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

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

Interventions

DEVICE

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.

DEVICE

Sham tDCS

The sham tDCS delivers actual stimulation for 30 seconds only, while providing similar psychological perceptions to participants as the real intervention. Thus, the sham tDCS serves as an active control condition to the tDCS interventions.

Sponsors & Collaborators

• Research Grants Council, Hong Kong

  collaborator OTHER

• The University of Hong Kong

  lead OTHER

Study Design

Allocation

RANDOMIZED

Purpose

TREATMENT

Masking

DOUBLE

Model

PARALLEL

Eligibility

Min Age

18 Years

Max Age

35 Years

Sex

ALL

Healthy Volunteers

Yes

Timeline & Regulatory

Start

2026-01-08

Primary Completion

2027-09-01

Completion

2027-09-01

Countries

• Hong Kong

Study Locations