TDCS in People with Subthreshold Depression

Not Applicable

Recruiting

• Conditions: Subthreshold Depression
• Interventions: Device: Conventional Experimental Transcranial Direct Current Stimulation (tDCS); Device: Sham Transcranial Direct Current Stimulation (tDCS); Device: Personalized Experimental Transcranial Direct Current Stimulation (tDCS)

• Registration Number: NCT06517121
• Lead Sponsor: Education University of Hong Kong

Brief Summary

This study evaluates the effects of multi-session transcranial direct current stimulation on loneliness, mood and depressiveness in people with subthreshold depression.

Detailed Description

Depression-prone individuals will be invited and allocated to three groups, either the personalised transcranial direct current stimulation (tDCS) group, the conventional tDCS group, or the sham control group. After screening and at baseline prior to the tDCS sessions, participants will complete tests and questionnaires on depression symptoms, loneliness and mood, and they will also receive functional magnetic resonance imaging (MRI) in a 3-Tesla MRI scanner. There will be a total of 10 sessions to be completed after the screening and baseline measures. For both personalised tDCS group and the conventional tDCS group, tDCS with 2 milliampere (mA) intensity will be delivered for 20 minutes in each session. For sham control group, the protocol will be similar, except that the stimulation only happens in the first 30 seconds in each session. Especially for participants allocated to the personalised tDCS group, the stimulation site for each individual in this group may vary, depending on their brain activations and connectivity. The anodal stimulation sites for participants allocated to the conventional tDCS group and the sham control group will be F3 within the left DLPFC. Immediately after and also 3-months after completing the 10 sessions, participants will be invited to complete again tests and questionnaires on depressive symptoms in addition to loneliness and mood, and they will also receive functional MRI scanning in the 3T MRI scanner. Participants will also be prompted to self-report daily their loneliness and mood levels throughout the study.

Study Timeline

• Study First Submitted: 2024-07-11
• Study First Submitted QC: 2024-07-22
• Study First Posted: 2024-07-24
• Status Verified: 2025-03
• Study Start: 2025-03
• Last Update Submitted: 2025-03-04
• Last Update Posted: 2025-03-06
• Primary Completion: 2027-01
• Study Completion: 2027-01

Recruitment & Eligibility

• Status: RECRUITING
• Sex: All
• Target Recruitment: 204

Inclusion Criteria

• No histories of learning impairment, major psychiatric disorders including Major Depressive Disorder or neurological disorders
• At least primary school education
• Subthreshold depression

Exclusion Criteria

• On medication or treatments within 2 weeks prior to the beginning of the study that would affect the individual's brain, cognitive and affective functions

Study & Design

• Study Type: INTERVENTIONAL
• Study Design: PARALLEL

Arm && Interventions

Group	Intervention	Description
Conventional tDCS group	Conventional Experimental Transcranial Direct Current Stimulation (tDCS)	Participants who are assigned to the Conventional group will receive anodal tDCS over F3.
Sham control group	Sham Transcranial Direct Current Stimulation (tDCS)	Participants who are assigned to the Conventional group will receive sham tDCS. The active stimulation will be delivered for the first 30 seconds only.
Personalised tDCS group	Personalized Experimental Transcranial Direct Current Stimulation (tDCS)	Participants who are assigned to the personalised group will receive anodal tDCS over a individualized stimulation site.

Primary Outcome Measures

Name	Time	Method
Changes in self-reported loneliness	From baseline to after the 10th tDCS session (2 weeks); from baseline to 3 months after the last tDCS session	Loneliness is assessed based on the University of California, Los Angeles (UCLA) loneliness scale (Version 3), a 20-item 4-point Likert scale (score range 20 - 80) in which higher scores indicate greater degrees of loneliness.
Changes in self-reported mood	From baseline to after the 10th tDCS session (2 weeks); from baseline to 3 months after the last tDCS session	Mood is assessed based on the Chinese Affect Scale, a 20-item 5-point Likert scale where participants rate the degree to which they currently feel the listed affects (scoring for each item: 0 = no at all; 4 = very).
Changes in depressive symptoms	From baseline to after the 10th tDCS session (2 weeks); from baseline to 3 months after the last tDCS session	Depressive symptoms are assessed based on the Hospital Anxiety and Depression Scale, a 14-item scale assessing severity of depressive and anxiety symptom (score range 0 - 21 for both subscale), with a higher scores indicating higher severity
Changes in brain activation and connectivity related to socio-affective processing	From baseline to after the 10th tDCS session (2 weeks); from baseline to 3 months after the last tDCS session	Neural activities and connectivity in Ventral Attention Network, Frontoparietal Network, and Default Mode Network are assessed by functional MRI during socio-affective task

Trial Locations

Locations (1)

The Education University of Hong Kong; 🇭🇰 Hong Kong, Hong Kong