Effects of Brain Stimulation on Cognition, Oscillations and GABA Levels in Schizophrenia

NCT ID: NCT04267003

Last Updated: 2025-04-03

Basic Information

• Recruitment Status: RECRUITING
• Clinical Phase: NA
• Total Enrollment: 160 participants
• Study Classification: INTERVENTIONAL
• Study Start Date: 2020-01-09
• Study Completion Date: 2025-08-31

Brief Summary

People with schizophrenia often have problems with attention, learning and memory and other cognitive abilities that interfere with their work and school performance. Unfortunately, even our best treatments often do not significantly reduce these cognitive problems. The current study investigates whether or not delivering a very small electrical current to people's foreheads (called, transcranial direct current stimulation; (tDCS)) might improve functioning in the front part of the brain and reduce these cognitive problems in people with schizophrenia. tDCS is non-invasive and has been shown to improve cognitive functioning in some preliminary studies. The current study will investigate whether giving tDCS during a task is more effective than giving it during rest (Aim 1), whether delivery of tDCS to the front of the head is more effective than delivery to the back of the head (Aim 2), and whether tDCS delivery will alter levels of a major inhibitory neurotransmitter in the brain (GABA; Aim 3) that is important to cognitive functioning and may be disrupted in people with schizophrenia. Although this study is not intended to diagnose, cure or treat schizophrenia or any other disease, if results are positive it will encourage future large-scale studies to determine if tDCS can become an effective treatment for cognitive problems in people with schizophrenia.

Conditions

Schizophrenia

Study Design

• Allocation Method: RANDOMIZED
• Intervention Model: CROSSOVER
• Primary Study Purpose: BASIC_SCIENCE
• Blinding Strategy: DOUBLE

Study Groups

DLPFC Stimulation + Task

Intervention. 20 minutes of 2 mA direct current stimulation over the dorsolateral prefrontal cortex during cognitive task completion.

Group Type: EXPERIMENTAL

Transcranial Direct Current Stimulation

Intervention Type: DEVICE

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.

DLPFC Stimulation + Rest

Intervention. 20 minutes of 2 mA direct current stimulation over the dorsolateral prefrontal cortex during rest.

Group Type: EXPERIMENTAL

Transcranial Direct Current Stimulation

Intervention Type: DEVICE

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.

Sham Stimulation + Task

Placebo Comparator. 0.5-1 minutes of 2 mA direct current stimulation over dorsolateral prefrontal cortex followed by 19-19.5 minutes of sham stimulation, during cognitive task completion.

Group Type: SHAM_COMPARATOR

Transcranial Direct Current Stimulation

Intervention Type: DEVICE

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.

Sham Stimulation + Rest

Placebo Comparator. 0.5-1 minutes of 2 mA direct current stimulation over dorsolateral prefrontal cortex followed by 19-19.5 minutes of sham stimulation, during rest.

Group Type: SHAM_COMPARATOR

Transcranial Direct Current Stimulation

Intervention Type: DEVICE

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.

Interventions

Transcranial Direct Current Stimulation

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.

Intervention Type: DEVICE

Eligibility Criteria

Inclusion Criteria

• Participants must be able to sufficiently speak and understand English so as to be able to understand and complete cognitive tasks.
• All subjects must have the ability to give valid informed consent.

• Diagnosis of schizophrenia, schizophreniform or schizoaffective disorder
• No medication changes in the prior month
• No medication changes anticipated in the upcoming month
• Stable outpatient or partial hospital status
• Normal IQ (>70; IQ will be measured by administering the Wechsler Abbreviated Scale of
• Intelligence (WASI) test)
• Must not be currently taking the antipsychotic clozapine

Exclusion Criteria

• Pacemakers
• Implanted electrical (brain and spinal) stimulators
• Implanted defibrillator
• Metallic implants
• Skin damage or skin conditions such as eczema at the sites where electrodes will be placed
• Hair styles hindering the placement of electrodes
• Cranial pathologies
• Head trauma
• Epilepsy
• Mental retardation
• Any known history of neurological disorders (including epilepsy, amyotrophic lateral sclerosis (ALS), multiple sclerosis (MS), stroke, cerebral palsy, any DSM-5 axis I psychiatric disorder (for healthy control subjects), autism)
• 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)
• Pregnancy
• Substance dependence in the past six months
• Substance abuse in the past month

• Minimum Eligible Age: 18 Years
• Maximum Eligible Age: 47 Years
• Eligible Sex: ALL
• Accepts Healthy Volunteers: Yes

Sponsors

University of California, Davis

OTHER

Sponsor Role: lead

Responsible Party

Responsibility Role: SPONSOR

Locations

Imaging Research Center

Sacramento, California, United States

Site Status: RECRUITING

Countries

United States

Central Contacts

Molly A Bainbridge

Role: CONTACT

mebainbridge@ucdavis.edu

(916) 734-8779

Facility Contacts

Molly Bainbridge

Role: primary

mebainbridge@ucdavis.edu

916-734-3749

Related Links

https://studypages.com/s/effects-of-brain-stimulation-on-cognition-oscillations-and-gaba-levels-in-schizophrenia-205153/

Learn more or sign up for the study here!

Other Identifiers

1515202

Identifier Type: -

Identifier Source: org_study_id