Updated June 2026 · ClinicalTrials.gov

RECRUITINGPhase 3INTERVENTIONAL

Metformin Treatment on Cognitive Impairment of Schizophrenia

Q: Who can participate in NCT05838573?

Eligibility for this trial depends on the specific inclusion and exclusion criteria set by the sponsor. The plain-English summary above translates the most important criteria into accessible language; the official clinical text is preserved in the collapsible section underneath. Whether you fit any specific trial is a medical decision your doctor needs to confirm — bring the trial information to your treating physician for a full review against your medical history.

Q: How do I contact the trial site for NCT05838573?

Contact information registered with ClinicalTrials.gov is shown in the sidebar of this page. Before reaching out, confirm with your treating physician that this trial is appropriate for your situation. The trial site will then walk you through the screening process to determine final eligibility.

Q: Is participating in a clinical trial safe?

Clinical trials in the United States are regulated by the FDA and overseen by Institutional Review Boards (IRBs) that review the protocol for safety. Risk varies by trial — Phase 1 studies test new treatments in humans for the first time, while Phase 3 trials use treatments that have already passed earlier safety screening. The informed consent document for any specific trial details the known risks and what to expect. Discuss those risks with your physician before deciding whether to participate.

Q: Where can I verify the data on this page?

Every detail on this page comes directly from the ClinicalTrials.gov API. Click "View on ClinicalTrials.gov" in the sidebar to see the official, unmodified record. The federal record is always authoritative; this page is a structured presentation with a plain-English eligibility translation. For background on how clinical trials are regulated, see the FDA drug approval process documentation.

The Effect of Metformin Treatment on Cognitive Impairment in Individuals With Schizophrenia: A 24-week Multicentre Randomised Controlled Trial

Metformin Treatment on Cognitive Impairment of Schizophrenia (NCT05838573) is a Phase 3 interventional studying Schizophrenia, sponsored by Central South University. RECRUITING as of the most recent ClinicalTrials.gov update. Talk to your doctor before contacting the trial site.

About This Trial

In this study, the investigators will investigate the effect and the underlying mechanism of metformin treatment on cognitive impairment in individuals with schizophrenia. The study will recruit 120 individuals with schizophrenia at 4 sites, who will be randomized to metformin or placebo group for 24-week treatment. Clinical assessments will be done at screen/baseline, 12th week and 24th week. Participants who don't meet any of the diagnostic criteria for metabolic syndrome will only accept baseline evaluations. The specific aims are to compare healthy volunteers versus schizophrenic participants on:1) cognition; 2) MRI features, and to compare metformin group versus placebo group of 24-week treatment cohort on: 1) cognition; 2) clinical core symptoms; 3) MRI features. Biological samples also will be collected and stored to explore related mechanisms.

What Stage of Research Is This?

Phase 3 trials confirm efficacy and safety in large patient groups (often 300–3,000+) and form the evidence base for an FDA approval submission. For Schizophrenia, Phase 3 studies typically randomize participants between the investigational treatment and either a placebo or current standard of care. A successful Phase 3 result is the threshold most treatments need to clear before regulatory approval.

This trial is currently recruiting participants. The sponsor has registered the study with ClinicalTrials.gov as actively enrolling, which means new applicants who meet the eligibility criteria can be considered for screening. Trial status can change between updates — confirm current recruiting status with the study contact before traveling for a screening visit.

Target enrollment of 120 participants puts this in the typical range for a Phase 2-style efficacy study or a moderate Phase 3 trial in a focused Schizophrenia subpopulation. At this scale, the study has enough statistical power to detect a clear treatment effect but is not the largest cohort in the field.

Who May Be Eligible (Plain English)

Who May Qualify: 1. Male and female aged 18 to 50 years, who meet the Diagnostic and Statistical Manual (DSM-5) diagnostic criteria for schizophrenia. 2. Duration of illness less than 15 years with current symptoms in a stable condition. 3. Participants must be receiving stable treatment with standard-of-care medications, with a maximum allowance of two antipsychotic medications. If additional anticholinergic agents are required for the management of extrapyramidal symptoms, they should be prescribed at low dosages. 4. Have great compliance with medication and follow-up. 5. Meet one of the diagnostic criteria for metabolic syndrome: 1)abdominal obesity (i.e. central obesity): waist circumference for male≥90 cm, for female ≥85 cm; 2)fasting blood glucose ≥110 mg/dl (6.1 mmol/l) and/or plasma glucose ≥140 mg/dl (7.8 mmol/l) after glucose load; 3)at fasting state, triglyceride ≥1.7 mmol/l; 4)at fasting state, HDL-C \<1.04 mmol/L. 6. Signed the study consent for participation. Who Should NOT Join This Trial: 1. Having a history of substance dependence or abuse or whose symptoms are caused by other diagnosable mental disorders. 2. Having a history of traumatic brain injury, seizures or other known neurological or organic diseases of the central nervous system. 3. Taking antidepressants, stimulants, mood stabilizers or accepts electricity shock treatment. 4. Having current suicidal or homicidal thoughts or any safety concern by research staff that cannot be managed in an inpatient setting. 5. Taking dementia related drugs, minocycline, and other drugs that could affect cognitive function. 6. The routine blood tests showing significant abnormal renal, liver function or other somatic disease. 7. Pregnant or lactating women. For schizophrenic participants who don't meet any of the diagnostic criteria for metabolic syndrome will only accept baseline evaluations. Always talk to your doctor about whether this trial is right for you.

These are translations of the protocol\'s inclusion and exclusion criteria, simplified for patients and caregivers. The original clinical text appears below. Eligibility is ultimately confirmed by the trial site\'s screening process — this summary is a starting point for a conversation with your doctor, not a final determination.

Original Eligibility Criteria

View original clinical language

Inclusion Criteria: 1. Male and female aged 18 to 50 years, who meet the Diagnostic and Statistical Manual (DSM-5) diagnostic criteria for schizophrenia. 2. Duration of illness less than 15 years with current symptoms in a stable condition. 3. Participants must be receiving stable treatment with standard-of-care medications, with a maximum allowance of two antipsychotic medications. If additional anticholinergic agents are required for the management of extrapyramidal symptoms, they should be prescribed at low dosages. 4. Have great compliance with medication and follow-up. 5. Meet one of the diagnostic criteria for metabolic syndrome: 1)abdominal obesity (i.e. central obesity): waist circumference for male≥90 cm, for female ≥85 cm; 2)fasting blood glucose ≥110 mg/dl (6.1 mmol/l) and/or plasma glucose ≥140 mg/dl (7.8 mmol/l) after glucose load; 3)at fasting state, triglyceride ≥1.7 mmol/l; 4)at fasting state, HDL-C \<1.04 mmol/L. 6. Signed the study consent for participation. Exclusion Criteria: 1. Having a history of substance dependence or abuse or whose symptoms are caused by other diagnosable mental disorders. 2. Having a history of traumatic brain injury, seizures or other known neurological or organic diseases of the central nervous system. 3. Taking antidepressants, stimulants, mood stabilizers or accepts electricity shock treatment. 4. Having current suicidal or homicidal thoughts or any safety concern by research staff that cannot be managed in an inpatient setting. 5. Taking dementia related drugs, minocycline, and other drugs that could affect cognitive function. 6. The routine blood tests showing significant abnormal renal, liver function or other somatic disease. 7. Pregnant or lactating women. For schizophrenic participants who don't meet any of the diagnostic criteria for metabolic syndrome will only accept baseline evaluations.

Treatments Being Tested

DRUG

Metformin treatment

Participants assigned to the metformin group will receive 500mg metformin three times daily (tid) for 24 weeks. The initial dose will be 500 mg orally in the evening for the first two days, followed by an increase to 500mg twice a day for the subsequent two days. By day 5, the dosage will be further increased to 500mg tid. The highest tolerated dosage will be maintained for participants who could not tolerate the maximum dosage.

DRUG

Placebo treatment

Parallel-dose adjustments will be made for the placebo group to maintain consistency in dosing between the two groups.

OTHER

Baseline assessments

Schizophrenic participants who don't meet any of the diagnostic criteria for metabolic syndrome will only accept baseline evaluations.

OTHER

Volunteer assessments

Apart from psychiatry scales(Hamilton Depression Scale, Young Mania Rating Scale and Self-reporting Inventory-90), other assessments for the healthy subjects are the same as the baseline for sczhiophrenic participants.

Locations (4)

Trial sites listed on ClinicalTrials.gov for this study. Site activation status can vary — confirm with the specific site before traveling for a screening visit.

Mental Health Institute of Second Xiangya Hospital,CSU

Changsha, Hunan, China

The Third Peoples's Hospital of Jiangyin

Jiangyin, Jiangsu, China

Shandong Mental Health Center

Jinan, Shandong, China

The Second People's Hospital of Dali Bai Autonomous Prefecture

Dali, Yunnan, China

How to Talk to Your Doctor About This Trial

Bring the printable summary of this trial — including the NCT ID (NCT05838573), the sponsor (Central South University), and the key eligibility criteria — to your next appointment. Your doctor can review the inclusion and exclusion criteria against your medical history, lab values, and current treatments to assess whether you are likely to qualify. They can also help you weigh whether trial participation makes sense alongside your existing care plan.

Useful questions to walk through together: What does the trial protocol require beyond standard care? How long is the active treatment phase, and how long is follow-up? Are there study visits at sites I can reach? Who pays for the trial-specific procedures, and who pays for standard-of-care portions? See our 25 questions to ask about clinical trials guide for a more complete checklist.

Authoritative Sources

The official record for this trial lives on ClinicalTrials.gov — the federal registry maintained by the National Library of Medicine at NIH. For background on how this trial fits into the FDA approval pathway, see the FDA drug approval process. For oncology-specific guidance for patients considering trials, the National Cancer Institute publishes patient-oriented overviews. International trial registries are aggregated by the WHO ICTRP.

Frequently Asked Questions

What is the NCT05838573 clinical trial studying?

In this study, the investigators will investigate the effect and the underlying mechanism of metformin treatment on cognitive impairment in individuals with schizophrenia. The study will recruit 120 individuals with schizophrenia at 4 sites, who will be randomized to metformin or placebo group for 24-week treatment. Clinical assessments will be done at screen/baseline, 12th week and 24th week. Participants who don't meet any of the diagnostic criteria for metabolic syndrome will only accept baseline evaluations. The specific aims are to compare healthy volunteers versus schizophrenic participa… The full protocol is registered on ClinicalTrials.gov and includes the primary outcome measures, eligibility criteria, and study endpoints.

Who can participate in NCT05838573?

Eligibility for this trial depends on the specific inclusion and exclusion criteria set by the sponsor. The plain-English summary above translates the most important criteria into accessible language; the official clinical text is preserved in the collapsible section underneath. Whether you fit any specific trial is a medical decision your doctor needs to confirm — bring the trial information to your treating physician for a full review against your medical history.

How do I contact the trial site for NCT05838573?

Contact information registered with ClinicalTrials.gov is shown in the sidebar of this page. Before reaching out, confirm with your treating physician that this trial is appropriate for your situation. The trial site will then walk you through the screening process to determine final eligibility.

Is participating in a clinical trial safe?

Clinical trials in the United States are regulated by the FDA and overseen by Institutional Review Boards (IRBs) that review the protocol for safety. Risk varies by trial — Phase 1 studies test new treatments in humans for the first time, while Phase 3 trials use treatments that have already passed earlier safety screening. The informed consent document for any specific trial details the known risks and what to expect. Discuss those risks with your physician before deciding whether to participate.

Where can I verify the data on this page?

Every detail on this page comes directly from the ClinicalTrials.gov API. Click "View on ClinicalTrials.gov" in the sidebar to see the official, unmodified record. The federal record is always authoritative; this page is a structured presentation with a plain-English eligibility translation. For background on how clinical trials are regulated, see the FDA drug approval process documentation.

How This Page Is Built

Every field on this page is pulled directly from the ClinicalTrials.gov API v2 — no estimates, no proxies. The plain-English eligibility translation is generated from the original protocol text and reviewed for fidelity to the underlying clinical criteria. The original clinical text remains visible in the collapsible section above so users and clinicians can verify the translation. Read the full methodology for the data pipeline and known limitations.

Source: ClinicalTrials.gov API v2 record for NCT05838573. Maintained by the National Library of Medicine at NIH. Public domain. Cite as: "TrialFinderData. NCT05838573. Data: ClinicalTrials.gov."

Medical disclaimer: This page is informational, not medical advice. Talk to your doctor about whether a clinical trial is right for you.

Last updated 2026-06-07 · Data from ClinicalTrials.gov.