The Effects of Transcranial Direct Current Stimulation (tDCS) in Older Lonely Individuals

NCT05937022 | Unknown

• 1 other identifier: hkutdcsage
• Study Type: interventional
• Target: 135
• Locations: 1 country
• Sites: 1

Brief Summary

This randomized clinical trial aims to test the effects of 10 sessions of transcranial direct current stimulation (tDCS) on social and emotional functions in lonely older adults. The main objectives include:

• Understand whether tDCS could successfully boost positive social processing and social motivation in older adults, paralleling its effect on non-social reward processing;
• Understand whether the reduced negative and increased positive social processing in older adults would translate to an increase in real-life social activity and a decrease in loneliness feeling;
• Examine the intervention efficacy of tDCS among the aged population;
• Understand whether the tDCS effect could be long-lasting (i.e., 1 and 3 months after intervention). Participants will be lonely older adults aged 60 or above and screened on inclusion and exclusion criteria. Eligible participants will be randomly allocated to the left dorsolateral prefrontal cortex (DLPFC) tDCS group, the right ventrolateral prefrontal cortex (VLPFC) tDCS group, or the sham control group. Participants will complete an Emotion Rating Task, questionnaires assessing their psychosocial functions, and neuropsychological tests assessing their cognitive functions at baseline, after the 5th stimulation session, immediately after the 10th stimulation session, and 1 month and 3 months after the 10th stimulation session.

Conditions

Loneliness

Keywords

Transcranial Direct Current Stimulation; Emotion Regulation; Lateral Prefrontal Cortex; Aging

Outcome Measures

Primary Outcomes (2)

• Changes in emotion and social motivation in response to social and non-social emotional stimuli

  The Emotion Rating Task will assess participants' feelings and motivations upon seeing positive, negative, social, and non-social emotional words. Participants will need to rate on a scale regarding his/her emotional feelings and socializing motivation upon perceiving these words.

  From baseline to after the 5th tDCS session (1 week); from baseline to after the 10th tDCS session (2 weeks); from baseline to 1 month after the last tDCS session; from baseline to 3 months after the last tDCS session.

• Changes in self-reported loneliness levels

  Perceived level of loneliness will be assessed with the brief 6-item UCLA Loneliness Scale. All items are scored on a 4-point scale ranging from 1 (never) to 4 (often). The total score ranges from 6 to 24. A higher score indicates a higher level of perceived loneliness.

  From baseline to after the 5th tDCS session (1 week); from baseline to after the 10th tDCS session (2 weeks); from baseline to 1 month after the last tDCS session; from baseline to 3 months after the last tDCS session.

Secondary Outcomes (15)

• Changes in social motivation

  From baseline to after the 5th tDCS session (1 week); from baseline to after the 10th tDCS session (2 weeks); from baseline to 1 month after the last tDCS session; from baseline to 3 months after the last tDCS session.

• Changes in social anhedonia

  From baseline to after the 5th tDCS session (1 week); from baseline to after the 10th tDCS session (2 weeks); from baseline to 1 month after the last tDCS session; from baseline to 3 months after the last tDCS session.

• Changes in social participation

  From baseline to after the 10th tDCS session (2 weeks); from baseline to 1 month after the last tDCS session; from baseline to 3 months after the last tDCS session.

• Changes in perceived social support

  From baseline to after the 5th tDCS session (1 week); from baseline to after the 10th tDCS session (2 weeks); from baseline to 1 month after the last tDCS session; from baseline to 3 months after the last tDCS session.

• Changes in social isolation

  From baseline to after the 10th tDCS session (2 weeks); from baseline to 1 month after the last tDCS session; from baseline to 3 months after the last tDCS session.

Study Arms (3)

Right VLPFC tDCS

EXPERIMENTAL

Participants who are assigned to the right VLPFC group will receive anodal tDCS over the right ventrolateral prefrontal cortex (VLPFC).

Device: Experimental Transcranial Direct Current Stimulation (tDCS)

Left DLPFC tDCS

EXPERIMENTAL

Participants who are assigned to the right VLPFC group will receive anodal tDCS over the left dorsolateral prefrontal cortex (DLPFC).

Device: Experimental Transcranial Direct Current Stimulation (tDCS)

Sham Control tDCS

SHAM COMPARATOR

For the sham protocol, the electrode positioning will be randomly allocated to be identical to either the left DLPFC or the right VLPFC group, but the active stimulation will be delivered for the first 30 seconds only.

Device: Sham Transcranial Direct Current Stimulation (tDCS)

Interventions

Experimental Transcranial Direct Current Stimulation (tDCS) DEVICE

This study will deliver tDCS sessions for ten sessions completed within two weeks. Consecutive tDCS sessions are separated by at least 24 hours. Participants assigned to one of the two experimental groups will receive 20 minutes of active stimulation with a 2mA intensity over the corresponding brain regions.

Left DLPFC tDCS; Right VLPFC tDCS

Sham Transcranial Direct Current Stimulation (tDCS) DEVICE

This study will deliver tDCS sessions for ten sessions completed within two weeks. Consecutive tDCS sessions are separated by at least 24 hours. Participants assigned to the sham control group will receive 30 seconds of active stimulation over brain regions identical to either the left DLPFC or the right VLPFC experimental tDCS group.

Sham Control tDCS

Eligibility Criteria

• Age: 60 Years+
• Sex: all
• Healthy Volunteers: Yes
• Age Groups: Adult (18-64), Older Adult (65+)

You may qualify if:

• Aged ≥ 60 years old;
• Fluent in reading and speaking Traditional Chinese (Cantonese or Mandarin);
• Right-handed as assessed with the Edinburgh Handedness Inventory;
• Normal or corrected-to-normal vision and hearing;
• Normal general cognitive function as determined by the Hong Kong version of the Montreal Cognitive Assessment (HK-MoCA) ≥ 22;
• ≥ 9 years of formal education as lexical comprehension is required in the Emotion Rating Task.

You may not qualify if:

• Current or past major physical or neurological illness that significantly affects the individual's current cognitive, motor, or brain function;
• Medication or other treatment received within 2 weeks before the study that may affect the individual's current cognitive, motor, or brain function;
• Receiving maintained therapy that may affect cognitive, motor, or brain function and cannot be discontinued for the entire course of study;
• Past or present major psychological conditions, including affective disorders, anxiety disorder, psychotic disorder, addiction, and impulse control disorder;
• Any contraindication of tDCS, such as a cerebral implant or history (either personal or family) of seizure.
• Participation in similar brain stimulation studies within the past six months.

Sponsors & Collaborators

• The University of Hong Kong: lead

Study Sites (1)

The University of Hong Kong

Hong Kong, Hong Kong

RECRUITING

MeSH Terms

Conditions

Emotional Regulation

Condition Hierarchy (Ancestors)

Self-Control; Social Behavior; Behavior

Study Officials

• Tatia Mei-chun LEE, PhD

  The University of Hong Kong

  PRINCIPAL INVESTIGATOR

Central Study Contacts

Tatia Mei-chun LEE, PhD

CONTACT

(852) 3917-8394; tmclee@hku.hk

Study Design

• Study Type: interventional
• Phase: not applicable
• Allocation: RANDOMIZED
• Masking: SINGLE
• Who Masked: PARTICIPANT
• Masking Details: Participants will be unaware of their group assignment.
• Purpose: TREATMENT
• Intervention Model: PARALLEL
• Sponsor Type: OTHER
• Responsible Party: PRINCIPAL INVESTIGATOR
• PI Title: Director, State Key Laboratory of Brain and Cognitive Sciences; Chair Professor of Psychological Science and Clinical Psychology; May Endowed Professor in Neuropsychology.

Model Details: Participants are assigned to three groups in parallel for the duration of the study.

Study Record Dates

• First Submitted: June 8, 2023
• First Posted: July 10, 2023
• Study Start: December 3, 2022
• Primary Completion: December 1, 2024
• Study Completion: December 1, 2025
• Last Updated: July 12, 2023

Record last verified: 2023-07

Data Sharing

• IPD Sharing: Will not share

Locations

HK (1)