SchizophreniaNCT07701343
tACS for Working Memory in Schizophrenia
A study testing transcranial alternating current stimulation in people with Schizophrenia and Working Memory, run by Central South University at 1 site in China.
Trial summary
This study is a randomized, single-blind, sham-controlled crossover trial enrolling 30 schizophrenia patients, each receiving one active and one sham tACS session (7-day washout), targeting P3/P4 at individual alpha frequency (2mA, 30min) during a working memory task, with accuracy and reaction time as primary… Read more about this study
- Who is it for?
- Ages 18 to 50 years
- Conditions the study is for
- Schizophrenia, Working Memory
- What is being tested?
- transcranial alternating current stimulation
- Type of treatment
- Medical device
- Could I receive a placebo?
- Yes, some participants may receive a placebo
- How many people
- 30 participants
- Where
- 1 siteChina
- Study dates
- 6 Jul 2026to 31 Dec 2026
- Phase
- Interventional
- Are there results?
- Not yet: the study is under way
Key requirements
Who can take part, as listed by the sponsor. Only the study team can confirm whether you are eligible, so take this list to your doctor.
- Ages 18 to 50 years
- All sexes
- No healthy volunteers
- Adult
Who may be able to join
- Aged 18-50 years, meeting the Diagnostic and Statistical Manual of Mental Disorders, Fifth Edition (DSM-5) diagnostic criteria for schizophrenia, confirmed by the Structured Clinical Interview for DSM-5 (SCID-5).
- Spatial span T-score <40 on the MATRICS Consensus Cognitive Battery (MCCB).
- Taking 1-2 antipsychotic medications, with stable dosage for at least 1 week prior to enrollment. No use of mood stabilizers, antidepressants, or excessive benzodiazepines (lorazepam equivalent >2 mg/day). The type and dosage of antipsychotic medications remain unchanged during the treatment period.
- Impaired functioning in daily activities.
- Willing to participate in this study and provide written informed consent.
Who cannot join
- Previously diagnosed with or comorbid any other DSM-5 mental disorder besides schizophrenia.
- Presence of significant mood symptoms or substance use disorder (other than caffeine and/or tobacco).
- Presence of any contraindication to transcranial alternating current stimulation (tACS).
- Received other forms of electrical or magnetic stimulation therapy within 1 month prior to enrollment.
- History or current presence of any major physical illness, neurological disorder, or traumatic brain injury that may affect brain structure or function.
- Pregnant or breastfeeding women, or women planning to become pregnant during the study period.
Trial locations and contacts
1 site in 1 country. Contact the study team or a site near you to ask about taking part.
China1 site, 1 recruiting
- Recruiting
The Second Xiangya Hospital of Central South University
Changsha, Hunan, 410011
Jimin Zhang, 18738858423, zhangjimin@csu.edu.cn
About this study
Official title: Efficacy and Mechanisms of Transcranial Alternating Current Stimulation in Improving Working Memory in Patients With Schizophrenia
This study is a randomized, single-blind, sham-controlled crossover trial enrolling 30 schizophrenia patients, each receiving one active and one sham tACS session (7-day washout), targeting P3/P4 at individual alpha frequency (2mA, 30min) during a working memory task, with accuracy and reaction time as primary outcomes, alongside EEG and neurophysiological measures, to test the efficacy and mechanisms of individualized alpha-tACS on working memory.
Read the detailed description
This study is a randomized, single-blind, sham-controlled, crossover exploratory trial that plans to enroll 30 inpatients with schizophrenia, randomized 1:1 into two groups, with all participants receiving one active and one sham tACS session in a crossover manner separated by a 7-day washout. Stimulation targets the parietal P3/P4 sites at individual alpha frequency, with an intensity of 2 mA and a duration of 30 minutes per session, delivered concurrently with a working memory task (SIRP). Primary outcomes are SIRP accuracy and reaction time, with concurrent task-state EEG recording, along with assessments of clinical symptoms, cognitive function, and neurophysiological markers including ASSR, MMN, and P300. The study aims to explore the efficacy and underlying neural mechanisms of individualized alpha-tACS in improving working memory in schizophrenia.
- Conditions
- Schizophrenia, Working Memory
- Being tested
- transcranial alternating current stimulation, sham stimulation
- Keywords
- Schizophrenia, Working Memory, Transcranial Alternating Current Stimulation
- Medical subject headings
- Schizophrenia
What participants receive
What participants receive. In a randomised study each person is assigned to one group by chance.
transcranial alternating current stimulationDevice
For montage 1, active electrode at P3 (10-10 system), return electrodes at P1, P5, PO3, CP3. For montage 2, active electrode at P4, return electrodes at P2, P6, PO4, CP4. Conductive paste ensures impedance <10 kΩ. Individual alpha frequency is used, calculated before each session from mean EEG at P3/P4 during SIRP task. Stimulation intensity is 2 mA (peak-to-zero) via electric field modeling. Stimulation is delivered during SIRP task, 30 min total per session (including 15s ramp-up/down), with continuous sine wave output.
sham stimulationDevice
Sham stimulation provides only a 15-second ramp-up and ramp-down current at the beginning and end of each session to mimic the initial tingling or itching sensation on the scalp produced by real stimulation, but delivers no effective stimulation current during the main phase of the task period.
| Study group | Role | What they receive |
|---|---|---|
| sham group | Sham comparator | sham stimulation Receives: Device: sham stimulation |
| active group | Experimental | transcranial alternating current stimulation Receives: Device: transcranial alternating current stimulation |
What is being measured
The primary outcome is the main question the study is designed to answer.
Working Memory Accuracy
Assessment of task accuracy on the Sternberg Item Recognition Paradigm (SIRP). Participants are required to judge whether a probe stimulus belongs to a previously memorized set, with memory set sizes of 1 and 5. The outcome is measured as the percentage of correct responses (0-100%) across all trials, with higher scores indicating better working memory performance.
Measured: Day 1 (baseline, prior to first intervention); within 15 minutes after Session 1; Day 9 (prior to second intervention, after 7-day washout); within 15 minutes after Session 2.
Working Memory Reaction Time
Assessment of response speed on the Sternberg Item Recognition Paradigm (SIRP). Participants are required to judge whether a probe stimulus belongs to a previously memorized set, with memory set sizes of 1 and 5. The outcome is measured as the mean response latency for correct responses only, calculated from stimulus onset to the participant's button press, with shorter times indicating faster processing speed.
Measured: Day 1 (baseline, prior to first intervention); within 15 minutes after Session 1; Day 9 (prior to second intervention, after 7-day washout); within 15 minutes after Session 2.
Secondary outcomes (10)
Changes in MCCB Performance
Assessment of cognitive function using the MATRICS Consensus Cognitive Battery (MCCB), a standardized cognitive assessment tool designed for schizophrenia and other neuropsychiatric conditions. The MCCB evaluates 9 cognitive domains: attention, information processing speed, verbal learning and memory, visual learning and memory, spatial working memory, reasoning and problem solving, social cognition, executive function, and fine motor skills. The overall cognitive composite score ranges from 20 to 100 (T-score), with higher scores indicating better cognitive performance.
Measured: Baseline, on the day after each of the two interventions
Changes in Positive and Negative Symptom Scale (PANSS) Scores
Scores range from 30 to 210, with higher scores indicating more severe positive and negative symptoms.
Measured: Before and one week after each of the two interventions.
Changes in Scale for the Assessment of Negative Symptoms (SANS) Scores
Scores range from 0 to 120; higher scores indicate more severe negative symptoms.
Measured: Before and one week after each of the two interventions.
Changes in Calgary Depression Scale for Schizophrenia (CDSS) Scores
Scores range from 0 to 27; higher scores indicate more severe affective symptoms.
Measured: Before and one week after each of the two interventions.
Changes in Brain Function
Functional magnetic resonance imaging (fMRI), based on blood oxygen level-dependent (BOLD) contrast, can detect changes in blood oxygenation and analyze changes in brain function after intervention.
Measured: Baseline, on the day after each of the two interventions.
Changes in Neuroelectrophysiological Signals
Changes in neuroelectrophysiological signals are collected through task-based electroencephalography (EEG).
Measured: Baseline, 30 minutes after each of the two interventions.
Changes in 40Hz Auditory Steady-State Response (40Hz-ASSR)
The 40Hz auditory steady-state response recorded by EEG, including evoked power and inter-trial phase coherence, will be measured. The unit of measurement for evoked power is μV², and for coherence is unitless.
Measured: Baseline, 30 minutes after each of the two interventions.
Changes in Mismatch Negativity (MMN)
Mismatch negativity amplitude recorded by EEG using an oddball paradigm will be measured. The unit of measurement is microvolts (μV).
Measured: Baseline, 30 minutes after each of the two interventions.
Changes in P300 Event-Related Potential
P300 amplitude recorded by EEG using an oddball paradigm will be measured. The unit of measurement is microvolts (μV).
Measured: Baseline, 30 minutes after each of the two interventions.
Hallucination and Delusion Visual Analog Scale (HD-VAS) Score
Assessment of acute post-intervention changes in hallucination and delusion severity using a patient-rated visual analog scale (VAS). The scale consists of a 0-100 mm horizontal line, on which participants mark their current symptom severity. The distance (in millimeters) from the left anchor ("no symptoms") to the participant's mark is measured with a ruler. This scale serves as a supplementary measure to the PANSS to capture immediate symptom changes following each intervention. Scores range from 0 to 100 mm, with higher scores indicating more severe hallucinations and delusions.
Measured: Within 15 minutes after completion of Session 1; within 15 minutes after completion of Session 2.
Timeline
From the start of the study to its completion; the mark is today. Estimated dates are the sponsor’s plan.
- First posted14 Jul 2026
- Study start6 Jul 2026 (estimated)
- Primary completion31 Oct 2026 (estimated)
- Study completion31 Dec 2026 (estimated)
Resources
- Official record on ClinicalTrials.govThe registry entry this page is built from, with its full change history.
- Other trials for SchizophreniaStudies of the same condition, open and under way.
- What the trial phases meanHow a treatment moves from first tests in people to approval.
More details
For doctors and researchers: how the study is designed, who runs it, and its registry IDs.
Study design
- Study type
- Interventional
- Phase
- Phase N/A
- Primary purpose
- Treatment
- Allocation
- Randomised
- Intervention model
- Parallel groups
- Masking
- Single blind
- Who is masked
- Participant
- Enrolment
- 30 participants (estimated)
Sponsor and investigators
- Lead sponsor
- Central South University
- Sponsor type
- University, hospital or other
- Responsible party
- Principal investigator, Renrong Wu, Second Xiangya Hospital of Central South University
IDs, dates and publications
- ClinicalTrials.gov ID
- NCT07701343
- Sponsor's protocol ID
- LYG20260081
- Status last verified
- Jul 2026
- First submitted
- 2 Jul 2026
- Last updated
- 14 Jul 2026
- Results posted
- No
- Data monitoring committee
- No
- FDA-regulated drug
- No
- FDA-regulated device
- No
- Individual data sharing
- No
Study at a glance
From the registry record, last updated by the sponsor on 14 Jul 2026. Recruitment status is as the sponsor reported it: confirm with the study team.
- Official title
- Efficacy and Mechanisms of Transcranial Alternating Current Stimulation in Improving Working Memory in Patients With Schizophrenia
- ClinicalTrials.gov ID
- NCT07701343
- Acronym / sponsor ID
- LYG20260081
- Conditions
- Schizophrenia, Working Memory
- Keywords
- Schizophrenia, Working Memory, Transcranial Alternating Current Stimulation
- Study type
- Interventional
- Recruitment status
- Recruiting
- Enrolment
- 30 participants (estimated)
- Lead sponsor
- Central South UniversityUniversity, hospital or other
- Study start
- 6 Jul 2026 (estimated)
- Primary completion
- 31 Oct 2026 (estimated)
- Study completion
- 31 Dec 2026 (estimated)
- First posted
- 14 Jul 2026 (actual)
- Results
- Not posted in the source record
Clinical summary
The research question as the sponsor registered it. This describes what the study plans to test, not what it found.
This study is a randomized, single-blind, sham-controlled crossover trial enrolling 30 schizophrenia patients, each receiving one active and one sham tACS session (7-day washout), targeting P3/P4 at individual alpha frequency (2mA, 30min) during a working memory task, with accuracy and reaction time as primary outcomes, alongside EEG and neurophysiological measures, to test the efficacy and mechanisms of individualized alpha-tACS on working memory.
Detailed description
This study is a randomized, single-blind, sham-controlled, crossover exploratory trial that plans to enroll 30 inpatients with schizophrenia, randomized 1:1 into two groups, with all participants receiving one active and one sham tACS session in a crossover manner separated by a 7-day washout. Stimulation targets the parietal P3/P4 sites at individual alpha frequency, with an intensity of 2 mA and a duration of 30 minutes per session, delivered concurrently with a working memory task (SIRP). Primary outcomes are SIRP accuracy and reaction time, with concurrent task-state EEG recording, along with assessments of clinical symptoms, cognitive function, and neurophysiological markers including ASSR, MMN, and P300. The study aims to explore the efficacy and underlying neural mechanisms of individualized alpha-tACS in improving working memory in schizophrenia.
Study design
- Primary purpose
- Treatment
- Allocation
- Randomised
- Intervention model
- Parallel groups
- Masking
- Single blind (participant)
- Number of arms
- 2
| Arm | Type | Receives |
|---|---|---|
| sham group | Sham comparator | Device: sham stimulationsham stimulation |
| active group | Experimental | Device: transcranial alternating current stimulationtranscranial alternating current stimulation |
Who may qualify
- Ages
- 18 to 50 years
- Sex
- All
- Healthy volunteers
- Not accepted
- Age groups
- Adult
Key inclusion criteria (5 listed)
- Aged 18-50 years, meeting the Diagnostic and Statistical Manual of Mental Disorders, Fifth Edition (DSM-5) diagnostic criteria for schizophrenia, confirmed by the Structured Clinical Interview for DSM-5 (SCID-5).
- Spatial span T-score <40 on the MATRICS Consensus Cognitive Battery (MCCB).
- Taking 1-2 antipsychotic medications, with stable dosage for at least 1 week prior to enrollment. No use of mood stabilizers, antidepressants, or excessive benzodiazepines (lorazepam equivalent >2 mg/day). The type and dosage of antipsychotic medications remain unchanged during the treatment period.
- Impaired functioning in daily activities.
- Willing to participate in this study and provide written informed consent.
Key exclusion criteria (6 listed)
- Previously diagnosed with or comorbid any other DSM-5 mental disorder besides schizophrenia.
- Presence of significant mood symptoms or substance use disorder (other than caffeine and/or tobacco).
- Presence of any contraindication to transcranial alternating current stimulation (tACS).
- Received other forms of electrical or magnetic stimulation therapy within 1 month prior to enrollment.
- History or current presence of any major physical illness, neurological disorder, or traumatic brain injury that may affect brain structure or function.
Eligibility is decided by the study team after screening; this overview does not establish that a patient qualifies. Full inclusion and exclusion criteria.
Interventions
| Intervention | Type | Arms |
|---|---|---|
| transcranial alternating current stimulationFor montage 1, active electrode at P3 (10-10 system), return electrodes at P1, P5, PO3, CP3. For montage 2, active electrode at P4, return electrodes at P2, P6, PO4, CP4. Conductive paste ensures impedance <10 kΩ. Individual alpha frequency is used, calculated before each session from mean EEG at P3/P4 during SIRP task. Stimulation intensity is 2 mA (peak-to-zero) via electric field modeling. Stimulation is delivered during SIRP task, 30 min total per session (including 15s ramp-up/down), with continuous sine wave output. | Device | active group |
| sham stimulationSham stimulation provides only a 15-second ramp-up and ramp-down current at the beginning and end of each session to mimic the initial tingling or itching sensation on the scalp produced by real stimulation, but delivers no effective stimulation current during the main phase of the task period. | Device | sham group |
Primary outcome
Working Memory Accuracy
Time frame: Day 1 (baseline, prior to first intervention); within 15 minutes after Session 1; Day 9 (prior to second intervention, after 7-day washout); within 15 minutes after Session 2.
Assessment of task accuracy on the Sternberg Item Recognition Paradigm (SIRP). Participants are required to judge whether a probe stimulus belongs to a previously memorized set, with memory set sizes of 1 and 5. The outcome is measured as the percentage of correct responses (0-100%) across all trials, with higher scores indicating better working memory performance.
Working Memory Reaction Time
Time frame: Day 1 (baseline, prior to first intervention); within 15 minutes after Session 1; Day 9 (prior to second intervention, after 7-day washout); within 15 minutes after Session 2.
Assessment of response speed on the Sternberg Item Recognition Paradigm (SIRP). Participants are required to judge whether a probe stimulus belongs to a previously memorized set, with memory set sizes of 1 and 5. The outcome is measured as the mean response latency for correct responses only, calculated from stimulus onset to the participant's button press, with shorter times indicating faster processing speed.
10 secondary outcomes
Changes in MCCB Performance
Time frame: Baseline, on the day after each of the two interventions
Changes in Positive and Negative Symptom Scale (PANSS) Scores
Time frame: Before and one week after each of the two interventions.
Changes in Scale for the Assessment of Negative Symptoms (SANS) Scores
Time frame: Before and one week after each of the two interventions.
Changes in Calgary Depression Scale for Schizophrenia (CDSS) Scores
Time frame: Before and one week after each of the two interventions.
Changes in Brain Function
Time frame: Baseline, on the day after each of the two interventions.
Changes in Neuroelectrophysiological Signals
Time frame: Baseline, 30 minutes after each of the two interventions.
Changes in 40Hz Auditory Steady-State Response (40Hz-ASSR)
Time frame: Baseline, 30 minutes after each of the two interventions.
Changes in Mismatch Negativity (MMN)
Time frame: Baseline, 30 minutes after each of the two interventions.
Changes in P300 Event-Related Potential
Time frame: Baseline, 30 minutes after each of the two interventions.
Hallucination and Delusion Visual Analog Scale (HD-VAS) Score
Time frame: Within 15 minutes after completion of Session 1; within 15 minutes after completion of Session 2.
Results and safety
This study is still under way. Results are not available in the source record yet.
Research links
- Official record on ClinicalTrials.govLast updated by the sponsor 14 Jul 2026.
- Individual participant dataSharing planned: No
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Referral and contact
AzTrials does not enrol participants or take referrals. Contact the study team or a site listed below; they decide who can take part.
1 site in 1 country: see every site and its status.
Questions about this trial
What is this clinical trial studying?
A study testing transcranial alternating current stimulation in people with Schizophrenia and Working Memory, run by Central South University at 1 site in China.
The full registered description is in the About this study section and the official record.
Who may be eligible to take part?
The sponsor lists 5 inclusion and 6 exclusion criteria. Eligibility is decided by the study team after screening, so read the full criteria and contact a listed site.
Is this clinical trial currently recruiting?
The record says: looking for participants now, as of the sponsor's last update on 14 Jul 2026. Status can change between updates, so confirm with the study contact before making plans.
Where is the study taking place?
The record lists 1 site in China. Whether a site is taking part right now should be confirmed with that site. See every site.
What are the possible benefits and risks?
They depend on the study and the treatment, and no study can promise a benefit. Some participants in this study may receive a placebo. The study team explains the known risks during informed consent, before anyone joins; the record itself does not list them.
Are results available for this study?
This study is still under way. Results are not available in the source record yet.
How can a doctor refer a patient or contact the research team?
Contact Renrong Wu (15874179855, wurenrong@csu.edu.cn), or a site near the patient. AzTrials does not enrol participants or take referrals.
What does the primary outcome measure?
Working Memory Accuracy (time frame: Day 1 (baseline, prior to first intervention); within 15 minutes after Session 1; Day 9 (prior to second intervention, after 7-day washout); within 15 minutes after Session 2.). The study lists 2 primary outcomes in all. It is what the study was designed to measure, not a finding.
Where can I read the original study information?
Does a listing mean the treatment is approved or proven to work?
No. A listing means the study is registered. It does not show that the treatment is safe, works, or is approved by a regulator.
How often is this information updated?
AzTrials copies changed records from ClinicalTrials.gov every night and reloads the whole registry every week. The sponsor last updated this record on 14 Jul 2026; AzTrials last refreshed its copy on 28 Oct 2026.