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| Name | Class |
|---|---|
| ki:elements | UNKNOWN |
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The goal of this study is to examine whether high-definition transcranial direct current stimulation (HD-tDCS) can influence decision-making for emotionally valenced content in younger and older adults, with or without major depression.
The main questions are:
In healthy adults, does brain stimulation modulate how people respond to emotionally valenced content during a decision-making task? What happens in the brain during modulation? Do these effects differ between younger and older adults?
In adults with depression, does brain stimulation help shift attention towards positive content during the task? What happens in the brain? Are these effects moderated by age (younger vs. older adults)?
The investigators will compare participants who receive real stimulation to those who receive sham (placebo) stimulation.
Participants will:
Receive high-definition transcranial direct current stimulation (HD-tDCS) of the dorsolateral prefrontal cortex (DLPFC)
Perform a decision-making task involving emotionally valenced words
Complete the task while undergoing a brain scan using ultra-high field 7 Tesla magnetic resonance imaging (MRI) to measure brain activity
This study investigates whether non-invasive brain stimulation influences decision-making in four groups: younger adults (20-40 years) and older adults (60-75 years), healthy or with mild to moderate major depression. Participants with personality disorders or psychosis will be excluded.
The study builds on evidence that the dorsolateral prefrontal cortex (DLPFC) plays a key role in evaluating emotionally-valenced material and decision-making. The investigators will examine whether modulation of this region through high-definition transcranial direct current stimulation (HD-tDCS) affects responses to emotionally valenced information. Stimulation will be administered differently across groups based on theoretical models of hemispheric function in mood regulation.
To explore the effect of stimulation at neurotransmitter level, the investigators will use ultra-high field 7 Tesla magnetic resonance spectroscopy (MRS) to measure Gamma-aminobutyric acid (GABA) / Glutamate concentrations in regions of interest at baseline and after stimulation. This allows to examine whether changes in inhibitory/excitatory neurotransmitters are linked to altered emotional processing and decision making.
By combining brain stimulation, ultra-high field neuroimaging, and spectroscopy, this study examines how changes in brain network activity and neurotransmitter levels relate to decision-making in health and disease. The inclusion of both younger and older adults allows the investigators to explore age-related differences in these processes.
This project aims to provide mechanistic insights into decision-making in health and disease and to support the development of targeted neuromodulation therapies that could modulate emotional processing.
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| Label | Type | Description | Intervention Names |
|---|---|---|---|
| Active Stimulation (Healthy) | Experimental | Healthy adults aged 20 to 40 or 60 to 75 years. |
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| Sham Stimulation (Healthy) | Sham Comparator | Healthy adults aged 20 to 40 or 60 to 75 years. |
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| Active Stimulation (Patient) | Experimental | Patients with mild to moderate depression aged 20 to 40 or 60 to 75 years. |
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| Sham Stimulation (Patient) | Sham Comparator | Patients with mild to moderate depression aged 20 to 40 or 60 to 75 years. |
|
| Name | Type | Description | Arm Group Labels | Other Names |
|---|---|---|---|---|
| Active high-definition transcranial direct current stimulation (HD-tDCS) - anodal F3/F4 | Device | Participants receive anodal HD-tDCS targeting the left or right DLPFC (F3/F4). |
|
| Measure | Description | Time Frame |
|---|---|---|
| Blood-oxygen-level-dependent (BOLD) signal changes during task-based functional magnetic resonance imaging (fMRI) | Blood-oxygen-level-dependent (BOLD) signal changes will be measured using ultra-high field functional magnetic resonance imaging (fMRI) during a cognitive decision-making task designed to engage prefrontal cortex regions associated with cognitive control and decision making. Structural T1-weighted and T2-weighted images will also be acquired for anatomical localization and normalization. Primary regions of interest (ROIs) include the dorsolateral prefrontal cortex (DLPFC), subgenual anterior cingulate cortex (sgACC), amygdala, and hippocampus. | During study visit; measured continuously during the 20-minute stimulation period |
| GABA concentration (baseline) | Magnetic resonance spectroscopy (MRS) will be used to measure Gamma-aminobutyric acid (GABA) concentrations in regions of interest at baseline. The goal is to examine stimulation-related neutransmitter changes. | During study visit; during a 9-minute magnetic resonance spectroscopy (MRS) session performed up to 10 minutes prior to the 20-minute stimulation period |
| GABA concentration (after stimulation) | Magnetic resonance spectroscopy (MRS) will be used to measure Gamma-aminobutyric acid (GABA) concentrations in regions of interest after HD-tDCS. The goal is to examine stimulation-related neutransmitter changes. | During study visit; within 1 minute after the 20-minute stimulation period, during a 9-minute MRS scan |
| Glutamate concentration (baseline) | Magnetic resonance spectroscopy (MRS) will be used to measure Glutamate concentrations in regions of interest at baseline. The goal is to examine stimulation-related neutransmitter changes. | During study visit; during a 9-minute magnetic resonance spectroscopy (MRS) session performed up to 10 minutes prior to the 20-minute stimulation period |
| Measure | Description | Time Frame |
|---|---|---|
| Positive Affect measured by PANAS (baseline) | Positive Affect will be assessed using the Positive Affect subscale of the Positive and Negative Affect Schedule (PANAS). This subscale includes 10 items reflecting positive emotions. Each item is rated on a 5-point Likert scale. The sum score ranges from 10 to 50, with higher scores indicating greater levels of positive affect. | During study visit; at baseline, up to two hours before the 20-minute stimulation period |
| Measure | Description | Time Frame |
|---|---|---|
| Verbal intelligence measured by Wortschatztest (WST) | The Wortschatztest (WST) is a standardized test assessing verbal intelligence by measuring vocabulary knowledge in German. It is administered to account for participants' baseline language ability, helping to control for individual differences in German word knowledge that may affect performance in the decision-making task. The maximum possible score is 42, with higher scores indicating better vocabulary knowledge. |
Inclusion Criteria (Healthy):
Exclusion Criteria (Healthy):
Inclusion Criteria (Patient):
Exclusion Criteria (Patient):
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| Name | Role | Phone | Extension | |
|---|---|---|---|---|
| Maya D Yilmaz, M.Sc. | Contact | +41 58 630 79 62 | maya.yilmaz@unibe.ch |
| Name | Affiliation | Role |
|---|---|---|
| Jessica Peter, PhD | University of Bern | Principal Investigator |
| Facility | Status | City | State | ZIP | Country | Contacts |
|---|---|---|---|---|---|---|
| University of Bern, Department of Old Age Psychiatry and Psychotherapy | Recruiting | Bern | 3000 | Switzerland |
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Data will be shared at the end of the study on a platform of the University of Bern (Boris Portal).
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Participants and experimentors are blinded to the intervention. The principal investigator managing randomization and code assignment is unblinded. Outcomes assessors remain blinded during data collection but will be unblinded after data collection is completed for final analysis.
| Sham high-definition transcranial direct current stimulation (HD-tDCS) - anodal F3/F4 | Device | Participants receive sham HD-tDCS targeting the left or right DLPFC (F3/F4). The device mimics the sensation of stimulation without delivering active current. |
|
| Active high-definition transcranial direct current stimulation (HD-tDCS) - anodal F3/ kathodal F4 | Device | Participants receive anodal HD-tDCS targeting the left DLPFC (F3) and cathodal stimulation targeting the right DLPFC (F4). |
|
| Sham high-definition transcranial direct current stimulation (HD-tDCS) - anodal F3/ kathodal F4 | Device | Participants receive sham HD-tDCS targeting the left DLPFC (F3) and right DLPFC (F4). The device mimics the sensation of stimulation without delivering active current. |
|
| Glutamate concentration (after stimulation) |
Magnetic resonance spectroscopy (MRS) will be used to measure Glutamate concentrations in regions of interest after HD-tDCS. The goal is to examine stimulation-related neutransmitter changes. |
| During study visit; within 1 minute after the 20-minute stimulation period, during a 9-minute MRS scan |
| Negative Affect measured by PANAS (baseline) | Negative Affect will be assessed using the Negative Affect subscale of the Positive and Negative Affect Schedule (PANAS). This subscale includes 10 items reflecting negative emotions. Each item is rated on a 5-point Likert scale. The sum score ranges from 10 to 50, with higher scores indicating greater levels of negative affect. | During study visit; at baseline, up to two hours before the 20-minute stimulation period |
| Positive Affect measured by PANAS (after stimulation) | Positive Affect will be assessed using the Positive Affect subscale of the Positive and Negative Affect Schedule (PANAS). This subscale includes 10 items reflecting positive emotions. Each item is rated on a 5-point Likert scale. The sum score ranges from 10 to 50, with higher scores indicating greater levels of positive affect. | During study visit; after stimulation, up to 1 hour |
| Negative Affect measured by PANAS (after stimulation) | Negative Affect will be assessed using the Negative Affect subscale of the Positive and Negative Affect Schedule (PANAS). This subscale includes 10 items reflecting negative emotions. Each item is rated on a 5-point Likert scale. The sum score ranges from 10 to 50, with higher scores indicating greater levels of negative affect. | During study visit; after stimulation, up to 1 hour |
| Storytelling (baseline) | Participants will be asked to verbally recall one positive and one negative autobiographical memory. Verbal responses will be audio recorded and analyzed using automated speech analysis. The analysis will be performed by ki:elements, an external provider specialized in speech analysis. | During study visit; at baseline, up to two hours before the 20-minute stimulation period |
| Storytelling (after stimulation) | Participants will be asked to verbally recall one positive and one negative autobiographical memory. Verbal responses will be audio recorded and analyzed using automated speech analysis. The analysis will be performed by ki:elements, an external provider specialized in speech analysis. | During study visit; after stimulation, up to 1 hour |
| During study visit; at baseline, up to two hours before the 20-minute stimulation period |
| Number of (participants with) adverse effects | Participants report adverse effects using the Adverse Effects Questionnaire. They indicate the presence and severity of possible adverse effects related to transcranial direct current stimulation (tDCS), including headache, neck pain, scalp pain, tingling, itching, burning, drowsiness, and concentration difficulties. Severity is rated on a scale from none, mild, moderate, to strong. Participants also report the perceived duration of each sensation and whether they attribute it to the stimulation. Open responses for any additional sensations are collected. | During study visit; after stimulation, up to 1 hour |
| ID | Term |
|---|---|
| D003865 | Depressive Disorder, Major |
| D003863 | Depression |
| ID | Term |
|---|---|
| D003866 | Depressive Disorder |
| D019964 | Mood Disorders |
| D001523 | Mental Disorders |
| D001526 | Behavioral Symptoms |
| D001519 | Behavior |
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