Clinical trial NCT05937022: The Effects of Transcranial Direct Current Stimulation (tDCS) in Older Lonely Individuals
Official title: Utilizing Transcranial Direct Current Stimulation (tDCS) to Boost Social Pleasure and Participation in Older Lonely Individuals
Study type: INTERVENTIONAL
Overall status: RECRUITING
Phase: NA
Conditions: Loneliness
Keywords: Transcranial Direct Current Stimulation
Emotion Regulation
Lateral Prefrontal Cortex
Aging
Lead sponsor: The University of Hong Kong
Sponsor class: OTHER
First posted: 2023-07-10
Enrollment: 135
Sex: ALL
Minimum age (years): 60
Standard ages: ADULT
OLDER_ADULT
Accepts healthy volunteers: yes
Allocation: RANDOMIZED
Intervention model: PARALLEL
Intervention model description: Participants are assigned to three groups in parallel for the duration of the study.
Primary purpose: TREATMENT

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.

Detailed description: Loneliness, or perceived social isolation, results from discrepancies between an individual's desired and achieved social needs. A substantial proportion of older adults experience loneliness. With the social distancing policies implemented during the COVID-19 pandemic, older adults, who are more likely to be functionally dependent on their caregivers, have been primarily affected, contributing to adverse impacts on their social and emotional functions. As current loneliness interventions have shown limited efficacy, it is of great significance to test novel interventions for lonely older adults.

Transcranial direct current stimulation (tDCS) is a neuromodulatory technique that has demonstrated its safety and efficacy in modulating cortical excitability and associated behaviors in older adults. It has been suggested that repeated tDCS sessions show sustained therapeutic efficacy in chronic disorders. Additionally, the efficacy of tDCS as an intervention for lonely older adults has not been investigated. As a result, it is crucial to test repeated tDCS sessions as a potential intervention to reduce loneliness and improve socioemotional functions in lonely older adults.

Eligibility criteria: Inclusion Criteria:

1. Aged ≥ 60 years old;
2. Fluent in reading and speaking Traditional Chinese (Cantonese or Mandarin);
3. Right-handed as assessed with the Edinburgh Handedness Inventory;
4. Normal or corrected-to-normal vision and hearing;
5. Normal general cognitive function as determined by the Hong Kong version of the Montreal Cognitive Assessment (HK-MoCA) ≥ 22;
6. ≥ 9 years of formal education as lexical comprehension is required in the Emotion Rating Task.

Exclusion Criteria:

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

Primary outcomes:
measure: Changes in emotion and social motivation in response to social and non-social emotional stimuli
timeFrame: 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.
measure: Changes in self-reported loneliness levels
timeFrame: 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:
measure: Changes in social motivation
timeFrame: 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.
measure: Changes in social anhedonia
timeFrame: 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.
measure: Changes in social participation
timeFrame: 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.
measure: Changes in perceived social support
timeFrame: 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.
measure: Changes in social isolation
timeFrame: 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.
measure: Changes in positive and negative affect
timeFrame: 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.
measure: Changes in emotion regulation
timeFrame: 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.
measure: Changes in coping styles
timeFrame: 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.
measure: Changes in approach and avoidance motivation
timeFrame: 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.
measure: Changes in levels of depression
timeFrame: 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.
measure: Changes in levels of anxiety
timeFrame: 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.
measure: Changes in cognitive control functions
timeFrame: 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.
measure: Changes in processing speed
timeFrame: 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.
measure: Changes in working memory
timeFrame: 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.
measure: Changes in perceived levels of social and emotional loneliness
timeFrame: 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.
Other outcomes:
Locations:
city: Hong Kong
country: Hong Kong
facility: The University of Hong Kong
Study officials:
affiliation: The University of Hong Kong
name: Tatia Mei-chun LEE, PhD
role: PRINCIPAL_INVESTIGATOR
References: