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Completed

NCT Number: NCT06155786

Cognitive Effects of tDCS and tRNS in Schizophrenia

The purpose of this study is to investigate the cognitive effects of different electrical stimulation modalities, such as transcranial direct and random-noise stimulation over the dorsolateral prefrontal cortex, in schizophrenia.

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Key information

Conditions

Schizophrenia Cognition Disorders Cognitive Dysfunction Cognitive Impairment Mental Disorders Neurocognitive Disorders Schizophrenia Spectrum and Other Psychotic Disorders

Age range

18 year–50 year

Sex eligibility

All sexes

Study type

Interventional

Phase

Not applicable

Primary location

Payame Noor University, Tehran Branch, Tehran, Iran

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Who can participate

Healthy volunteers accepted: No

Only the study team can determine whether someone qualifies for participation.

Inclusion criteria

  • Diagnosis of schizophrenia based on Diagnostic and Statistical Manual (DSM)5
  • Being 18-50 years old (male and female)
  • If female, negative urine pregnancy test
  • feasibility for tDCS/tRNS interventions according to safety guidelines
  • stable medication regime, especially for classical neuroleptics and all central nervous system activating medications, if taken, 4-6 weeks before the experiment
  • fluency in the native language
  • right-handed
  • Required written informed consent signed by patients' guardian

Exclusion criteria

  • pregnancy
  • alcohol or substance dependence
  • comorbid bipolar disorder and mood disorder
  • history of seizure
  • history of neurological disorder
  • history of head injury
  • Presence of ferromagnetic objects in the body that are contraindicated for brain stimulation of the head (pacemakers or other implanted electrical devices, brain stimulators, some types of dental implants, aneurysm clips, metallic prostheses, permanent eyeliner, implanted delivery pump, or shrapnel fragments)

Treatment and study plan

transcranial direct current stimulation (tDCS) active stimulator

Device

In tDCS the electrical current is applied directly between electrodes mounted on the head which can can de-or hyperpolarizes resting membrane potential and thereby modulate cortical excitability

transcranial random noise stimulation (tRNS)

Device

Here, an alternating electrical current is applied at a mix of frequencies it is called transcranial random noise stimulation (tRNS), which can be delivered in low (between 0.1-100 Hz) or high (between 101-640 Hz) frequency stimulation

transcranial direct current stimulation (tDCS) sham stimulator

Device

Here a sham electrical current is applied directly between electrodes mounted on the head which can can de-or hyperpolarizes resting membrane potential and thereby modulate cortical excitability

Primary outcomes

  1. Spatial Working Memory behavioral performance

    Time frame: During procedure (4 minutes)

    The test begins with a number of coloured squares (boxes) shown on the screen. The aim of this test is that by selecting the boxes and using a process of elimination, the participant should find one yellow 'token' in each of a number of boxes and use them to fill up an empty column on the right-hand side of the screen.

  2. executive function behavioral performance

    Time frame: During procedure (8-10 minutes)

    The participant is shown two displays containing three coloured balls. The test administrator first demonstrates to the participant how to move the balls in the lower display to copy the pattern in the upper display and completes one demonstration problem, where the solution requires one move. The participant must then complete three further problems, one each requiring two moves, three moves, and four moves. Next, the participant is shown further problems and must work out in their head how many moves the solutions require and then select the appropriate box at the bottom of the screen to indicate their response

  3. The Positive and Negative Affect Schedule (PANAS)

    Time frame: through study completion, an average of 3 weeks

    The Positive and Negative Affect Schedule (PANAS) is a self-report questionnaire that consists of two 10-item scales to measure both positive and negative affect. Each item is rated on a 5-point scale of 1 (not at all) to 5 (very much).

Sponsors and collaborators

Lead sponsor

The National Brain Mapping Laboratory (NBML)

Other

Collaborators

  • Leibniz Research Centre for Working Environment and Human Factors
  • Payame Noor University
  • RWTH Aachen University

Registry information

Official study title

Cognitive Effects of Transcranial Direct Current Stimulation (tDCS) and Transcranial Random Noise Stimulation (tRNS) in Schizophrenia: A Random, Crossover Study

Important dates

Study start
2023
Primary completion
2023
Study completion
2024
First posted
Dec 4, 2023
Registry last updated
Mar 18, 2026

OpenTrials presents study information sourced from ClinicalTrials.gov. The official registry record should be consulted for the latest information.

View the official ClinicalTrials.gov record (opens in a new tab)

This listing is for discovery and informational purposes only. It is not medical advice, does not guarantee that a study is recruiting, and does not determine eligibility. Contact the study team and a qualified healthcare professional when considering participation.

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