Activity of enzymes of glutamate, energy and glutathione metabolism in the first juvenile depression with attenuated symptoms of schizophrenia

Abstract

To reveal clinical and biological correlations in patients with attenuated symptoms of schizophrenia in the first juvenile depression, namely, the correlation between SOPS and HDRS-21 scores and the levels of activities of glutathione, glutamate and energy metabolism enzymes in the blood of patients. The study included 81 young men, aged 16-25 years, with the first depressive episode (ICD-10 items F32.1, F32.2, F32.38, F32.8), from which the groups with predominantly attenuated positive symptoms (group 1, n=36) and predominantly attenuated negative symptoms (group 2, n=24), and a group without attenuated schizophrenia symptoms (group 3, n=21) were selected. The control group consisted of 20 mentally healthy men aged 19-25 years. Psychometric methods (SOPS and HDRS-21) and psychopathological methods were used. Activities of cytochrome c oxidase (COX), glutamate dehydrogenase (GDH), glutathione reductase (GR), and glutathione S-transferase (GST) enzymes were determined spectrophotometrically in blood cells. When compared with the control group, activities of platelet GDH, GR, and GST (before and after treatment) were significantly reduced in groups 1, 2, 3 (Mann-Whitney U-test, p<0.0002, p<0.001 and p<0.0001, respectively); the activity of erythrocyte GST was reduced in group 1, and the activities of erythrocyte GR and GST were reduced in group 3 (p<0.05). In group 1, baseline COX (before treatment) was positively correlated with post-treatment SOPS-N scores (R=0.580, p=0.0003), while baseline erythrocyte GR was negatively correlated with post-treatment HDRS-21 scores (R=-0.591, p=0.0004). In group 2, baseline GDH levels were positively correlated with post-treatment scores on SOPS-P (R=0.425, p=0.0384), SOPS-N (R=0.500, p=0.0129), SOPS total (R=0.526, p=0.0083) and HDRS-21 (R=0.479, p=0.0180). The discovery of clinical and biological correlations in groups of patients with attenuated symptoms of schizophrenia in the structure of juvenile depression contributes to understanding the pathogenetic mechanisms of the formation of a high clinical risk of psychosis and contributes to the search for markers of the initial stages of schizophrenia.