Metformin's effect on cognitive impairment in schizophrenia

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

Phase 3 Interventional Central South University · NCT05838573

This study tests whether metformin can help improve thinking skills in people with schizophrenia compared to a placebo over 24 weeks.

Quick facts

PhasePhase 3
Study typeInterventional
Enrollment120 (estimated)
Ages18 Years to 50 Years
SexAll
SponsorCentral South University Academic / other
Locations4 sites (Changsha, Hunan and 3 other locations)
Trial IDNCT05838573 on ClinicalTrials.gov

What this trial studies

This study investigates the impact of metformin treatment on cognitive impairment in individuals diagnosed with schizophrenia. A total of 120 participants will be randomized into either a metformin or placebo group for a 24-week treatment period. Assessments will include clinical evaluations, MRI scans, and cognitive function tests at baseline, 12 weeks, and 24 weeks. The study aims to compare cognitive and clinical outcomes between the two groups and explore underlying mechanisms through biological sample collection.

Who should consider this trial

Good fit: Ideal candidates are males and females aged 18 to 50 with a diagnosis of schizophrenia and evidence of metabolic syndrome.

Not a fit: Patients who do not meet the diagnostic criteria for metabolic syndrome or have a duration of illness exceeding 15 years may not benefit from this study.

Why it matters

Potential benefit: If successful, this treatment could improve cognitive function in patients with schizophrenia, enhancing their overall quality of life.

How similar studies have performed: While the use of metformin in schizophrenia is being explored, this specific approach focusing on cognitive impairment is relatively novel and has not been extensively tested in prior studies.

Eligibility criteria

Show full inclusion / exclusion criteria
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.

Where this trial is running

Changsha, Hunan and 3 other locations

Study contacts

How to participate

  1. Review the eligibility criteria above with your treating physician.
  2. Visit the official trial page on ClinicalTrials.gov for the most current contact information and recruitment status.
  3. Contact the listed study coordinator or principal investigator to request pre-screening. Pre-screening is free and never obligates you to enroll.
Conditions SchizophreniaCognitive impairmentMetforminClinical trial
Last reviewed 2026-06-15 by the Find a Trial editorial team. Information on this page is for educational purposes and is not medical advice. Always consult qualified healthcare professionals about clinical trial participation.