Skip to main content
OpenTrials
Completed

NCT Number: NCT05342727

Transcranial Direct and Alternating Stimulation of the Prefrontal Cortex for Cognitive Improvement in Schizophrenia

The purpose of this study is to investigate different stimulation intensities and frequencies of transcranial direct and alternating current stimulation over the dorsolateral prefrontal cortex for cognitive improvement in schizophrenia.

Completed

Looking for future studies?

Notify Me

Key information

Conditions

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

Age range

18 year–50 year

Sex eligibility

All sexes

Study type

Interventional

Phase

Phase 1

Primary location

Ardabil University of Medical Sciences

Ardabil, Iran

About this study

In this randomized, double-blind study, 50 patients diagnosed with schizophrenia are randomly assigned into two arms. The first group receives transcranial direct current stimulation (tDCS) at three intensities (2 mA, 3 mA, and sham) and the second group receives transcranial alternating current stimulation (tACS) at three different frequencies (8 Hz, 40 Hz, and sham) over the left dorsolateral prefrontal cortex for 20 min. There are at least 72 hours between stimulation sessions. The patients conduct three cognitive tasks from the CANTAB neuropsychological battery for schizophrenia during stimulation including a working memory task, a cognitive flexibility task, and an emotion recognition task. Mood stability is also evaluated before and after each stimulation session with the Positive and Negative Affect Scale (PANAS).

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 DSM V,
  • Being 18-50 years old (male and female)
  • If female, negative urine pregnancy test
  • feasibility for tDCS interventions according to safety guidelines
  • stable medication regime especially the classical neuroleptics and all CNS-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
  • 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) or fear of enclosed spaces).

Treatment and study plan

Transcranial direct current stimulation (tDCS)

Device

In tDCS, direct electrical currents at the intensity of interest (2 mA for example) are generated by an electrical stimulator and are noninvasively delivered to the scalp through a pair of saline-soaked sponge electrodes (7×5 cm).

transcranial alternating current stimulation (tACS)

Device

In tACS, alternating electrical currents at the frequency of interest (8 Hz for example) are generated by an electrical stimulator and are noninvasively delivered to the scalp through a pair of saline-soaked sponge electrodes (7×5 cm).

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. Emotional recognition behavioral performance

    Time frame: During procedure (60 minutes)

    Computer-morphed images derived from the facial features of real individuals, each showing a specific emotion, are displayed on the screen, one at a time. Each face is displayed for 200 milliseconds and then immediately covered up to prevent residual processing of the image. The participant must select which emotion the face displayed from 6 options (sadness, happiness, fear, anger, disgust or surprise)

Secondary outcomes

  1. The Positive and Negative Affect Schedule (PANAS)

    Time frame: through study completion in each experimental session up to 1 hour

    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

  • Ardabil University of Medical Sciences
  • Leibniz Research Centre for Working Environment and Human Factors

Registry information

Official study title

The Impact of Transcranial Direct and Alternating Stimulation of the Prefrontal Cortex at Different Intensities and Frequencies on Cognition of Schizophrenic Patients

Important dates

Study start
2021
Primary completion
2022
Study completion
2022
First posted
Apr 25, 2022
Registry last updated
Aug 8, 2022

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.

Related clinical trials

Published trials that share one or more normalized conditions with this study.