Abstract In the classical descriptions of schizophrenia, Kraepelin and Bleuler recognized disorganization and impoverishment of mental activity as fundamental symptoms. Their classical descriptions also included a tendency to persisting disability. The psychopathological processes underlying persisting disability in schizophrenia remain poorly understood. The delineation of a core deficit underlying persisting disability would be of value in predicting outcome and enhancing treatment. We tested the hypothesis that mental disorganization and impoverishment are associated with persisting impairments of cognition and role function, and together reflect a latent core deficit that is discernible in cases diagnosed by modern criteria. We used Confirmatory Factor Analysis to determine whether measures of disorganization, mental impoverishment, impaired cognition, and role functioning in 40 patients with schizophrenia represent a single latent variable. Disorganization scores were computed from the variance shared between disorganization measures from 3 commonly used symptom scales. Mental impoverishment scores were computed similarly. A single factor model exhibited a good fit, supporting the hypothesis that these measures reflect a core deficit. Persisting brain disorders are associated with a reduction in post-movement beta rebound (PMBR), the characteristic increase in electrophysiological beta amplitude that follows a motor response. Patients had significantly reduced PMBR compared with healthy controls. PMBR was negatively correlated with core deficit score. While the symptoms constituting impoverished and disorganized mental activity are dissociable in schizophrenia, nonetheless, the variance that these 2 symptom domains share with impaired cognition and role function, appears to reflect a pathophysiological process that might be described as the core deficit of classical schizophrenia.

The multilayer dynamic network model has been proposed as an effective method to understand the brain function. In particular, derived from the definition of clustering coefficient in static networks, the temporal clustering coefficient provides a direct measure of the topological stability of dynamic brain networks and shows potential in predicting altered brain functions. However, test–retest reliability and demographic‐related effects on this measure remain to be evaluated. Using a data set from the Human Connectome Project (157 male and 180 female healthy adults; 22–37 years old), the present study investigated: (1) the test–retest reliability of temporal clustering coefficient across four repeated resting‐state functional magnetic resonance imaging scans as measured by intraclass correlation coefficient (ICC); and (2) sex‐ and age‐related effects on temporal clustering coefficient. The results showed that (1) the temporal clustering coefficient had overall moderate test–retest reliability (ICC > 0.40 over a wide range of densities) at both global and subnetwork levels, (2) female subjects showed significantly higher temporal clustering coefficient than males at both global and subnetwork levels, particularly within the default‐mode and subcortical regions, and (3) temporal clustering coefficient of the subcortical subnetwork was positively correlated with age in young adults. The results of sex effects were robustly replicated in an independent REST‐meta‐MDD data set, while the results of age effects were not. Our findings suggest that the temporal clustering coefficient is a relatively reliable and reproducible approach for identifying individual differences in brain function, and provide evidence for demographically related effects on the human brain dynamic connectomes.

No abstract

Background The COVID-19 pandemic has increased psychological stress among adolescents, and the relation between perceived stress (PS) and psychotic-like experiences (PLEs) has been well-established. However, little is known about the role of family functioning (FF) in this relation, especially when adolescents experienced the extended lockdown period with family members. Methods A total of 4807 adolescents completed this retrospective paper-and-pencil survey after school reopening between May 14th and June 6th, 2020 in Hunan Province, China. We measured PS with the Perceived stress scale (PSS-10), PLEs with the eight positive items from Community Assessment of Psychic Experiences (CAPE-8), and FF with the Family APGAR scale. We conducted subgroup analysis based on three FF levels (good, moderate, and poor) determined by previous studies. Finally, correlation and moderation analysis were performed to detect the effect of FF in the relation between PS and PLEs after adjusting for demographic variables. Results Adolescents with poor FF had higher levels of PS and higher prevalence of PLEs compared to those with good FF (both p < 0.001). FF was negatively associated with both PS ( r = −0.34, p < 0.001) and PLEs ( r = −0.29, p < 0.001). Higher FF significantly attenuated the effect of PS on PLEs after adjusting for sex and age (effect = −0.011, bootstrap 95% CI -0.018, −0.005). Conclusion Our findings indicate that well-functioned family could protect against stress-induced PLEs among adolescents during this crisis. Thus family system could be an early interventional target for distressing psychotic-like experiences in youngsters.

Patients with schizophrenia diverge in their clinical trajectories. Such diverge outcomes may result from the resilience provided by antioxidant response system centered on glutathione (GSH). Proton Magnetic Resonance Spectroscopy (1H-MRS) has enabled the precise in vivo measurement of intracortical GSH; but individual studies report highly variable results even when GSH levels are measured from the same brain region. This inconsistency could be due to the presence of distinct subgroups of schizophrenia with varying GSH-levels. At present, we do not know if schizophrenia increases the interindividual variability of intracortical GSH relative to matched healthy individuals. We reviewed all 1H-MRS GSH studies in schizophrenia focused on the Anterior Cingulate Cortex published until August 2021. We estimated the relative variability of ACC GSH levels in patients compared to control groups using the variability ratio (VR) and coefficient of variation ratio (CVR). The presence of schizophrenia significantly increases the variability of intracortical GSH in the ACC (logVR = 0.12; 95% CI: 0.03–0.21; log CVR = 0.15; 95% CI = 0.06–0.23). Insofar as increased within-group variability (heterogeneity) could result from the existence of subtypes, our results call for a careful examination of intracortical GSH distribution in schizophrenia to seek redox-deficient and redox-sufficient subgroups. An increase in GSH variability among patients also indicate that the within-group predictability of adaptive response to oxidative stress may be lower in schizophrenia. Uncovering the origins of this illness-related reduction in the redox system stability may provide novel treatment targets in schizophrenia.

No abstract

The act of will and the action of the body are not two different states…; they do not stand in the relation of cause and effect but are one and the same thing…. The action of the body is nothing but the act of will …. translated into perception. -Arthur Schopenhauer, 1819 1 Our social world is an ever-changing milieu in which boundless verbal and nonverbal signals are generated by fellow humans. To ensure our survival, we must perceive certain regularities from the complexity that surrounds us. A failure to meet this daily challenge may prove costly for some; social encounters trigger several psychiatric symptoms, while social withdrawal reduces their intensity, at least temporarily. 2 For example, disorganization (or formal thought disorder), one of the central features of schizophrenia, presents primarily as a disruption in cooperative communication that occurs in a social context. Though many technical advances now allow us to study "socially" interacting agents in the laboratory (for example, see Kingsbury and colleagues 3 ), psychiatric symptoms are rarely studied in the context of neural mechanisms of social encounters. To tackle this challenge, we need empirical tools to study the dynamic neural framework of social interaction, starting from a 2-person perspective. In this editorial, we first present such a tool: an emerging "active inference" perspective of cooperative communication between 2 individuals. We then introduce the 2-brain problem of formal thought disorder in schizophrenia as an exemplar case of its utility and map resulting theoretical expectations to known signs of this construct. Lastly, we highlight several experimental opportunities that arise from casting of formal thought disorder in the active inference framework.

The multilayer dynamic network model has been proposed as an effective method to understand how the brain functions dynamically. Specially, derived from the definition of clustering coefficient in static networks, the temporal clustering coefficient provides a direct measure of topological stability of dynamic brain networks and shows potential in predicting altered brain functions in both normal and pathological conditions. However, test-retest reliability and demographic-related effects on this measure remain to be evaluated. Using a publicly available dataset from the Human Connectome Project consisting of 337 young healthy adults (157 males/180 females; 22 to 37 years old), the present study investigated: (1) the test-retest reliability of temporal clustering coefficient across four repeated resting-state functional magnetic resonance imaging scans as measured by intraclass correlation coefficient (ICC); and (2) sex- and age-related effects on temporal clustering coefficient. The results showed that (1) the temporal clustering coefficient had overall moderate test-retest reliability (ICC > 0.40 over a wide range of densities) at both global and subnetwork levels; (2) female subjects showed significantly higher temporal clustering coefficient than males at both global and subnetwork levels, in particular within the default-mode and subcortical regions; (3) temporal clustering coefficient of the subcortical subnetwork was negatively correlated with age in young adults. Our findings suggest that temporal clustering coefficient is a reliable and reproducible approach for the identification of individual differences in brain function, and provide evidence for sex and age effects on human brain dynamic connectome.