Major depressive disorder (MDD) is among the most prevalent mental disorders worldwide. Factors causing the pathogenesis of MDD include gut microbiota (GM), which interacts with the host through the gut–brain axis. In previous studies of GM in MDD patients, 16S rRNA sequencing was used, which provided information about composition but not about function. In our study, we analyzed whole metagenome sequencing data to assess changes in both the composition and functional profile of GM. We looked at the GM of 36 MDD patients, compared with that of 38 healthy volunteers. Comparative taxonomic analysis showed decreased abundances of Faecalibacterium prausnitzii, Roseburia hominis, and Roseburia intestinalis, and elevated abundances of Escherichia coli and Ruthenibacterium lactatiformans in the GM of MDD patients. We observed decreased levels of bacterial genes encoding key enzymes involved in the production of arginine, asparagine, glutamate, glutamine, melatonin, acetic, butyric and conjugated linoleic acids, and spermidine in MDD patients. These genes produced signature pairs with Faecalibacterium prausntizii and correlated with decreased levels of this species in the GM of MDD patients. These results show the potential impact of the identified biomarker bacteria and their metabolites on the pathogenesis of MDD, and should be confirmed in future metabolomic studies.

Background. In 2020, the COVID-19 pandemic evoked a variety of research into the virus and its effects on mental health. A variety of mental health and psychological problems have been reported: stress, anxiety, depressive symptoms, insomnia, denial, stigma, anger and fear. Objectives. To assess the level of anxiety, depression and distress in the general population during the lockdown in Russia and to reveal factors associated with distress. Methods. An online survey was carried out from 22-27 April 2020 (the fourth week of lockdown) among the general population (mostly Moscow residents). The survey questions covered general information about people's social and demographic characteristics, experience of COVID-19, health condition (physical and mental), attitudes and views on the pandemic, and the need for psychological support. The survey included the Hospital Anxiety and Depression Scale (HADS) and evaluation of the preceding week's subjective distress level using a visual numeric scale (from 0 to 10). We also asked respondents to specify the causes of distress, adopted from the WHO information sheet relating to the major psychological challenges of the COVID-19 pandemic. Results. In total, 352 responses were collected (men = 74, women = 278; age (M ± SD) = 36.81 ± 11.36 y.o.). Most respondents (n = 225, 63.92%) did not have any personal experience of the coronavirus infection. Normal levels of anxiety and depression scores were prevalent in the sample. Higher than normal levels of HADS anxiety/ depression (> 7 scores) were observed in 105 (29.83%) and 59 (16.76%) respondents, respectively; mean (95% CI) scores for HADS anxiety/depression were 6.23 [5.77, 6.68] /4.65 [4.22, 5.08] (women) and 4.20 [3.32, 5.09] /3.46 [2.63, 4.29] (men), respectively. The leading causes of distress were: 1) the risk of financial problems in the future (n = 267, 76.3%); 2) violation of plans and the disruption to normal life (n = 235, 67.1%; and n = 240, 68.6%, respectively); 3) the health of elderly or chronically diseased relatives (n = 205, 58.6%) and 4) being in self-isolation (n = 186, 53.1%).

Research has suggested that negative symptoms in psychotic disorders may be in part be fueled by deficits in metacognition or the ability to form integrated idea about oneself in others. One limitation of this work is that it has largely come from North America and Western Europe. To further the literature, we assessed symptoms using the Positive and Negative Syndrome Scale and Metacognition using the Metacognitive Assessment Scale -Abbreviated in a sample of outpatients with prolonged schizophrenia (n=41), early episode psychosis (n= 37) and major depression (n=30) gathered in Moscow, Russia. Verbal memory

We investigated the associations of rs4680 COMT, rs6280 DRD3, and rs7322347 5HT2A with youth-onset schizophrenia in the Russian population in a case–control study, and the role of the genotype in the severity of clinical features. The association between rs7322347 and schizophrenia (p = 0.0001) is described for the first time. Furthermore, we found a link with rs6280 and rs4680 in females (p = 0.001 and p = 0.02 respectively) and with rs7322347 in males (p = 0.002). Clinical symptoms were assessed on three scales: the Clinician-Rated Dimensions of Psychosis Symptom Severity scale, Positive and Negative Syndrome Scale, and Frontal Assessment Battery. Gender differences in clinical features are of particular interest. In our study we found gender differences in the severity of clinical features—higher scores for delusions (Positive and Negative Syndrome Scale and Diagnostic and Statistical Manual of Mental Disorders, Fifth Edition) in males and higher scores for depression, delusions, somatic concern, motor retardation, poor attention were found in females.

Objective Schizophrenia may reflect an interactive network of disturbances in cognition. In this study we have examined the relationship between two forms of cognition: metacognition and social cognition among a sample with schizophrenia (n = 41), early episode psychosis (n = 37), and major depression (n = 30) gathered in Moscow, Russia. Methods Metacognition was assessed with the Metacognition Assessment Scale‐Abbreviated. Social cognition was assessed with the Ekman 60 Faces Test and the Interpersonal Reactivity Index. Verbal memory and global psychopathology were included as potential covariates. Results Partial correlations controlling for demographics, neurocognition, and psychopathology revealed greater metacognitive capacity was linked to better facial emotion recognition and perspective taking in the prolonged schizophrenia group. Greater metacognitive capacity in the early psychosis group was linked with greater facial emotion recognition. Metacognition and social cognition were not related to one another in the depression group. Conclusions Social cognition and metacognition may be uniquely related in psychosis.