PQQ for Cognitive and Negative Symptoms
For patients and families
In plain language
An automatic summary of structured registry data. It is an orientation aid, not a substitute for the official protocol or a physician assessment.
- What is being studied
- The protocol lists: Pyrroloquinoline quinone (PQQ), placebo (dietary fiber).
- Who it may be relevant to
- Registry conditions: Schizophrenia, Cognitive Symptoms, Negative Symptoms. Basic parameters: 18 years — 50 years · All.
- What needs checking
- Age, condition and sex are only basic indicators. Prior treatment, laboratory values and other mandatory requirements appear in the eligibility criteria below.
- Where it takes place
- Center list to be confirmed — check the primary protocol.
- Next step
- Save the trial, show it to the treating physician, and confirm current recruitment with the study center. Costs, documents and travel →
Unsure about the terms? Read our patient guide →
Official title
The Efficacy and Safety of Pyrroloquinoline Quinone add-on Treatment for Negative and Cognitive Symptoms in Chronic Schizophrenia
Overview
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.
Interventions
- Dietary supplement Pyrroloquinoline quinone (PQQ)
Patients with chronic schizophrenia in experimental group will take 20 mg of PQQ orally every day for a total of 12 weeks. - Dietary supplement placebo (dietary fiber)
Patients with chronic schizophrenia in control group will a capsule of placebo orally every day for a total of 12 weeks.
Primary outcome measures
- cognitive symptoms [Time frame: From enrollment to the end of 12 weeks]
- negative symptoms [Time frame: From enrollment to the end of 12 weeks]
Secondary outcome measures (3)
- congtive/negative symptoms [Time frame: From enrollment to the end of 20 weeks]
- Malondialdehyde, Mitochondrial DNA, and Glutathione Peroxidase [Time frame: From enrollment to the end of 12 weeks and 20 weeks]
- Connectivity strength of target neural circuits [Time frame: From enrollment to the end of 12 weeks and 20 weeks]
Eligibility criteria
Inclusion criteria
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.
Exclusion criteria
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).
Additional exclusion criteria for participants undergoing fMRI scanning:
Participants are required to complete a comprehensive safety questionnaire addressing potential risks associated with exposure to a 3-Tesla magnetic field and the MRI environment. MRI-specific exclusion criteria include: the presence of MRI-incompatible implants (e.g., cochlear implants, insulin pumps, pacemakers, or other metallic implants); a history of possible intraocular metallic foreign bodies due to manual labor without appropriate eye protection; tattoos containing red pigments; claustrophobia; or unwillingness to be informed of any incidental structural brain abnormalities detected during the scan.
Criteria are shown verbatim from the registry (in English). Final eligibility is always assessed by the study center.
Healthy volunteers: No
Study design
- Allocation
- Randomized
- Model
- Parallel assignment
- Masking
- Quadruple blind
- Primary purpose
- Treatment
Study locations
Center list to be confirmed — check the primary protocol.
Publications
- 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
- 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
- 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
- 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
Identifiers
NCT: NCT07393464 · TJPQQ2026