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Completed

NCT Number: NCT05400512

Cognitive Enhancement in Depression (The COG-D Study)

This study will investigate whether transcranial direct current stimulation (tDCS) enhances the effects of computerized cognitive training in older adults with recurrent depression (2 or more lifetime episodes; either current or within past 3 years).

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Key information

Conditions

Aging Behavior Behavioral Symptoms Cognitive Symptom Depression Nervous System Diseases Neurobehavioral Manifestations Neurologic Manifestations Pathological Conditions, Signs and Symptoms Signs and Symptoms

Age range

60 year and older

Sex eligibility

All sexes

Study type

Interventional

Phase

Not applicable

Primary location

Vanderbilt University Medical Center

Nashville, Tennessee, 37212, United States

About this study

The purpose of this study is to determine whether the addition of active tDCS to computerized cognitive remediation (nCCR) enhances brain activity and cognitive functions in older adults with recurrent depression to a greater degree than nCCR with sham stimulation. The investigators will randomize 20 elderly depressed outpatients to either double-blinded active or sham bifrontal tDCS plus daily nCCR over 4-weeks. Multimodal MRI (focused on the cognitive control network; CCN) and psychiatric and neuropsychological evaluations will be obtained at baseline and following intervention completion. Long-term CCN cognitive effects will be explored 3-months post-intervention via cognitive assessments.

Who can participate

Healthy volunteers accepted: No

Only the study team can determine whether someone qualifies for participation.

Inclusion criteria

  • Age 60+ years
  • Diagnosis of a current or past (within last 3 years) depressive episode (e.g., Major Depressive Disorder (MDD), Persistent Depressive Disorder (PDD)) using Diagnostic and Statistical Manual of Mental Disorders, Fifth Edition (DSM-5) criteria
  • In total, participants must have 2 or more lifetime depressive episodes to be considered "recurrent"
  • Either stable antidepressant regimen for at least 6 weeks or no current antidepressant treatment
  • Evidence of subjective cognitive complaints on the Everyday Cognition Scale (ECog)
  • English fluency

Exclusion criteria

  • Other Axis I psychiatric conditions via the DSM-5, except for anxiety symptoms occurring in a depressive episode
  • Acute suicidality on clinical evaluation
  • Acute grief
  • History of alcohol use disorder or substance use disorder in last 12 months
  • Currently taking medications that would significantly interact with tDCS effects (such as sodium channel blockers or anticonvulsants)
  • Neurological disorders (e.g., dementia, stroke, seizures, traumatic brain injury, Parkinson's disease)
  • Montreal Cognitive Assessment (MoCA) score < 23
  • Primary amnestic cognitive profile (>1.5 standard deviations (SDs) below demographically-adjusted mean on National Alzheimer's Coordinating Center (NACC) memory measures in context of otherwise normal cognitive profile)
  • Any physical or intellectual disability affecting ability to complete assessments
  • Unstable medical illness needing urgent treatment
  • MRI contraindications
  • Electroconvulsive therapy (ECT) or transcranial magnetic stimulation (TMS) in last 2 months
  • Current involvement in psychotherapy
  • Current involvement in other research studies (including but not limited to: neuromodulation [TMS or tDCS] or investigational drug studies)

Treatment and study plan

Cognitive training

Behavioral

Computerized cognitive training targeting the underlying cerebral networks associated with depression.

tDCS (active stimulation)

Device

A Soterix Clinical Trials Direct Current Stimulator will apply 20 minutes of 2.0 milliamps (mA) direct current through two bicarbon rubber electrodes encased in saline soaked 5 cm x 7 cm sponges (8 cc of 0.9% saline solution per sponge) placed over the frontal cortices at F3 and F4 (via 10-20 system).

tDCS (sham stimulation)

Device

Sham stimulation will be performed with the same device and all procedures will be identical except for the duration of stimulation. Participants will receive 30 seconds of 2 mA of direct current stimulation at the beginning of the session. Participants habituate to the sensation of tDCS within 30-60 seconds of stimulation. This procedure provides the same sensation of tDCS without the full duration of stimulation, making it a highly effective sham procedure.

Primary outcomes

  1. Change in task-based fMRI activation within the Cognitive Control Network during the n-back task

    Time frame: From baseline to post-intervention (4-6 weeks)

    MRI scans will be performed at baseline and after completion of the intervention. MRI will measure Cognitive Control Network function, operationalized as change in n-back functional MRI response in the anterior cingulate cortex (ACC), dorsolateral prefrontal cortex (DLPFC), and the posterior parietal cortex (PPC) regions of interest. The n-back functional MRI response is calculated as the activation difference (beta values) between 2-back and 0-back conditions of the n-back over time (post treatment - baseline). Higher scores indicate more activation.

    We will then examine correlations between the fMRI activity and n-back behavioral performance measures (accuracy, response time).

  2. Change in n-back behavioral performance (accuracy and response time)

    Time frame: From baseline to post-intervention (4-6 weeks)

    Target accuracy and response time data on the n-back will be extracted for each n-back condition (2-back and 0-back) and over time (baseline, post-intervention). Higher scores for the metrics indicate better accuracy but slower response time.

  3. Change in NIH Examiner scores

    Time frame: From baseline to post-intervention (4-6 weeks)

    This cognitive test battery assesses a range of executive functions (working memory, inhibition, set shifting, fluency, insight, and planning). The investigators will examine its Executive Composite Score, with higher scores indicate better performance.

Secondary outcomes

  1. Change in California Verbal Learning Test, 2nd edition (CVLT-2) scores

    Time frame: From baseline to post-intervention (4-6 weeks)

    The CVLT-2 is a standardized measure of verbal learning and memory, with higher scores indicative of better learning and memory performances.

Other outcomes

  1. Change in Montgomery Asberg Depression Rating Scale (MADRS) scores)

    Time frame: Baseline and weekly thereafter until post-intervention (4-6 weeks)

    Clinician-rated measure of depression severity, with higher scores indicative of greater depression severity.

Sponsors and collaborators

Lead sponsor

Vanderbilt University Medical Center

Other

Collaborators

  • American Academy of Neurology

Registry information

Official study title

Non-invasive Neuromodulation to Enhance Targeted Cognitive Remediation in Older Adults With Depression

Important dates

Study start
2023
Primary completion
2025
Study completion
2025
First posted
Jun 1, 2022
Registry last updated
Jun 3, 2026

OpenTrials presents study information sourced from ClinicalTrials.gov. The official registry record should be consulted for the latest information.

View the official ClinicalTrials.gov record (opens in a new tab)

This listing is for discovery and informational purposes only. It is not medical advice, does not guarantee that a study is recruiting, and does not determine eligibility. Contact the study team and a qualified healthcare professional when considering participation.

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