Amino acids and acylcarnitines as potential metabolomic markers of schizophrenia: new approaches to diagnostics and therapy

Background. Schizophrenia is a socially significant mental illness with insufficiently studied etiology and pathogenesis. A number of hypotheses of schizophrenia pathogenesis (dopamine, glutamate, kinurenin and serotonin hypotheses) bring together the fact that amino acids are precursors or intermediate metabolic products of these metabolites. Amino acids and their metabolites play an important role as significant substrates and regulators in many metabolic pathways.

The aim of this review is to analyze the literature data on the studies of amino acids and acylcarnitines in patients with schizophrenia.

Methods. A literature search was conducted using PubMed databases for articles published in English and covering the period from the first articles on this topic, dated 1977 to April 2019. Combinations of the following keywords were used to search for “schizophrenia”, “antipsychotics” and “amino acids”, “acylcarnitines”, “metabolomics”.

Results. The review summarizes the data on the content of amino acids and acylcarnitines in the peripheral blood of schizophrenia patients and their dynamics in the course of pharmacotherapy with antipsychotic drugs. The potential of determining amino acids as biomarkers of therapeutic response and side effects, as well as their use in the treatment of patients with schizophrenia, are considered.

Conclusion. Further investigation of the spectrum of amino acids and their metabolites with the using of mass spectrometric methods of metabolic analysis can lead to the discovery of new therapeutic targets and strategies, assess their role in the pathophysiology of schizophrenia, identify mechanisms that ensure the development of antipsychotic antipsychotics, and drug-induced side effects antipsychotics, in particular, metabolic syndrome. 

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