Antioxidant defence reduced in early-onset psychosis patients
MedWire News: Patients with early-onset first-episode psychosis (FEP) show deficits in the antioxidant defense system compared with mentally healthy individuals, researchers have found.
Ana González-Pinto (Hospital Santiago, Vitoria, Spain) and team explain: "Oxidative stress-induced impairment of neuronal processes has been reported to be involved in neurodegeneration and also in the pathophysiology of neuropsychiatric diseases such as schizophrenia.
"It represents an imbalance between the oxidant molecules and the antioxidant defense system, and generally occurs as a consequence of increased production of reactive oxygen species, or when the antioxidant defense system is inefficient."
But they add that few published studies have assessed oxidative balance in patients with early-onset FEP, which is associated with increased disease severity compared with the adult-onset form.
The researchers therefore studied blood samples collected from 102 children and adolescents with FEP who had a symptom history of less than 6 months and 95 mentally healthy young people.
Oxidative stress was evaluated by measuring primary enzymatic antioxidant defense (cellular glutathione peroxidase, catalase, and superoxide dismutase activity) and plasma levels of total antioxidants, glutathione, and lipid peroxidation.
The researchers found that FEP patients had decreased antioxidant defense compared with controls, as indicated by reduced total antioxidant status (0.95 vs 1.26 mM) and reduced glutathione levels (394.12 vs 324.38 µM).
They also found that lipid hydroperoxide levels, indicating lipid damage, were higher in FEP patients than controls (9.15 vs 6.17), as was glutathione peroxidase activity (1028.91 vs 913.06 mU/ml).
González-Pinto et al conclude in the journal BMC Psychiatry: "Our study shows a decrease in the antioxidant defense system in early-onset FEP patients."
They add: "Oxidative damage is present in these patients and, although it may not be the main cause of psychosis, it may contribute to the pathophysiology and account for a deteriorating course and poor outcome in this early-onset group"
MedWire (www.medwire-news.md) is an independent clinical news service provided by Current Medicine Group, a trading division of Springer Healthcare Limited. © Springer Healthcare Ltd; 2011
By Mark Cowen