Late onset schizophrenia and delusional disorder: activity of platelet energy, glutamate, and glutathione metabolizing enzymes

Abstract

Introduction Alterations of glutamate, energy and glutathione metabolism contribute to the pathogenesis of psychotic disorders Objectives Revealing clinical-biological correlations in patients with late onset schizophrenia and delusional disorder by determining clinical parameters and activity of platelet enzymes of energy, glutamate, and glutathione metabolism. Methods 27 women of 45-80 years old were studied, with late onset schizophrenia or delusional disorder. Activity of platelet cytochrome c-oxidase (COX), glutamate dehydrogenase (GDH), glutathione reductase (GR) and glutathione-S-transferase (GST), and scores by PANSS, HAMD, MMSE, and CGI-S were evaluated twice: before and after the 28-th day of treatment. Activity of COX, GDH, GR, and GST was measured once in 23 women of 44-81 years old comprising the control group. Results As compared with controls, only GDH activity was found significantly decreased (before and after treatment, p<0.001). Clusterisation of patients by enzymatic activities resulted in 3 clusters significantly different by COX, GDH and GST. Significant correlations were found between enzymatic activities and scores by psychometric scales: in the cluster 1 (n=9) baseline COX activity correlated with scores by PANSS positive subscale (R=0.9, p=0.001) and with scores by MMSE (R=-0.9, p=0.002); in the cluster 2 (n=12) GR activity after treatment negatively correlated with scores by PANSS (R=-0.9, p=0.001), PANSS negative subscale (R=-0.8, p=0.004), and CGI-S (R=-0.9, p=0.001). Conclusions The revealed correlations between enzymatic activities and clinical parameters give hope on detection of useful biochemical markers which, after enlargement of patients’ group with late onset psychotic disorders, would be validated for prediction of the pharmacotherapy efficiency and outcome of treatment. Disclosure No significant relationships.

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“…However, when examining the implications for altered glutamate and GABA metabolism in the dorsolateral prefrontal cortexes of older patients with schizophrenia, no significant differences were observed in the levels of GDH activity in these areas between the test and control groups [216]. In late-onset schizophrenia and delusional disorders, changes in glutamate and glutathione metabolism, including changes in metabolic enzymes such as GDH, affect the course of the illness [217]. It was also shown that serum GDH activity tended to be lower in people with schizophrenia with late dyskinesia than in people with schizophrenia without it [218].…”