Clinical Trial Details
— Status: Completed
Administrative data
NCT number |
NCT04507243 |
Other study ID # |
20-001544 |
Secondary ID |
R33MH110526 |
Status |
Completed |
Phase |
N/A
|
First received |
|
Last updated |
|
Start date |
December 1, 2020 |
Est. completion date |
March 7, 2024 |
Study information
Verified date |
April 2024 |
Source |
University of California, Los Angeles |
Contact |
n/a |
Is FDA regulated |
No |
Health authority |
|
Study type |
Interventional
|
Clinical Trial Summary
Noninvasive transcranial direct current stimulation (tDCS) is a low-intensity neuromodulation
technique of minimal risk that has been used as an experimental procedure for reducing
depressive symptoms and symptoms of other brain disorders. Though tDCS applied to prefrontal
brain areas is shown to reduce symptoms in some people with major depressive disorder (MDD),
the extent of antidepressant response often differs. Methods that map current flow directly
in the brain while a person is receiving tDCS and that determine how functional neuroimaging
signal changes after a series of tDCS sessions may help us understand how tDCS works, how it
can be optimized, and if it can be used as an effective antidepressant. Investigators will
address these questions in a two-part randomized double blind exploratory clinical trial. For
this part of the study, investigators will determine relationships between target engagement
and clinical outcomes (mood) and functional sub-constructs of cognitive control and emotion
negativity bias, and whether imaging markers at baseline predict changes in antidepressant
response.
One hundred people with depression (50 in each group) will be randomized to receive either
HD-tDCS or sham-tDCS for a total of 12 sessions each lasting 20 minutes occurring on
consecutive weekdays. At the first and last session, subjects will receive 20-30 minutes of
active or sham HD-tDCS in the MRI scanner, which will allow investigators to map tDCS
currents, and track changes in regional cerebral blood flow (rCBF) pre-to- post treatment
using completely non-invasive methods. At the first and last session and mid-way through the
trial, participants will also complete a series of clinical ratings and neurocognitive tests.
Description:
Transcranial direct current stimulation (tDCS), a noninvasive neuromodulation technique,
applied to the left dorsolateral prefrontal cortex (DLPFC) can reduce depressive symptoms and
improve cognitive control in major depressive disorder (MDD). Such findings suggest
modulation of top down prefrontal-limbic circuits, which are functionally distinct from
ventro-limbic networks and include reciprocally connected DLPFC and dorsomedial anterior
cingulate cortex (dACC). However, substantial variation in tDCS response is observed in MDD.
This may be due to imprecise stimulation protocols and suboptimal engagement of the neural
circuits mediating antidepressant response. Methods that optimize electrode placement and
account for individual variation in anatomy and that map current flow directly in the brain
may inform the mechanisms and potential clinical utility of tDCS. A new tDCS technique, high
definition (HD) tDCS, offers more focal stimulation than conventional tDCS (C-tDCS). The
degree to which C-tDCS or HD-tDCS engage dorsal prefrontal-limbic neural circuits is unknown,
yet is vital for understanding, confirming and subsequently improving possible therapeutic
effects. Innovative MRI techniques that are able to map tDCS currents in vivo and that track
changes in regional cerebral blood flow occurring with tDCS over time can provide direct
evidence of neural effects. Based on a) theoretical modeling of tDCS current flow, b) studies
showing hypo-metabolism, decreased CBF or activity in dorsal prefrontal-limbic networks, c)
modulation of these regions with treatment, and, c) our prior results showing significant
relationships in between change in dACC rCBF and clinical response to electroconvulsive
therapy (ECT), an established brain stimulation treatment, we will test for the tDCS
engagement and modulation of the DLPFC and dACC using tDCS current mapping performed in vivo
and perfusion MRI. MRI-guided neuronavigation will be used to optimize and standardize
electrode placement for DLPFC stimulation.
In this trial, using HD-tDCS that optimal target engagement of DLPFC and larger rCBF changes
in the DLPFC and dACC compared to C-tDCS in the first part of the trial, we will define
relationships between target engagement and change in mood and behavior. Patients with
moderate to severe MDD (N=100, n=50 in each group) will be randomized to Active or Sham left
anodal DLPFC HD-tDCS. Patients will complete MRI scans including tDCS current mapping and
pCASL as well as two functional imaging tasks probing cognitive control and emotion
negativity bias, recruiting prefrontal-limbic circuitry, before and after completing a 12-day
trial of 20-minute tDCS sessions.