Recruiting

tDCS

Sponsor:

UCLA

Code:

NCT04267003

Conditions

Schizophrenia

Eligibility Criteria

Sex: All

Age: 18 - 47

Healthy Volunteers: Accepted

Interventions

Transcranial Direct Current Stimulation

Study Details

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 ID

NCT04267003

Start date

Jan 9, 2020

Status verified date

Mar, 2026

Completion date

Aug 31, 2026

Anticipated

Primary completion date

Aug 31, 2026

Anticipated

Eligibility Criteria

Eligibility Criteria

Sex: All

Age: 18 - 47

Healthy Volunteers: Accepted

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.

Inclusion Criteria for Patients with Schizophrenia Only:

  • 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

Study Design

Enrollment

160 participants

Anticipated

Allocation

Randomized

Intervention Model

Crossover

Primary purpose

Basic Science

Interventions and Outcome Measures

Arms

experimental: DLPFC Stimulation + Task

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

experimental: DLPFC Stimulation + Rest

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

sham comparator: 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.

sham comparator: 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.

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.

Primary outcome measure

  • EEG Correlates of Language and Cognitive Control [ Time Frame: Assessment will begin immediately following stimulation and last for about 1.5 hours. ]
  • Behavioral Response [ Time Frame: Assessment will begin immediately following stimulation and last for about 1.5 hours. ]
  • Behavioral Response [ Time Frame: Assessment will begin immediately following stimulation and last for about 1.5 hours. ]

Central Contacts and Locations

Central contacts

Molly A Bainbridge

(916) 734-8779mebainbridge@ucdavis.edu

Locations

Imaging Research Center

Recruiting

Sacramento, California, United States, 95817

Contacts

Molly Bainbridge

916-734-3749mebainbridge@ucdavis.edu

Principal Investigator:

Cameron Carter, M.D.

More Information

Sponsor

University of California, Davis

Last update posted

Mar 30, 2026

Last verified

Mar, 2026

Keywords

  • schizophrenia
  • EEG
  • tDCS
  • dorsolateral prefrontal cortex
  • cognitive control
  • transcranial direct current stimulation
  • GABA
  • MR spectroscopy

Trial information was received from ClinicalTrials.gov and was last updated on 2026-09-10. This information was provided to ClinicalTrials.gov by University of California, Davis on 2026-03-30.