Clinical trial NCT05342727: Transcranial Direct and Alternating Stimulation of the Prefrontal Cortex for Cognitive Improvement in Schizophrenia
Official title: The Impact of Transcranial Direct and Alternating Stimulation of the Prefrontal Cortex at Different Intensities and Frequencies on Cognition of Schizophrenic Patients
Study type: INTERVENTIONAL
Overall status: COMPLETED
Phase: PHASE1
Conditions: Schizophrenia
Cognitive Dysfunction
Keywords: schizophrenia
tDCS
tACS
Cognition
dorsolateral prefrontal cortex
Lead sponsor: The National Brain Mapping Laboratory (NBML)
Sponsor class: OTHER
Collaborators: name: Ardabil University of Medical Sciences
name: Leibniz Research Centre for Working Environment and Human Factors
First posted: 2022-04-25
Enrollment: 50
Sex: ALL
Minimum age (years): 18
Maximum age (years): 50
Standard ages: ADULT
Accepts healthy volunteers: no
Allocation: RANDOMIZED
Intervention model: PARALLEL
Intervention model description: Parallel group and each group with crossover design
Primary purpose: BASIC_SCIENCE

Brief summary: 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.

Detailed description: 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).

Eligibility criteria: 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).

Primary outcomes:
measure: Spatial Working Memory behavioral performance
timeFrame: During procedure (4 minutes)
measure: executive function behavioral performance
timeFrame: During procedure (8-10 minutes)
measure: Emotional recognition behavioral performance
timeFrame: During procedure (60 minutes)
Secondary outcomes:
measure: The Positive and Negative Affect Schedule (PANAS)
timeFrame: through study completion in each experimental session up to 1 hour
Other outcomes:
Locations:
city: Ardabil
country: Iran, Islamic Republic of
facility: Ardabil University of Medical Sciences
Study officials:
References: