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

Abstract

Objective: Oxidative stress has been reported to play a role in the psychopathology of schizophrenia, though only a few studies have investigated the relationship between early-onset schizophrenia and oxidative stress. The aim of the present study is to evaluate the level of oxidative stress and the presence of DNA damage in first-episode psychosis (FEP) in adolescents. Methods: This study was conducted in the Department of Child Psychiatry of the Dicle University Hospital. It included 20 adolescent patients (age 11-17 years) with psychosis (acute psychosis, schizophreniform disorder, or schizophrenia) according to DSM-IV criteria who had received no previous psychiatric therapy (patient group) and 20 age/gender-matched healthy adolescents (control group). Structured psychiatric interviews [Kiddie Schedule for Affective Disorders and Schizophrenia, Present and Lifetime Version (K-SADS-PL) and Positive and Negative Symptom Scale (PANSS)] were conducted on the patients, and the Clinical Global Impressions (CGI) scale was used to evaluate the severity of disease. Glutathione peroxidase (GPx), superoxide dismutase (SOD), coenzyme Q (CoQ), and 8-hydroxy-2-deoxyguanosine (8-OHdG) levels were determined using the ELISA method and commercial ELISA kits. Results: The mean age was 14.5 ± 1.6 years in the FEP group (male-to-female ratio: 8/12) and 14.4 ± 1.5 years in the control group (male-to-female ratio: 8/12). There were no differences between the patient and control groups in terms of SOD, GPx, or 8-OHdG values (p > 0.05). Conclusions: This study on DNA damage and oxidative stress in FEP in adolescents had a small sample size, and our data suggest that oxidative stress is associated with a chronic disease course rather than being an early sign of early-onset schizophrenia.

Oxidative Stress and Inflammation in Early Onset First Episode Psychosis: A Systematic Review and Meta-Analysis

“…Seven studies reported data on oxidative stress or inflammatory markers in EOP compared with healthy controls (Mico et al, 2011; Fraguas et al, 2012; Parellada et al, 2012; Martinez-Cengotitabengoa et al, 2014; Simsek et al, 2016b; Simsek et al, 2016a; Xu et al, 2016). Details of these 7 studies are given in Table 1.…”

“…Due to the small numbers of studies included for each parameter, no meta-regression analyses could be performed. Separate meta-analyses based on 2 papers (Mico et al, 2011; Simsek et al, 2016b) providing specific data on GPx and cell/DNA oxidative damage in EOP patients with a follow-up diagnosis of schizophrenia as compared with controls did not yield significant results either (SMD=1.34 (95% CI: -1.08 to 3.76), P =.279 for GPx, and SMD=1.37 (95% CI:-1.43 to 4,18), P =.338 for cell/DNA oxidative damage). The quality of the included studies was in general low (supplementary Table 1).…”

“…Studies were excluded if they met any of the following hierarchical exclusion criteria: (1) they were not published as original peer-reviewed articles; (2) they did not include a healthy control group; (3) they did not include a first-episode EOP group (to consider this group as ‘first episode’ ‘early onset psychosis group’, all patients included in the study should be experiencing a first episode of psychosis according to DSM-III, DSM-IV, or DSM-IV-TR criteria and should be 18 years old or younger at the onset of psychosis; including brief psychotic disorder, psychotic disorder not otherwise specified, schizophreniform disorder, schizophrenia, mania with psychotic symptoms, and depression with psychotic symptoms; none of the reviewed studies included patients with substance-induced psychosis); and (4) they did not report data (mean and SD) either on inflammatory and/or oxidative markers or data on the statistical comparison of inflammatory and/or oxidative markers between EOP patients and controls. Of the 139 studies, 7 met none of the exclusion criteria and were thus available for the qualitative analysis (Mico et al, 2011; Fraguas et al, 2012; Parellada et al, 2012; Martinez-Cengotitabengoa et al, 2014; Simsek et al, 2016b; Simsek et al, 2016a; Xu et al, 2016). …”

“…The following hierarchical criteria were used to determine the inclusion of overlapping studies: (1) study with the largest EOP group sample for the parameter of interest; (2) study with the largest control group sample for the parameter of interest; (3) most recent publication. Six of the 7 studies (Mico et al, 2011; Parellada et al, 2012; Martinez-Cengotitabengoa et al, 2014; Simsek et al, 2016a, 2016b; Xu et al, 2016) contributed with at least one marker and entered Phase 4.…”

“…Four studies contributed to the 6 independent meta-analyses (Mico et al, 2011; Parellada et al, 2012; Martinez-Cengotitabengoa et al, 2014; Simsek et al, 2016b). Figure 1 shows the PRISMA flow diagram of the systematic literature search strategy.…”