Gender-related Characteristics of Oxidative Stress Severity and Cognitive Impairment in Patients With Schizophrenia.

The gender specificity of the clinical and psychopathological features of schizophrenia is an important factor in this disease. Gender features of neurocognitive deficit in schizophrenia and associated functional and structural disorders of the brain activity are of particular interest to researchers. There are several potential pathogenetic factors of this disease associated with gender, one of which is considered to be oxidative stress. Stress-induced cell death in the prefrontal and anterior frontal regions and reduced brain volume in these regions lead to cognitive and executive decline in patients with schizophrenia. Despite the great interest in the gender factor in schizophrenia pathogenesis, there are currently very few studies on gender differences in the severity of redox imbalance in patients with schizophrenia and their association with neurocognitive deficit. The aim of the study was to reveal the gender specificity of oxidative stress severity in patients with schizophrenia and assess its association with the severity of neurocognitive deficit. The study included 125 patients with schizophrenia and 75 sex- and age-matched healthy volunteers. Sociodemographic and clinical data were studied. Cognitive functions were evaluated using BACS. Blood samples were taken for biochemical studies of the levels of reduced glutathione (GSH), superoxide dismutase (SOD), catalase (CAT) in erythrocyte hemolysate, malonic dialdehyde (MDA), aldehyde-2,4-dinitrophenylhydrazones (ADNPH), ketone-2,4-dinitrophenylhydrazones (KDNPH) in plasma. Levels of oxidative stress markers were assessed by spectrophotometric method. In a sample of patients with schizophrenia, a statistically significantly higher activity of CAT was revealed among women compared to men (T=2.25; p=0.025), however, it was lower than in healthy volunteers. But, at the same time, a higher concentration of protein peroxidation products was found in the peripheral blood of women than in men (ADNPH MCO: T=2.52; p=0.013; KDNPH MCO: Z=-2.26; p=0.017). In the group of healthy volunteers, in contrast to patients with schizophrenia, gender differences in markers of oxidative stress were not found. In women with schizophrenia, single correlations were found between the level of the lipid peroxidation product MDA and the test scores for verbal memory (R=-0.36; p=0.006) and working memory (R=-0.36; p=0.006), antioxidant enzyme activity SOD and motor skills (R=-0.26; p=0.047). In men, on the contrary, multiple correlations of both antioxidants and, mainly, products of lipid and protein peroxidation with cognitive functions assessed using BACS were found. Despite the fact that oxidative stress is more pronounced in women than in men with schizophrenia, associations of redox imbalance with neurocognitive deficit in women is much less pronounced than in men.

Association of antioxidant deficiency and the level of products of protein and lipid peroxidation in patients with the first episode of schizophrenia.

Schizophrenia is considered a multifactorial disease, where one of the pathogenetic links is oxidative stress; however, the results of studies are often contradictory, largely due to significant heterogeneity among study methods. The present study was undertaken to compare the levels of oxidative stress markers in the peripheral blood of patients with a first episode of schizophrenia (FES) and in healthy volunteers (HV). The study included 50 patients with FES and 37 HV. Blood samples were collected for spectrophotometric assessment of reduced glutathione (GSH), superoxide dismutase (SOD), catalase (CAT), malondialdehyde (MDA), aldehyde-2,4-dinitrophenylhydrazone (ADNPH), and ketone-2,4-dinitrophenylhydrazone (KDNPH) in blood plasma. Results showed that in patients with FES compared with HV, a significant decrease in CAT activity and an increase in oxidative modification of proteins (OMP) were found. In both groups, a significant increase in the level of MDA with age was revealed. In patients, the GSH plasma level was inversely proportional to the ADNPH level, and SOD activity was directly proportional to the KDNPH level. In volunteers there was no such correlation; however, there was a direct correlation between CAT activity and the levels of OMP and MDA. In both groups, a moderate direct correlation between peroxidation products was observed. The results confirm that a redox imbalance (a deficiency of antioxidants, in particular CAT, and excess OMP) may be a pathogenetic link in schizophrenia, which is manifested already at an early stage of the disease.

Screening of Depressive Symptoms in a Russian General Population Sample: A Web-based Cross-sectional Study.

BACKGROUND AND OBJECTIVE: Web-based screening of depressive symptoms in general non-clinical population can provide better insights into actual prevalence of depressive symptoms and associated risk factors. To study the current prevalence of depressive symptoms in Russian non-clinical population we conducted screening using an online survey based on Depression subscale of Hospital Anxiety and Depression Scale (HADS-D). METHODS: The online survey covered 2610 Russian-speaking respondents and included HADS-D, questions about sex, age and presence of cardiovascular diseases (CVD) diagnoses or symptoms in respondents. RESULTS: The proportion of respondents with depressive symptoms, estimated by online HADS-D, was 14.4% (11.5% - at subclinical level, 2.9% - at clinical level). The overall HADS-D score was higher in women (p=0.003), in young individuals under 30 y.o vs. participants over 42 y.o. (p=0.004) and in individuals with self-reported CVD symptoms (p=0.00002). Linear regression analysis showed that self-reported CVD symptoms increase HADS-D score (p<0.001), but male sex (p=0.002) and older age (p<0.001) decrease it. Logistic regression showed that CVD symptoms increase the risk of depressive symptoms by HADS-D (p=0.033, OR=1.29), but older age (p=0.015, OR=0.87) and male sex (as a trend, p=0.052, OR=0.80) decrease this risk. CONCLUSION: Online survey based on HADS-D showed new patterns of depressive symptoms prevalence in Russian non-clinical population. Depressive symptoms prevalence did not differ between men and women and was higher among young people. The reported association between depressive symptoms and CVD was confirmed.