Schizophrenia is a common, long-term mental illness. It causes problems with thoughts, feelings, and behavior, including positive symptoms (hallucinations, delusions), negative symptoms (lack of emotion, motivation), and cognitive impairment (trouble with thinking, memory, and attention). While antipsychotic drugs effectively treat positive symptoms, they don't help much with cognitive impairment.This study will examine how the tryptophan-kynurenine pathway in the brain contributes to cognitive problems in people having their first episode of schizophrenia and treated with a single antipsychotic. Our goal is to create models for early detection of cognitive impairment in schizophrenia and find potential targets for new treatments to improve thinking and memory.
Eligibility
Sex
ALL
Min age
18 Years
Max age
55 Years
Healthy volunteers
Accepted
Inclusion Criteria:
* Healthy volunteers matched to the patient group on sex, age, and education level;
* Ethnic Han Chinese;
* Able and willing to provide written informed consent.
Exclusion Criteria:
* Significant comorbid medical or neurological conditions;
* Any DSM-5-defined psychiatric disorder;
* Family history of psychiatric illness spanning three or more generations;
* Current use of psychoactive medications;
* Refusal to provide informed consent/participate.
Primary outcome measure(s)
TRP-KYN pathway candidate plasma metabolite levels — Baseline, week8 Plasma levels of tryptophan-kynurenine (TRP-KYN) pathway candidate metabolites, including kynurenine, kynurenic acid, kynurenic quinolinic acid, quinolinic acid, tryptophan, indole-3-acetic acid, and indole-3-propionic acid, were quantified using liquid chromatography-tandem mass spectrometry (LC-MS/MS). Sample information was registered in MetLIMS software, with designated positions for samples of interest, blanks, standards, and quality control samples. Samples were added to corresponding wells in a 96-well plate provided in the kit. Subsequently, derivatization was performed by adding a 5% phenylisothiocyanate solution. Finally, target analytes were extracted with an organic solvent and diluted. The pre-processed sample extracts underwent High-Performance Liquid Chromatography-Mass Spectrometry detection. Each sample was analyzed in two parts: the first involved signal acquisition in flow injection analysis mode, and the second in liquid chromatography-mass spectrometry mode.
Cognitive Function — Baseline, week8 All participants underwent cognitive function assessment based on the MATRICS Consensus Cognitive Battery (MCCB). The MCCB is a standardized instrument for assessing cognitive function in schizophrenia. It comprises nine subtests primarily evaluating seven cognitive domains: processing speed, attention/alertness, working memory, verbal learning, visual memory, reasoning and problem-solving, and social cognition. The MCCB scoring procedure generates standardised T-scores that are corrected for age, gender, and educational level. Higher T-scores indicate better cognitive function.
Candidate gene mRNA expression levels — Baseline, week8 Whole blood was collected in BD PAXgene® Blood RNA tubes (2.5 mL from antecubital veins) and gently inverted to mix. Samples were incubated vertically at room temperature for 2 hours, then stored at -20°C overnight before transfer to -80°C for RNA extraction. Extracted RNA was reverse transcribed to synthesize cDNA. Gene expression levels of TDO, IDO, KMO, KAT-II, KYNU, and 3HAO were determined by RT-qPCR with gel electrophoresis for product validation and densitometric scanning using a gel imaging system.
This page summarises publicly available registry data for informational purposes — not medical advice. Eligibility is determined by each study team; patients should discuss participation with their clinician.
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