PQQ for Cognitive and Negative Symptoms

NCT07393464 | Not Yet Recruiting DMC

• 1 other identifier: TJPQQ2026
• Study Type: interventional
• Target: 70
• Locations: 0 countries
• Sites: N/A

Brief Summary

Schizophrenia is a complex mental disorder characterized by a range of symptoms, including negative symptoms and cognitive impairments. Recent research has indicated the potential benefits of targeting mitochondrial dysfunction, oxidative stress, and inflammatory responses in alleviating symptoms of schizophrenia. However, the results remain inconsistent across various studies. This study aims to evaluate the efficacy of Pyrroloquinoline quinone (PQQ) in reducing negative symptoms and improving cognitive function in patients with chronic schizophrenia. The investigation will focus on changes in severity scores from baseline to endpoint, as well as during an eight-week follow-up period. A double-blind, randomized controlled trial will be conducted involving participants diagnosed with chronic schizophrenia. Participants will be randomly assigned to receive either PQQ or a matched placebo. Data will be collected through questionnaires and neuroimaging techniques, including resting-state scans and multimodal tasks to assess functional connectivity and activation in target brain regions. Statistical analyses will include descriptive statistics, voxel-by-voxel multiple regression, and linear mixed models to account for repeated measurements. Additionally, potential moderating effects of demographic factors such as age and gender will be examined using ANCOVAs. The study will also monitor adverse events and ensure participant safety through a rigorous reporting and unblinding procedure. It is hope to provide insights into the therapeutic potential of PQQ in managing schizophrenia symptoms, contributing to the development of more effective treatment strategies for this challenging condition.

Conditions

Schizophrenia; Cognitive Symptoms; Negative Symptoms

Keywords

cognitive symptom; negative symptom; schizophrenia; Pyrroloquinoline Quinone; MCCB

Outcome Measures

Primary Outcomes (2)

• cognitive symptoms

  the changes in scores of MCCB between the baseline and the first post-treatment measurement.

  From enrollment to the end of 12 weeks

• negative symptoms

  the changes in scores of PANSS negative subscale between the baseline and the first post-treatment measurement.

  From enrollment to the end of 12 weeks

Secondary Outcomes (3)

• congtive/negative symptoms

  From enrollment to the end of 20 weeks

• Malondialdehyde, Mitochondrial DNA, and Glutathione Peroxidase

  From enrollment to the end of 12 weeks and 20 weeks

• Connectivity strength of target neural circuits

  From enrollment to the end of 12 weeks and 20 weeks

Study Arms (2)

PQQ group

EXPERIMENTAL

Dietary Supplement: Pyrroloquinoline quinone (PQQ)

Control group

PLACEBO COMPARATOR

Dietary Supplement: placebo (dietary fiber)

Interventions

Pyrroloquinoline quinone (PQQ) DIETARY_SUPPLEMENT

Patients with chronic schizophrenia in experimental group will take 20 mg of PQQ orally every day for a total of 12 weeks.

PQQ group

placebo (dietary fiber) DIETARY_SUPPLEMENT

Patients with chronic schizophrenia in control group will a capsule of placebo orally every day for a total of 12 weeks.

Control group

Eligibility Criteria

• Age: 18 Years - 50 Years
• Sex: all
• Healthy Volunteers: No
• Age Groups: Adult (18-64)

You may qualify if:

• Eligible male and female patients aged 18 to 50 years, diagnosed with schizophrenia according to the criteria outlined in the Diagnostic and Statistical Manual of Mental Disorders, Fifth Edition, Text Revision (DSM-5), will be included in the study. Participants are required to meet the following criteria: a Positive and Negative Syndrome Scale (PANSS) total scores of ≥ 60 (indicating an active phase of the illness), a PANSS negative subscale scores of ≥ 20, and a duration of illness of at least 2 years (indicating chronic schizophrenia). Additionally, participants must have been on a stable dose of antipsychotic medication for a minimum of 6 weeks prior to enrollment, and the use of antioxidants or anti-inflammatory medications is prohibited within 2 weeks preceding enrollment.

You may not qualify if:

• Patients with comorbid psychiatric disorders as defined by the DSM-5, such as substance abuse or dependence (excluding nicotine), or intellectual disability (IQ \< 70); those with significant depressive symptoms, defined as a score ≥14 on the 17-item Hamilton Depression Rating Scale (HAMD-17) or ≥ 4 on the depression item of PANSS; individuals with severe medical or neurological conditions, or those unable to communicate effectively; patients with a known allergy to PQQ disodium salt, or who are pregnant, breastfeeding, or have severe hepatic or renal impairment; women of childbearing potential who are not using reliable contraception; patients who have received modified electroconvulsive therapy (MECT) or other physical treatments within six months prior to enrollment; and those currently receiving treatments that cannot be discontinued, including antidepressants, mood stabilizers, antihistamines, or combination therapy with two or more antipsychotics (except for low-dose aripiprazole, ≤ 5 mg/day, used solely for prolactin reduction).

Sponsors & Collaborators

• Tianjin Anding Hospital: lead

Related Publications (4)

• Tamakoshi M, Suzuki T, Nishihara E, Nakamura S, Ikemoto K. Pyrroloquinoline quinone disodium salt improves brain function in both younger and older adults. Food Funct. 2023 Mar 6;14(5):2496-2501. doi: 10.1039/d2fo01515c.

  PMID: 36807425 BACKGROUND

• Nunome K, Miyazaki S, Nakano M, Iguchi-Ariga S, Ariga H. Pyrroloquinoline quinone prevents oxidative stress-induced neuronal death probably through changes in oxidative status of DJ-1. Biol Pharm Bull. 2008 Jul;31(7):1321-6. doi: 10.1248/bpb.31.1321.

  PMID: 18591768 BACKGROUND

• Zhang P, Xu Y, Li L, Jiang Q, Wang M, Jin L. In vitro protective effects of pyrroloquinoline quinone on methylmercury-induced neurotoxicity. Environ Toxicol Pharmacol. 2009 Jan;27(1):103-10. doi: 10.1016/j.etap.2008.08.010. Epub 2008 Sep 7.

  PMID: 21783927 BACKGROUND

• Xiao L, Wang M, Li J, Wang H, Pu N, Bo X, Chen F, Zhou Y, Cheng Q. Pyrroloquinoline Quinone Preconditioning Alleviates Ischemic Cerebral Injury Through Antioxidant and Anti-Inflammatory Mechanisms. J Neuroimmune Pharmacol. 2025 Jul 23;20(1):75. doi: 10.1007/s11481-025-10234-1.

  PMID: 40696055 BACKGROUND

MeSH Terms

Conditions

Schizophrenia; Neurobehavioral Manifestations

Interventions

PQQ Cofactor; Dietary Fiber

Condition Hierarchy (Ancestors)

Schizophrenia Spectrum and Other Psychotic Disorders; Mental Disorders; Neurologic Manifestations; Nervous System Diseases; Signs and Symptoms; Pathological Conditions, Signs and Symptoms

Intervention Hierarchy (Ancestors)

Quinolones; Quinolines; Heterocyclic Compounds, 2-Ring; Heterocyclic Compounds, Fused-Ring; Heterocyclic Compounds; Coenzymes; Enzymes and Coenzymes; Dietary Carbohydrates; Carbohydrates; Food; Diet, Food, and Nutrition; Physiological Phenomena; Food and Beverages

Central Study Contacts

Daxiang Medical Ethics Committee of Tianjin Anding Hospital

CONTACT

0086-22-88188631; tjadllwyh@126.com

Study Design

• Study Type: interventional
• Phase: not applicable
• Allocation: RANDOMIZED
• Masking: QUADRUPLE
• Who Masked: PARTICIPANT, CARE PROVIDER, INVESTIGATOR, OUTCOMES ASSESSOR
• Masking Details: Participants will be randomized to receive either PQQ or a matched placebo in a double-blind, randomized controlled design. Treatment allocation will remain concealed from investigators, clinicians, and statisticians until the completion of data analysis. To ensure blinding, the placebo is matched to PQQ in appearance, odor, and color, and both are dispensed in identically sealed bottles. Each bottle is labeled as trial medication and assigned a random code (1-70) by the trial pharmacist, who maintains exclusive access to the randomization list stored securely until study completion. An independent individual, not involved in any aspect of the trial, generates the random allocation sequence based on the sequential enrollment of participants. Participants are assigned to either the intervention or control group according to this randomization protocol, using a table of random numbers. Participants are interviewed individually to prevent communication about treatment experiences. Medicat
• Purpose: TREATMENT
• Intervention Model: PARALLEL
• Sponsor Type: OTHER
• Responsible Party: PRINCIPAL INVESTIGATOR
• PI Title: PhD

Model Details: RCT

Study Record Dates

• First Submitted: January 31, 2026
• First Posted: February 6, 2026
• Study Start: February 15, 2026
• Primary Completion (Estimated): February 15, 2028
• Study Completion (Estimated): April 15, 2028
• Last Updated: February 10, 2026

Record last verified: 2026-02

Data Sharing

• IPD Sharing: Will share
• Shared Documents: STUDY PROTOCOL, SAP, ICF, CSR