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.
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
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
- Being tested
- Transcranial Direct Current Stimulation
- 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 group | Role | What they receive |
|---|---|---|
| Sham Followed by Experimental Stimulation | Other | Sham 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 Sham | Other | Experimental 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.
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.
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.
- First posted10 Mar 2017
- Study start1 Apr 2017
- Primary completion23 Feb 2023
- Study completion23 Feb 2023
Why it stopped: Per request of the study PI (fyi: NOT due to adverse events).
Resources
- Official record on ClinicalTrials.govThe registry entry this page is built from, with its full change history.
- Posted resultsParticipant flow, outcome measures and adverse events reported by the sponsor.
- Other trials for SchizophreniaStudies of the same condition, open and under way.
- More trials run by University of California, DavisThe sponsor's other registered studies.
- What the trial phases meanHow a treatment moves from first tests in people to approval.
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)
Sponsor and investigators
- Lead sponsor
- University of California, Davis
- Sponsor type
- University, hospital or other
- Responsible party
- Sponsor
- Investigators
- Cameron Carter, M.D., Study director, University of California, Davis
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
- Results posted
- Yes, on ClinicalTrials.gov
- 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).
Study at a glance
From the registry record, last updated by the sponsor on 13 Jun 2024. Recruitment status is as the sponsor reported it: confirm with the study team.
- Official title
- The Effects of Transcranial Direct Current Stimulation on the Neuronal Mechanisms of Cognitive Control in Schizophrenia
- ClinicalTrials.gov ID
- NCT03077347
- Acronym / sponsor ID
- 1016455
- Conditions
- Schizophrenia
- Keywords
- Schizophrenia, Transcranial Direct Current Stimulation, tDCS, Cognitive Control, fMRI, Dorsolateral Prefrontal Cortex
- Study type
- Interventional
- Recruitment status
- TerminatedReason stopped: Per request of the study PI (fyi: NOT due to adverse events).
- Enrolment
- 6 participants (actual)
- Lead sponsor
- University of California, DavisUniversity, hospital or other
- Study start
- 1 Apr 2017 (actual)
- Primary completion
- 23 Feb 2023 (actual)
- Study completion
- 23 Feb 2023 (actual)
- First posted
- 10 Mar 2017 (actual)
- Results
- Posted 13 Jun 2024
Clinical summary
The research question as the sponsor registered it. This describes what the study plans to test, not what it found.
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.
Study design
- Primary purpose
- Basic science
- Allocation
- Randomised
- Intervention model
- Crossover
- Masking
- Double blind (participant, investigator)
- Number of arms
- 2
- Model description
- Sham Stimulation followed by Direct Current Stimulation or Vice-Versa
| Arm | Type | Receives |
|---|---|---|
| Sham Followed by Experimental Stimulation | Other | Device: Transcranial Direct Current StimulationSham 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. |
| Experimental Stimulation Followed by Sham | Other | Device: Transcranial Direct Current StimulationExperimental 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. |
Who may qualify
- Ages
- 18 to 35 years
- Sex
- All
- Healthy volunteers
- Accepted
- Age groups
- Adult
Key inclusion criteria (4 listed)
- 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)
Key exclusion criteria (19 listed)
- 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
Eligibility is decided by the study team after screening; this overview does not establish that a patient qualifies. Full inclusion and exclusion criteria.
Interventions
| Intervention | Type | Arms |
|---|---|---|
| Transcranial Direct Current StimulationAlso: tDCSIn 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. | Device | Experimental Stimulation Followed by Sham, Sham Followed by Experimental Stimulation |
Primary outcome
Dorsolateral Prefrontal Cortex Response
Time frame: Assessment will begin immediately following stimulation and last for up to an hour.
Blood oxygen level-dependent response of the dorsolateral prefrontal cortex during a cognitive control task (Dot-Probe Expectancy Task)
Behavioral Response
Time frame: Assessment will begin immediately following stimulation and last for up to an hour.
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.
Results and safety
Loading the posted results from ClinicalTrials.gov…
Research links
- Official record on ClinicalTrials.govLast updated by the sponsor 13 Jun 2024.
- Posted resultsParticipant flow, baseline, all outcome measures and adverse events.
- Individual participant dataSharing planned: 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).
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Referral and contact
AzTrials does not enrol participants or take referrals. Contact the study team or a site listed below; they decide who can take part. This study is not recruiting at the moment.
Cameron Carter, M.D. study director
University of California, Davis
1 site in 1 country: see every site and its status.
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.