SynthesisFrontiers in immunology2021
Tryptophan Catabolites in Bipolar Disorder: A Meta-Analysis.
Synthesis in Frontiers in immunology, 2021. The graph could read no effect estimate from its abstract, so it casts no vote on the map. Cited by 20 papers, 3 of them syntheses that pooled it.
What it found
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The trial behind it
Trials whose registry record cites this paper, or whose number appears in the abstract. A trial that started after this paper was published is citing it as background, not reporting it.
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Who cites it
20 citing papers in PubMed, 3 syntheses or guidelines pooled it, 34 citations in OpenAlex.
- Sex Differences in Tryptophan Metabolism: A Systematic Review Focused on Neuropsychiatric Disorders.International journal of molecular sciences · 2023Pooled it
- The relationship between immune and cognitive dysfunction in mood and psychotic disorder: a systematic review and a meta-analysis.Molecular psychiatry · 2022Pooled it
- BrainFrontiers in immunology · 2021Pooled it
- Metabolic pathways associated with cardiometabolic risk effects on cognition in middle-aged adults: the CARDIA study.Metabolomics : Official journal of the Metabolomic Society · 2026Article
- Dynamic immune dysregulation in severe mental illness: Exaggerated innate and attenuated adaptive immune responses following SARS-CoV-2 vaccination.Brain, behavior, & immunity - health · 2025Article
- Investigating seasonal metabolic variations in bipolar disorder: a targeted metabolomics study.BMC psychiatry · 2025Article
- The Microbiota-Gut-Brain Connection: A New Horizon in Neurological and Neuropsychiatric Disorders.CNS neuroscience & therapeutics · 2025Review
- Immune-neuroendocrine crosstalk in mood and psychotic disorders: A meta-analysis and systematic review.Brain, behavior, & immunity - health · 2025Review
- Alterations of Blood Plasma Metabolites, Including Kynurenine and Tryptophan, in Bipolar Disorder.Neuropsychiatric disease and treatment · 2025Article
- Comparing plasma levels and ratios of tryptophan, serotonin, kynurenine and quinolinic acid between patients with bipolar disorder and healthy controls: impact of depressive episode or post-traumatic stress disorder symptoms.Frontiers in psychiatry · 2025Article
- The role of the neuroinflammation and stressors in premenstrual syndrome/premenstrual dysphoric disorder: a review.Frontiers in endocrinology · 2025Review
- Investigating the Role of Serotonin Levels in Cognitive Impairments Associated with Long COVID-19.Chonnam medical journal · 2024Review
- Exploring the Relationship between Mood Disorders and Coexisting Health Conditions: The Focus on Nutraceuticals.Brain sciences · 2023Review
- Kynurenine pathway abnormalities are state-specific but not diagnosis-specific in schizophrenia and bipolar disorder.Brain, behavior, & immunity - health · 2023Article
- The tryptophan catabolite or kynurenine pathway in major depressive and bipolar disorder: A systematic review and meta-analysis.Brain, behavior, & immunity - health · 2022Review
- The association of kynurenine pathway metabolites with symptom severity and clinical features of bipolar disorder: An overview.European psychiatry : the journal of the Association of European Psychiatrists · 2022Review
- The Microbiota-Gut-Brain Axis in Psychiatric Disorders.International journal of molecular sciences · 2022Review
- The Role of Tryptophan Metabolites in Neuropsychiatric Disorders.International journal of molecular sciences · 2022Review
- Tracking TRYCAT: A Critical Appraisal of Kynurenine Pathway Quantifications in Blood.Frontiers in pharmacology · 2022Article
- The future of immunopsychiatry: Three milestones to clinical innovation.Brain, behavior, & immunity - health · 2021Article
Corrections and comments
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Authors and funding
6 authors at 1 institution in 2 countries.
Funding
No grant is acknowledged in the PubMed record.
Abstract
Objective: Tryptophan catabolites (TRYCATs) are implicated in the pathophysiology of mood disorders by mediating immune-inflammation and neurodegenerative processes. We performed a meta-analysis of TRYCAT levels in bipolar disorder (BD) patients compared to healthy controls. Methods: A systematic literature search in seven electronic databases (PubMed, Embase, Web of Science, Cochrane, Emcare, PsycINFO, Academic Search Premier) was conducted on TRYCAT levels in cerebrospinal fluid or peripheral blood according to the PRISMA statement. A minimum of three studies per TRYCAT was required for inclusion. Standardized mean differences (SMD) were computed using random effect models. Subgroup analyses were performed for BD patients in a different mood state (depressed, manic). The methodological quality of the studies was rated using the modified Newcastle-Ottawa Quality assessment Scale. Results: Twenty-one eligible studies were identified. Peripheral levels of tryptophan (SMD = -0.44; Conclusion: The TRYCAT pathway appears to be downregulated in BD patients. There is a need for more and high-quality studies of peripheral and central TRYCAT levels, preferably using longitudinal designs.
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Registered trials
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