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SchizophreniaNCT03077347

The Effects of tDCS on the Neuronal Mechanisms of Cognitive Control in Schizophrenia

A study testing Transcranial Direct Current Stimulation in people with Schizophrenia, run by University of California, Davis at 1 site in United States.

Terminated

Stopped early. The study ended before it was planned to and will not resume.

Official record
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Trial summary

The purpose of this study is to better understand the neural correlates of cognitive control (CC) deficits in schizophrenia and determine how these mechanisms can be modulated by transcranial direct current stimulation (tDCS). Read more about this study

Who is it for?
Ages 18 to 35 yearsHealthy volunteers can take part
Conditions the study is for
Schizophrenia
What is being tested?
Transcranial Direct Current Stimulation
Type of treatment
Medical device
Could I receive a placebo?
No, everyone receives an active treatment
How many people
6 participants
Where
1 siteUnited States
Study dates
1 Apr 2017to 23 Feb 2023
Phase
Interventional
Are there results?
Yes, posted in the registrySummary in the doctors' view

Key requirements

Who can take part, as listed by the sponsor. Only the study team can confirm whether you are eligible, so take this list to your doctor.

  • Ages 18 to 35 years
  • All sexes
  • Healthy volunteers accepted
  • Adult

Who may be able to join

  • Sufficient English literacy so as to be able to understand and complete cognitive tasks.
  • The ability to give valid informed consent.
  • Diagnosis of schizophrenia, schizophreniform or schizoaffective disorder (for patient group)
  • Stable outpatient or partial hospital status (for patient group)

Who cannot join

  • Psychiatric medication changes in the prior month (for patient group)
  • No psychiatric medication changes anticipated in the upcoming month (for patient group)
  • Intelligence Quotient (IQ) < 70; IQ will be measured by administering the Wechsler Abbreviated Scale of Intelligence (WASI) test.
  • People under the age of 18
  • Pregnant Women
  • Prisoners
Show all 19Show fewer
  • Pacemakers
  • Implanted brain stimulators
  • Implanted defibrillator
  • Metallic implants
  • Skin damage or skin conditions such as eczema at the sites where electrodes will be placed
  • Dreadlocks or other hair styles hindering the placement of tDCS electrodes
  • Cranial pathologies
  • Head trauma
  • Epilepsy
  • Mental retardation
  • Neurological disorders
  • Uncorrected vision problems that would hinder cognitive testing (this also pertains to subjects with color blindness in tasks where discriminating colored objects/items is necessary for successful performance).
  • Other than nicotine, no subjects reporting substance dependence in the past six months and no substance abuse in the past month

Trial locations and contacts

1 site in 1 country.

United States1 site
  • Imaging Research Center, University of California Davis Medical Center

    Sacramento, California, 95817

Other trials in United States

About this study

Official title: The Effects of Transcranial Direct Current Stimulation on the Neuronal Mechanisms of Cognitive Control in Schizophrenia

The purpose of this study is to better understand the neural correlates of cognitive control (CC) deficits in schizophrenia and determine how these mechanisms can be modulated by transcranial direct current stimulation (tDCS). CC is a critical neurocognitive process that is required for flexible, directed thought and action based on goals and intentions. Identifying and developing paradigms to improve CC is therefore a mental health priority. Current theories of CC postulate that recruitment of the dorsolateral prefrontal cortex (DLPFC) is essential for this process by maintaining high-level information that it can then use to orchestrate patterns of activation in other brain networks to support optimal performance. tDCS is a safe, noninvasive method of modulating regional brain excitability via brief (15-20 m) application of a weak (1-2 mA) current. The goal of the proposed experiments is to combine tDCS with functional magnetic resonance imaging (fMRI) to test the hypotheses that 1) acute tDCS over the DLPFC can improve performance during a CC task (the dot pattern expectancy (DPX) variant of the AX-Continuous Performance Task) in schizophrenia patients and healthy control subjects, and 2) acute tDCS over the DLPFC can increase recruitment of the DLPFC during the DPX. Effects of tDCS on brain functional connectivity (during CC as well as during the resting state) will also be examined, as well as effects on an episodic memory task. The current study will be the first to use functional magnetic resonance imaging (fMRI) to examine the effects of tDCS on the neuronal mechanisms of CC in schizophrenia, and has potentially important implications for therapeutic development for this treatment refractory yet disabling aspect of the illness.

Conditions
Schizophrenia
Keywords
Schizophrenia, Transcranial Direct Current Stimulation, tDCS, Cognitive Control, fMRI, Dorsolateral Prefrontal Cortex
Medical subject headings
Schizophrenia

What participants receive

What participants receive. In a randomised study each person is assigned to one group by chance.

  • Transcranial Direct Current StimulationDevice

    Also called tDCS

    In tDCS, saline-soaked electrodes are temporary affixed to the scalp and connected to a battery-powered current generator. A weak (2 mA) constant current is then briefly applied (~20 minutes) to stimulate the targeted brain area (e.g. the DLPFC). To control for placebo effects, the study will utilize a sham stimulation protocol that consists of very brief constant stimulation (~1 minute). Subjects usually cannot discern the difference between the sham and experimental stimulation protocols due to habituation.

Study groups in NCT03077347
Study groupRoleWhat they receive
Sham Followed by Experimental StimulationOtherSham stimulation administered followed by 24-48 hour washout, then experimental stimulation. Experimental Intervention. 20 minutes of 2 mA direct current stimulation over the dorsolateral prefrontal cortex Placebo Comparator. 1 minute of 2 mA direct current stimulation over the dorsolateral prefrontal cortex followed by 19 minutes of sham stimulation.
Receives: Device: Transcranial Direct Current Stimulation
Experimental Stimulation Followed by ShamOtherExperimental stimulation administered followed by 24-48 hour washout, then sham stimulation. Experimental Intervention. 20 minutes of 2 mA direct current stimulation over the dorsolateral prefrontal cortex Placebo Comparator. 1 minute of 2 mA direct current stimulation over the dorsolateral prefrontal cortex followed by 19 minutes of sham stimulation.
Receives: Device: Transcranial Direct Current Stimulation

What is being measured

The primary outcome is the main question the study is designed to answer.

  1. Dorsolateral Prefrontal Cortex Response

    Blood oxygen level-dependent response of the dorsolateral prefrontal cortex during a cognitive control task (Dot-Probe Expectancy Task)

    Measured: Assessment will begin immediately following stimulation and last for up to an hour.

  2. Behavioral Response

    Cognitive control-related performance (d-prime context) associated with the task (Dot-Probe Expectancy Task).

    The d-prime context index was calculated by computing a d-prime index from hits on AX trials and false alarms on BX trials as Z(H) - Z(F), with H representing hits on AX trials, F representing false alarms on BX trials, and Z representing the z-transform of a value.

    Positive d-prime values indicate more cognitive control, and negative values indicate less cognitive control.

    Measured: Assessment will begin immediately following stimulation and last for up to an hour.

Timeline

From the start of the study to its completion; the mark is today. Estimated dates are the sponsor’s plan.

  1. First posted10 Mar 2017
  2. Study start1 Apr 2017
  3. Primary completion23 Feb 2023
  4. Study completion23 Feb 2023

Why it stopped: Per request of the study PI (fyi: NOT due to adverse events).

Resources

More details

For doctors and researchers: how the study is designed, who runs it, and its registry IDs.

Study design
Study type
Interventional
Phase
Phase N/A
Primary purpose
Basic science
Allocation
Randomised
Intervention model
Crossover
Model description
Sham Stimulation followed by Direct Current Stimulation or Vice-Versa
Masking
Double blind
Who is masked
Participant, Investigator
Enrolment
6 participants (actual)
IDs, dates and publications
ClinicalTrials.gov ID
NCT03077347
Sponsor's protocol ID
1016455
Status last verified
Oct 2023
First submitted
1 Mar 2017
Last updated
13 Jun 2024
Data monitoring committee
No
FDA-regulated drug
No
FDA-regulated device
Yes
Individual data sharing
Yes: Select data from this study may be submitted to the National Institute of Mental Health Data Archive (NDA). NDA is a data repository run by the National Institute of Mental Health (NIMH) that allows researchers studying mental illness to collect and share de-identified information with each other. The data repository is accessible only to qualified investigators. All subject data will be de-identified (subject names will not be used) and each subject will have a separate identifier called a Global Unique Identifier (GUID) to remove any possibility that "the identities of the subjects cannot be readily ascertained or otherwise associated with the data by the repository staff or secondary data users" (45 Code of Federal Regulations, 46.102).

Questions about this trial

What is this clinical trial studying?

A study testing Transcranial Direct Current Stimulation in people with Schizophrenia, run by University of California, Davis at 1 site in United States.

The full registered description is in the About this study section and the official record.

Who may be eligible to take part?

The sponsor lists 4 inclusion and 19 exclusion criteria. Eligibility is decided by the study team after screening, so read the full criteria and contact a listed site.

Is this clinical trial currently recruiting?

The record says: stopped early, as of the sponsor's last update on 13 Jun 2024. Status can change between updates, so confirm with the study contact before making plans.

Where is the study taking place?

The record lists 1 site in United States. Whether a site is taking part right now should be confirmed with that site. See every site.

What are the possible benefits and risks?

They depend on the study and the treatment, and no study can promise a benefit. The study team explains the known risks during informed consent, before anyone joins; the record itself does not list them.

Are results available for this study?

Yes. Results are posted in the registry (first posted 13 Jun 2024). A summary is in the For doctors view, and the full results are on ClinicalTrials.gov.

How can a doctor refer a patient or contact the research team?

The record lists no contact. The official record names the sponsor, who can be asked directly. AzTrials does not enrol participants or take referrals.

What does the primary outcome measure?

Dorsolateral Prefrontal Cortex Response (time frame: Assessment will begin immediately following stimulation and last for up to an hour.). The study lists 2 primary outcomes in all. It is what the study was designed to measure, not a finding.

Where can I read the original study information?
Does a listing mean the treatment is approved or proven to work?

No. A listing means the study is registered. It does not show that the treatment is safe, works, or is approved by a regulator.

How often is this information updated?

AzTrials copies changed records from ClinicalTrials.gov every night and reloads the whole registry every week. The sponsor last updated this record on 13 Jun 2024.

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