To Enhance Cognition in Late Life Depression Using Transcranial Direct Current Stimulation
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|ClinicalTrials.gov Identifier: NCT02212366|
Recruitment Status : Completed
First Posted : August 8, 2014
Last Update Posted : January 24, 2018
|Condition or disease||Intervention/treatment||Phase|
|Cognition Depression||Device: Active TDCS Device: Sham TDCS||Not Applicable|
tDCS is a non-invasive brain stimulation method that utilizes low intensity electrical current either to increase cortical excitability with an anodal electrode or to suppress cortical excitability with a cathodal electrode. tDCS produces its effects through long lasting changes in neuroplasticity: in animal studies, tDCS results in long-term potentiation and brain-derived neurotrophic factor secretion; in human studies, tDCS results in potentiation of neurophysiologic markers of neuroplasticity. Consistent with these preclinical findings, tDCS to the temporoparietal cortex or left DLPFC improves memory in patients with mild to moderate Alzheimer disease(AD). tDCS has also been tested among patients with depression - including by our group - but mainly as a treatment for depressive symptoms. In one recent large study one session of bilateral anodal tDCS was shown to enhance working memory among midlife participants with major depression prior to receiving any treatment. However, it is still not known (1) whether tDCS improves cognition beyond the partial improvement that is associated with resolution of depressive symptoms; or (2) whether it has a more fundamental and long lasting effect on cognition.
This trial will assess the acute and long-term effects of a 2-week course of daily (5 days/week) bilateral anodal tDCS of the DLPFC on cognition, and in particular working memory among 36 patients with LLD. We will recruit and randomize participants who have already been treated for LLD prior to consenting to the study and who still meet criteria for remission while on antidepressant medications.
This trial will also be used as a platform to explore the effect of tDCS on neurophysiologic measures of plasticity during working memory performance. Working memory is supported by re-entrant circuits, some are local within the DLPFC and others are long-range connecting the DLPFC to more posterior cortices. These networks result in high and low frequency neuronal oscillations that can be captured by electroencephalography (EEG). Using novel neurophysiologic analyses, our group and others have demonstrated that the modulation of high-frequency (particularly gamma) oscillations by low-frequency (particularly theta) oscillations - "theta-gamma coupling" - is a neurophysiologic marker of working memory. Thus, we will explore the effect of tDCS on theta-gamma coupling.
|Study Type :||Interventional (Clinical Trial)|
|Actual Enrollment :||36 participants|
|Intervention Model:||Parallel Assignment|
|Masking:||Triple (Participant, Investigator, Outcomes Assessor)|
|Official Title:||Enhancing Cognition in Patients With Late-Life Depression: A Randomized Controlled Trial of Transcranial Direct Current Stimulation|
|Study Start Date :||May 2014|
|Actual Primary Completion Date :||November 2017|
|Actual Study Completion Date :||November 2017|
Experimental: Active TDCS
2-week course of daily (5 days/week) active bilateral anodal TDCS, duration 30 minute each session. Current 2 mA.
Device: Active TDCS
Sham Comparator: Sham TDCS
2-week course of daily (5 days/week) Sham bilateral tDCS. Duration 30 minute each session.
Device: Sham TDCS
- To compare performance on working memory task (N-Back) and neuropsychological battery between active and sham TDCS groups [ Time Frame: Two weeks following the TDCS course ]
- To compare performance on working memory task (N-Back) and neuropsychological battery between active and sham TDCS groups [ Time Frame: Three months following the TDCS course ]
- To compare theta-gamma coupling as measured by electroencephalography between active and sham TDCS groups. [ Time Frame: Two weeks following the TDCS ]
- To compare theta-gamma coupling as measured by electroencephalography between active and sham TDCS groups. [ Time Frame: 3 months following the TDCS ]
To learn more about this study, you or your doctor may contact the study research staff using the contact information provided by the sponsor.
Please refer to this study by its ClinicalTrials.gov identifier (NCT number): NCT02212366
|Center for Addiction and Mental Health|
|Toronto, Ontario, Canada, M6J1H4|
|Principal Investigator:||Tarek K Rajji, MD||Center for Addiction and Mental Health|