ArticlePloS one2014
Elevated levels of plasma phenylalanine in schizophrenia: a guanosine triphosphate cyclohydrolase-1 metabolic pathway abnormality?
Article in PloS one, 2014. The graph could read no effect estimate from its abstract, so it casts no vote on the map. Cited by 15 papers.
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Who cites it
15 citing papers in PubMed, 29 citations in OpenAlex.
- Metabolic Mechanisms in Electroconvulsive Therapy for Schizophrenia: Role, Potential and Future Directions.International journal of molecular sciences · 2026Review
- Targeted metabolomics study on peripheral blood neurotransmitters in early-onset schizophrenia.Journal of translational medicine · 2025Article
- Immunometabolic and brain structural alterations mediate increased risk of brain diseases in rheumatoid arthritis patients.Translational psychiatry · 2025Article
- Article
- Identification of biomarkers related to propionate metabolism in schizophrenia.Frontiers in psychiatry · 2025Article
- Identification of potential biomarkers and pathways involved in high-altitude pulmonary edema using GC-MS and LC-MS metabolomic methods.Scientific reports · 2024Article
- Behavioral and Psychiatric Disorders in Syndromic Autism.Brain sciences · 2024Review
- Article
- Protective effects ofFrontiers in pharmacology · 2023Article
- Variational autoencoders learn transferrable representations of metabolomics data.Communications biology · 2022Article
- Review
- Psychiatric and Cognitive Aspects of Phenylketonuria: The Limitations of Diet and Promise of New Treatments.Frontiers in psychiatry · 2019Review
- Moderation of the relationship between Toxoplasma gondii seropositivity and trait impulsivity in younger men by the phenylalanine-tyrosine ratio.Psychiatry research · 2018Article
- Reciprocal moderation byPteridines · 2016Article
- Blood Levels of Monoamine Precursors and Smoking in Patients with Schizophrenia.Frontiers in public health · 2016Article
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Authors and funding
16 authors at 6 institutions in 3 countries.
Funding
No grant is acknowledged in the PubMed record.
Abstract
backgroundPhenylalanine and tyrosine are precursor amino acids required for the synthesis of dopamine, the main neurotransmitter implicated in the neurobiology of schizophrenia. Inflammation, increasingly implicated in schizophrenia, can impair the function of the enzyme Phenylalanine hydroxylase (PAH; which catalyzes the conversion of phenylalanine to tyrosine) and thus lead to elevated phenylalanine levels and reduced tyrosine levels. This study aimed to compare phenylalanine, tyrosine, and their ratio (a proxy for PAH function) in a relatively large sample of schizophrenia patients and healthy controls.
methodsWe measured non-fasting plasma phenylalanine and tyrosine in 950 schizophrenia patients and 1000 healthy controls. We carried out multivariate analyses to compare log transformed phenylalanine, tyrosine, and phenylalanine:tyrosine ratio between patients and controls.
resultsCompared to controls, schizophrenia patients had higher phenylalanine (p<0.0001) and phenylalanine: tyrosine ratio (p<0.0001) but tyrosine did not differ between the two groups (p = 0.596).
conclusionsElevated phenylalanine and phenylalanine:tyrosine ratio in the blood of schizophrenia patients have to be replicated in longitudinal studies. The results may relate to an abnormal PAH function in schizophrenia that could become a target for novel preventative and interventional approaches.
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