasive, safe, inexpensive, convenient and effective method to modulate brain and emotion functions. During tDCS, a mild electric current is passed between the anodal and cathodal electrodes on the scalp, which respectively excites and inhibits local and downstream neuronal activity, as well as modulating interregional connectivity strength. Compared to other neurostimulation methods such as Transcranial Magnetic Stimulation, tDCS side effects tend to be milder and transient, even if being administered for multiple sessions, making it suitable to be widely applied on clinical and subclinical populations.

Intervention Type: DEVICE

Other Intervention Names

tDCS

Eligibility Criteria

Inclusion Criteria

• Age 18-35 years
• Fluency in Cantonese or Mandarin
• Normal or corrected-to-normal vision and hearing
• IQ > 75% Quantile in Raven's SPM
• At least 9 years of formal education
• Right-handedness

Exclusion Criteria

• Past or current major physical illness or psychiatric disorders
• Use of psychotropic medication in the past 6 months
• Pregnancy (for women)
• Any condition that prevents safe tDCS use (e.g., brain injury, implants)
• Previous participation in neuromodulation in the past 3 months

• Minimum Eligible Age: 18 Years
• Maximum Eligible Age: 35 Years
• Eligible Sex: ALL
• Accepts Healthy Volunteers: Yes

Sponsors

Research Grants Council, Hong Kong

OTHER

Sponsor Role: collaborator

The University of Hong Kong

OTHER

Sponsor Role: lead

Responsible Party

Zhengxi Shao

Associate Professor

Responsibility Role: PRINCIPAL_INVESTIGATOR

Locations

The University of Hong Kong

Hong Kong, , Hong Kong

Site Status: RECRUITING

Countries

Hong Kong

Central Contacts

Associate Professor, Principle Investigator

Role: CONTACT

rshao@hku.hk

+852-3917-8927

Facility Contacts

Associate Professor, Principle Investigator

Role: primary

rshao@hku.hk

+852-3917-8927

Other Identifiers

17600425

Identifier Type: OTHER_GRANT

Identifier Source: secondary_id

EA240670

Identifier Type: -

Identifier Source: org_study_id