Reduced antioxidant defense in early onset first-episode psychosis: a case-control study

Abstract

BackgroundOur objective is to determine the activity of the antioxidant defense system at admission in patients with early onset first psychotic episodes compared with a control group.MethodsTotal antioxidant status (TAS) and lipid peroxidation (LOOH) were determined in plasma. Enzyme activities and total glutathione levels were determined in erythrocytes in 102 children and adolescents with a first psychotic episode and 98 healthy controls.ResultsA decrease in antioxidant defense was found in patients, measured as decreased TAS and glutathione levels. Lipid damage (LOOH) and glutathione peroxidase activity was higher in patients than controls. Our study shows a decrease in the antioxidant defense system in early onset first episode psychotic patients.ConclusionsGlutathione deficit seems to be implicated in psychosis, and may be an important indirect biomarker of oxidative stress in early-onset schizophrenia. Oxidative damage is present in these patients, and may contribute to its pathophysiology.

Assessment of serum level of total glutathione in a sample of schizophrenic patients versus bipolar patients

“…Our study detected a nonsignificant correlation between the duration of illness and level of GSH in the schizophrenic group, which supported the results of Micó et al [22] who determined the activity of the antioxidant defense system at admission in patients with early-onset first psychotic episodes compared with a control group. They found that the antioxidant defense system seems to be decreased in patients with a first early-onset psychotic episode, who were either treatment naïve or had been treated with antipsychotics for only a short time when the blood samples were taken at admission.…”

“…Michelet et al [21] reached the same conclusion: they found a statistically significant positive correlation between smoking and level of GSH. Further, in our study there was no significant correlation between level of GSH and smoking in schizophrenic and bipolar patients, which is in concordance with some studies that failed to find a significant association between any of the oxidative stress variables and tobacco use, with subjects being classified as smokers if they reported using tobacco on a daily basis [22]. Our results also agree with a study that detected lower total GSH and reduced GSH in bipolar patients compared with healthy controls; there were no differences in GSH levels between cigarette smokers and nonsmokers in this group of bipolar patients [23].…”

“…These results are in concordance with the results of Matsuzawa et al [24] who found a significant negative correlation between GSH levels and severity of negative symptoms in patients. In contrast, Micó et al [22] found no association between any of the oxidative stress variables and positive symptoms (PANSS positive) and depressive symptoms. Further, there was no correlation between the biochemistry of GSH and disease symptoms [24].…”

Oxidative Stress and DNA Damage in Untreated First-Episode Psychosis in Adolescents

“…Studies of both adolescent and adult patients with FEP have reported deficiencies mostly in antioxidant defense mechanisms (enzymatic and nonenzymatic) and they have implicated oxidative stress in the pathophysiology of schizophrenia (particularly with regard to a negative symptomatology and cognitive functioning) [16,21,29]. A study of 102 children and adolescents by Micó et al [30] reported a decrease in total antioxidant defense GSH levels and an increase in GPx, catalase, and SOD activity, while a study of 48 children and adolescents by Fraguas et al [22] found a relationship between the decrease in GSH levels and the loss of cortical gray matter over 2 years. A study of 105 children and adolescents by Martínez-Cengotitabengoa et al [21] reported lower total antioxidant and GSH levels and a direct relationship between antioxidant defense capacity and global cognition at baseline and after a 2-year follow-up period.…”

Towards stage specific treatments: Effects of duration of illness on therapeutic response to adjunctive treatment with N-acetyl cysteine in schizophrenia

“…There has been significant interest in glutathione (GSH) which is the brain's primary antioxidant and is also involved in the modulation of glutamate (Berk, Ng et al, 2008). Specific decreases in GSH have been observed in those with early onset psychosis at the time of the firstepisode (Mico et al, 2011). Furthermore, GSH reductions were related to a greater loss of cortical grey matter two years later (Fraguas et al, 2012), suggesting that oxidative damage is present at early stages of the illness and may play a key role on pathophysiological processes.…”