Trial reportBMC medicine2011
L-lysine as adjunctive treatment in patients with schizophrenia: a single-blinded, randomized, cross-over pilot study.
Trial report in BMC medicine, 2011. The graph could read no effect estimate from its abstract, so it casts no vote on the map. Cited by 10 papers.
What it found
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The abstract states no effect estimate the extractor could read, or names no intervention and outcome on the map, so this paper lights no cell and moves no belief. It is still indexed, cited and linked below.
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.
Neither the registry nor the abstract names a trial number. If this is a trial report, that itself is worth knowing.
Who cites it
10 citing papers in PubMed, 27 citations in OpenAlex.
- Pharmacological and Mechanistic Interventions for Cognitive Impairment Associated With Schizophrenia: A Review of Registered Clinical Trials.Acta psychiatrica Scandinavica · 2026Review
- Exploring the Analgesic Potential of L-Lysine: Molecular Mechanisms, Preclinical Evidence, and Implications for Pharmaceutical Pain Therapy.Pharmaceutics · 2025Review
- Construction of an Exudative Age-Related Macular Degeneration Diagnostic and Therapeutic Molecular Network Using Multi-Layer Network Analysis, a Fuzzy Logic Model, and Deep Learning Techniques: Are Retinal and Brain Neurodegenerative Disorders Related?Pharmaceuticals (Basel, Switzerland) · 2023Article
- Metabolomics mapping changed after olanzapine therapy in drug-naive schizophrenia patients-the significant impact of gene polymorphisms.Toxicology research · 2022Article
- Article
- Cerebrospinal fluid metabolomics identifies 19 brain-related phenotype associations.Communications biology · 2021Article
- Role of nitric oxide and related molecules in schizophrenia pathogenesis: biochemical, genetic and clinical aspects.Frontiers in physiology · 2015Review
- Synthesis and Characterization of L-Lysine Conjugated Silver Nanoparticles Smaller Than 10 nM.Advanced science, engineering and medicine · 2014Article
- Lysine metabolism in mammalian brain: an update on the importance of recent discoveries.Amino acids · 2013Review
- Potential role of amino acids in pathogenesis of schizophrenia.International journal of health sciencesReview
Corrections and comments
PubMed lists nothing against this paper. Absence here is not a guarantee, only a check that was made.
Authors and funding
9 authors at 3 institutions in 2 countries.
Funding
No grant is acknowledged in the PubMed record.
Abstract
backgroundAccumulating evidence suggests that the brain's nitric oxide (NO) signalling system may be involved in the pathophysiology of schizophrenia and could thus constitute a novel treatment target. The study was designed to investigate the benefit of L-lysine, an amino acid that interferes with NO production, as an add-on treatment for schizophrenia.
methodsL-lysine, 6 g/day, was administered to 10 patients with schizophrenia as an adjunctive to their conventional antipsychotic medication. The study was designed as a single-blinded, cross-over study where patients were randomly assigned to initial treatment with either L-lysine or placebo and screened at baseline, after four weeks when treatment was crossed over, and after eight weeks.
resultsL-lysine treatment caused a significant increase in blood concentration of L-lysine and was well tolerated. A significant decrease in positive symptom severity, measured by the Positive And Negative Syndrome Scale (PANSS), was detected. A certain decrease in score was also observed during placebo treatment and the effects on PANSS could not unequivocally be assigned to the L-lysine treatment. Furthermore, performance on the Wisconsin Card Sorting Test was significantly improved compared to baseline, an effect probably biased by training. Subjective reports from three of the patients indicated decreased symptom severity and enhanced cognitive functioning.
conclusionsFour-week L-lysine treatment of 6 g/day caused a significant increase in blood concentration of L-lysine that was well tolerated. Patients showed a significant decrease in positive symptoms as assessed by PANSS in addition to self-reported symptom improvement by three patients. The NO-signalling pathway is an interesting, potentially new treatment target for schizophrenia; however, the effects of L-lysine need further evaluation to decide the amino acid's potentially beneficial effects on symptom severity in schizophrenia.
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Registered trials
Read under generation 80e0d062 · epoch 390. Bibliography from PubMed, PubMed Central and OpenAlex; grants from NIH RePORTER; trial links from ClinicalTrials.gov; estimates, votes and beliefs from the OpenQuestion graph.