Neurocognitive impairment in deficit and non-deficit schizophrenia: a meta-analysis

Altered patterns of dynamic functional connectivity of brain networks in deficit and non-deficit schizophrenia

This study aims to investigate the altered patterns of dynamic functional network connectivity (dFNC) between deficit schizophrenia (DS) and non-deficit schizophrenia (NDS), and further explore the associations with cognitive impairments. 70 DS, 91 NDS, and 120 matched healthy controls (HCs) were enrolled. The independent component analysis was used to segment the whole brain. The fMRI brain atlas was used to identify functional networks, and the dynamic functional connectivity (FC) of each network was detected. Correlation analysis was used to explore the associations between altered dFNC and cognitive functions. Four dynamic states were identified. Compared to NDS, DS showed increased FC between sensorimotor network and default mode network in state 1 and decreased FC within auditory network in state 4. Additionally, DS had a longer mean dwell time of state 2 and a shorter one in state 3 compared to NDS. Correlation analysis showed that fraction time and mean dwell time of states were correlated with cognitive impairments in DS. This study demonstrates the distinctive altered patterns of dFNC between DS and NDS patients. The associations with impaired cognition provide specific neuroimaging evidence for the pathogenesis of DS.

Brief Report: Intact Cognitive Functions in Children and Adolescents of Parents With Mood Disorders

OBJECTIVES

We aimed to identify if offspring of a parent with mood disorders presented cognitive deficits on 14 cognitive subtests while controlling for intellectual quotient, anxio-depressive symptoms, symptoms of attention deficit hyperactivity disorder (ADHD) or insomnia.

METHODS

Using the Healthy Brain Network biobank, we identified 44 offspring of a parent with bipolar disorder (BD), 87 offspring of a parent with major depressive disorder (MDD) and 88 offspring of healthy parents. Analyses of variance (ANOVA) were performed to determine if groups differed on 14 subtests of the Wechsler Intelligence Scale for Children-5th Edition (WISC) and National Institutes of Health toolbox.

RESULTS

Across all subtests, groups did not significantly differ. Only a subtle effect was found for male participants in which high-risk participants exhibited lower scores on the mental rotation subtest compared to the control group.

CONCLUSION

Overall, our results suggest intact cognition in young offspring of parents with a mood disorder.

The associations of negative and disorganization symptoms with verbal fluency in schizophrenia: the mediation effect of processing speed and cognitive flexibility

BACKGROUND

Psychopathological symptoms appear important for cognitive functions in schizophrenia. Nevertheless, the factors and their impact on relationships between negative or disorganization symptoms and verbal fluency are still debatable. The preliminary objective of the study was to compare verbal fluency, including clustering and switching as cognitive strategies, executive functions, and processing speed between individuals with schizophrenia (SZ) and healthy controls (HC). The main aim of the study was to investigate mediation models and identify whether relationships between negative and disorganization symptoms and verbal fluency in schizophrenia are mediated by cognitive flexibility and processing speed.

METHODS

Semantic (animal and fruit) and phonemic (letter k and letter f) fluency tasks, the Berg Card Sorting Test (BCST), and the Color Trails Test (CTT) were administered in the SZ group (n = 108) and a matched HC group (n = 108). The Positive and Negative Syndrome Scale (PANSS) was applied to measure psychopathological symptoms in schizophrenia patients.

RESULTS

SZ produced fewer words, had larger cluster size, and fewer switches in semantic fluency than HC. Moreover, the SZ group had longer completion time in CTT 1 and CTT 2 and higher percent of perseverative and non-perseverative errors in BCST than HC. Three mediation models demonstrated good fit indices, suggesting that processing speed and cognitive flexibility were significant mediators for relationships between: (1) psychopathological symptoms and productivity or semantic clustering in animal fluency; (2) negative symptoms and productivity in semantic or phonemic fluency; and (3) disorganization symptoms and productivity in semantic fluency.

CONCLUSIONS

Individuals with schizophrenia are characterized by a specific performance profile on verbal fluency tasks. They manifest poor productivity and problems using cognitive strategies for semantic fluency. Referring to executive functioning, schizophrenia patients exhibit decreased cognitive flexibility, problem-solving, and formulating concepts, as well as slow processing speed. It was found that processing speed and cognitive flexibility may be understood as the neuropsychological mechanisms modifying the relationships between negative symptoms, disorganization symptoms, and semantic and phonemic fluency. Therefore, these results provide a foundation for including cognitive flexibility and processing speed in cognitive remediation for schizophrenia patients.

Neurobehavioral characteristics and symptomatic correlations of audiovisual multisensory integration in schizophrenia: A systematic review and meta-analysis

BACKGROUND

Multisensory integration (MSI) avoids cognitive overload, and the traditional all-or-nothing perspective for dysfunctional MSI in schizophrenia has been increasingly challenged. This study aimed to systematically review and meta-analyze extant evidence on audiovisual MSI in schizophrenia.

METHODS

We searched Web of Science, PubMed, PsycINFO and PsycARTICLES databases from inception until April 16th, 2024. Studies using appropriate audiovisual integration tasks to compare either behavioral or neural responses between schizophrenia individuals and healthy controls were included. Primary outcome measures included between-group differences (Hedge's g) and symptomatic correlations (Fisher's z) in three components of audiovisual integration tasks, including audiovisual processing, adaptation and integration. The multilevel random-effects models were used to address statistical dependency.

RESULTS

In total, 209 between-group and 116 correlational effect sizes were synthesized from 46 studies, representing 1108 non-overlapped schizophrenia participants and 1084 healthy controls. The overall dysfunctional audiovisual MSI in schizophrenia (g = -0.50, [95 % CI, -0.64 to -0.37]) was primarily ascribed to the impaired audiovisual processing (g = -0.53, [95 % CI, -0.71 to -0.35]) and adaptation (g = -0.71, [95 % CI, -0.99 to -0.42]), rather than integration itself (g = -0.23, [95 % CI, -0.56 to 0.11]). Pooled correlational effect size was extremely small (z = 0.16, [95 % CI, 0.03 to 0.30]).

CONCLUSIONS

Individuals with schizophrenia show dysfunctional multisensory processing and adaptation, but preserve a less impaired multisensory integration ability. Our findings provide implications for clinical interventions, as the relatively preserved audiovisual integration ability may serve as a possible avenue for cognitive training programs.

Comparative Analysis of Social Cognitive and Neurocognitive Performance Across Autism and Schizophrenia Spectrum Disorders

BACKGROUND AND HYPOTHESIS

Social cognitive and neurocognitive performance is impacted in autism and schizophrenia spectrum disorders (SSDs). Here, we compared social cognitive and neurocognitive performance across a large transdiagnostic sample of participants with autism, SSDs, and typically developing controls (TDCs).

STUDY DESIGN

Participants (total N = 584; autism N = 100, SSDs N = 275, TDCs N = 209; aged 16-55 years; 61% male assigned at birth) completed lower-level (eg, emotion processing) and higher-level (eg, theory of mind) social cognitive tasks, the MATRICS Consensus Cognitive Battery, and a measure of social functioning. Nonparametric groupwise comparisons were undertaken, adjusting for age and sex, and within-group correlations were used to examine associations between social cognition, neurocognition, and social functioning.

STUDY RESULTS

Autistic and SSD groups performed worse than TDCs on lower- and higher-level social cognitive tasks, with few autism-SSD differences found. Autism and SSDs had lower neurocognitive scores than TDCs; SSDs demonstrated lower processing speed, working memory, verbal learning, and visual learning versus autism. Positive associations between social cognitive tasks and neurocognition were observed across groups, and self-reported measures of empathy were consistently correlated with social functioning.

CONCLUSIONS

This study represents the largest transdiagnostic comparison of both social cognition and neurocognition in an autism/SSD sample reported to date. Autistic participants and those with SSDs showed similar performance on lower- and higher-level social cognitive tasks relative to controls, while neurocognition was less impacted in autism versus SSDs. These findings underscore the importance of transdiagnostic research into the mechanisms underlying social cognitive deficits and highlight the potential for developing transdiagnostic interventions.

Identifying neurobiological heterogeneity in clinical high-risk psychosis: a data-driven biotyping approach using resting-state functional connectivity

To explore the neurobiological heterogeneity within the Clinical High-Risk (CHR) for psychosis population, this study aimed to identify and characterize distinct neurobiological biotypes within CHR using features from resting-state functional networks. A total of 239 participants from the Shanghai At Risk for Psychosis (SHARP) program were enrolled, consisting of 151 CHR individuals and 88 matched healthy controls (HCs). Functional connectivity (FC) features that were correlated with symptom severity were subjected to the single-cell interpretation through multikernel learning (SIMLR) algorithm in order to identify latent homogeneous subgroups. The cognitive function, clinical symptoms, FC patterns, and correlation with neurotransmitter systems of biotype profiles were compared. Three distinct CHR biotypes were identified based on 646 significant ROI-ROI connectivity features, comprising 29.8%, 19.2%, and 51.0% of the CHR sample, respectively. Despite the absence of overall FC differences between CHR and HC groups, each CHR biotype demonstrated unique FC abnormalities. Biotype 1 displayed augmented somatomotor connection, Biotype 2 shown compromised working memory with heightened subcortical and network-specific connectivity, and Biotype 3, characterized by significant negative symptoms, revealed extensive connectivity reductions along with increased limbic-subcortical connectivity. The neurotransmitter correlates differed across biotypes. Biotype 2 revealed an inverse trend to Biotype 3, as increased neurotransmitter concentrations improved functional connectivity in Biotype 2 but reduced it in Biotype 3. The identification of CHR biotypes provides compelling evidence for the early manifestation of heterogeneity within the psychosis spectrum, suggesting that distinct pathophysiological mechanisms may underlie these subgroups.

Association of clozapine with structural and resting-state functional abnormalities of the hippocampus in chronic schizophrenia

Introduction

Abnormalities in the hippocampus have been extensively reported in schizophrenia research. However, inconsistent findings exist, and how structural and functional abnormalities of the hippocampus are associated with clinical symptoms in schizophrenia, especially concerning clozapine treatment, remains uncertain.

Methods

We recruited 52 patients with schizophrenia, each with an illness duration of at least 5 years, and categorized them based on clozapine treatment. T1-weighted images and resting-state functional magnetic resonance imaging scans were obtained and analyzed to perform group comparisons of the structural and functional changes in the hippocampus. Volumes of the hippocampal subregions, as well as resting-state functional connectivity maps from these areas were compared between the groups. Associations with clinical symptoms, including the severity of psychiatric symptoms and cognitive functions, were investigated.

Results

The clozapine group (n=23) exhibited smaller volumes in several hippocampal subregions, including the CA1, CA4, granule cell and molecular layers of the dentate gyrus, compared to the non-clozapine group (n=29). Seven clusters with significant group differences in functional connectivity with these hippocampal subregions were identified, with six of these clusters showing increased functional connectivity in the clozapine group. The reduced volumes of the hippocampal subregions were moderately associated with the severity of negative symptoms, general intelligence, and executive function.

Discussion

Patients with schizophrenia undergoing clozapine treatment exhibited smaller volumes in the hippocampal subregions, which were moderately associated with negative symptoms and cognitive functions, compared to those without clozapine treatment.

Analysis of the status quo and clinical influencing factors of the social cognitive impairment in deficit schizophrenia

Background

Due to the high heterogeneity of schizophrenia, the factors influencing social cognitive impairment are controversial. The purpose of this study was to investigate the social cognitive dysfunction of deficit schizophrenia (DS), and to explore its clinical impact on the clinical characteristics and neurocognitive function assessment results.

Methods

This study involved 100 DS patients, 100 non-deficit schizophrenia (NDS) patients, and 100 healthy controls (HC). Social cognitive functions were assessed using the Eye Complex Emotion Discrimination Task (ECEDT), Game of Dice Task (GDT), and Iowa Gambling Task (IGT), while neurocognitive functions were examined using the Clock Drawing Task (CDT), the Verbal Fluency Task (VFT), Digit Span Test (DST), Stroop Color-word Test (SCWT), and Trail Making Test (TMT). We analyzed the differences in cognitive function among the three groups of patients and the correlation between cognitive function assessment results and Positive and Negative Syndrome Scale (PANSS) scores.

Results

Comparison of neurocognitive functions among the three groups through CDT, VFT, DST, SCWT, and TMT revealed that in the values of these tests in the DS group differed significantly from those of the NDS and HC groups. However, the DSB of the NDS group was lower and the TMT results were significantly higher than those of the HC group. In the DS group, ECEDT emotion recognition was positively correlated with stroop colors and stroop interference; the score of gender recognition was positively correlated with VFT, DSF, and SCWT, and TMT-B; the total time spent was positively correlated with TMT; The GDT risky option was negatively correlated with VFT, DST, stroop word, and stroop interference; the negative feedback utilization was negatively correlated with PANSS-Negative; TMT was positively correlated with VFT; IGT was positively correlated with CDT, VFT, DST, and SCWT, but it was negatively correlated with PANSS-Negative and TMT, with statistically significant.

Conclusion

There are significant social cognitive impairments in the perception of social information, judgment and resolution of social problems in deficit schizophrenia, which are closely related to negative symptoms and multidimensional neurocognitive dysfunction such as attention, learning, memory, brain information processing speed, cognitive flexibility, and functional executive power.

Conceptualization and characterization of "primary" and "secondary" cognitive impairment in schizophrenia

Cognitive impairment represents one of the core features of schizophrenia, involves both neurocognition and social cognition domains, and has a significant negative impact on real-world functioning. The present review provides a framework for the conceptualization and characterization of "primary" and "secondary" cognitive impairment in schizophrenia. In this conceptualization, primary cognitive impairment can be defined as a consequence of the neurobiological alterations that underlie psychopathological manifestations of the disorder, while secondary cognitive impairment can be defined as the results of a source issue that has a negative impact on cognitive performance. Sources of secondary cognitive impairment are frequent in people with schizophrenia and include several different factors, such as positive and negative symptoms, depressive symptoms, autistic symptoms, pharmacotherapy, substance abuse, metabolic syndrome, social deprivation, and sleep disorders. It can be hypothesized that secondary cognitive impairment may be improved by effectively resolving the source issue, while primary cognitive impairment may benefit from dedicated treatment. Further research is required to confirm this hypothesis, to better characterize the distinction between primary and secondary cognitive impairment in a clinical and in a neurobiological perspective, and to evaluate the impact of systematically assessing and treating secondary cognitive impairment.

Cognitive Mechanisms of Aberrant Self-Referential Social Perception in Psychosis and Bipolar Disorder: Insights From Computational Modeling

BACKGROUND AND HYPOTHESIS

Individuals with schizophrenia (SZ) and bipolar disorder (BD) show disruptions in self-referential gaze perception-a social perceptual process related to symptoms and functioning. However, our current mechanistic understanding of these dysfunctions and relationships is imprecise.

STUDY DESIGN

The present study used mathematical modeling to uncover cognitive processes driving gaze perception abnormalities in SZ and BD, and how they relate to cognition, symptoms, and social functioning. We modeled the behavior of 28 SZ, 38 BD, and 34 controls (HC) in a self-referential gaze perception task using drift-diffusion models parameterized to index key cognitive components: drift rate (evidence accumulation efficiency), drift bias (perceptual bias), start point (expectation bias), threshold separation (response caution), and nondecision time (encoding/motor processes).

STUDY RESULTS

Results revealed that aberrant gaze perception in SZ and BD was driven by less efficient evidence accumulation, perceptual biases predisposing self-referential responses, and greater caution (SZ only). Across SZ and HC, poorer social functioning was related to greater expectation biases. Within SZ, perceptual and expectancy biases were associated with hallucination and delusion severity, respectively.

CONCLUSIONS

These findings indicate that diminished evidence accumulation and perceptual biases may underlie altered gaze perception in patients and that SZ may engage in compensatory cautiousness, sacrificing response speed to preserve accuracy. Moreover, biases at the belief and perceptual levels may relate to symptoms and functioning. Computational modeling can, therefore, be used to achieve a more nuanced, cognitive process-level understanding of the mechanisms of social cognitive difficulties, including gaze perception, in individuals with SZ and BD.

Negative symptoms and neurocognition in drug-naïve schizophrenia: moderating role of plasma neutrophil gelatinase-associated lipocalin (NGAL) and interferon-gamma (INF-γ)

Previous studies reported that peripheral inflammation was associated with cognitive performance and brain structure in schizophrenia. However, the moderating effect of inflammation has not been extensively studied. This study investigated whether inflammation markers moderated the association between negative symptoms and neurocognition in schizophrenia. This cross-sectional study included 137 drug-naïve schizophrenia patients (DNS) and 67 healthy controls (HC). We performed the Measurements and Treatment Research to Improve Cognition in Schizophrenia (MATRICS) Consensus Cognitive Battery (MCCB) for cognitive assessment and the Positive and Negative Syndrome Scale (PANSS) for psychiatric symptoms. Plasma concentrations of interferon-gamma (IFN-γ), neutrophil gelatinase-associated lipocalin (NGAL), and nuclear factor kappa B (NF-κB) were measured. The MCCB neurocognition score, social cognition score, and total score; the plasma concentrations of NGAL, IFN-γ, and NF-κB were significantly decreased in DNS than in HC (all P's < 0.001). PANSS negative subscale (PNS), PANSS reduced expressive subdomain (RES) negatively correlated with neurocognition score (P = 0.007; P = 0.011, respectively). Plasma concentrations of IFN-γ and NGAL positively correlated with neurocognition score (P = 0.043; P = 0.008, relatively). The interactions of PNS × NGAL; PNS × IFN-γ; RES × IFN-γ accounted for significant neurocognition variance (P = 0.025; P = 0.029, P = 0.007, respectively). Simple slope analysis showed that all the above moderating effects only occurred in patients with near normal IFN-γ and NGAL levels. Plasma concentrations of IFN-γ and NGAL moderated the relationship between negative symptoms (especially RES) and neurocognition in schizophrenia. Treatment targeting inflammation may contribute to neurocognition improvement in schizophrenia.

Positive association between increased homocysteine and deficit syndrome in Chinese patients with chronic schizophrenia: a large-scale cross-sectional study

Emerging studies indicate that oxidative stress may contribute to deficit syndrome (DS) in patients with schizophrenia. Homocysteine (Hcy) is a well-known marker and mediator of oxidative stress that exhibits tight associations with schizophrenia. However, no previous studies have assessed the relationship of DS with Hcy. This study evaluated the prevalence, clinical characteristics, and association of DS with Hcy in 491 patients with schizophrenia. Plasma levels of Hcy and other metabolic parameters were measured. Positive and Negative Syndrome Scale and the proxy scale for deficit syndrome were employed to assess psychiatric symptoms and DS. The logistic regression model was conducted to assess independent factors associated with DS, and the Area Under the Curve (AUC) was used to assess the performance of our model. There was a high incidence of hyperhomocysteinemia (58.8%) and DS (24.4%). Plasma Hcy levels were significantly higher in patients with DS. Age, Hcy levels, and psychiatric symptoms were independently associated with DS. The combination of these variables perfectly differentiated DS and non-DS patients with an AUC value of 0.89. Our study suggests that elevated Hcy levels may be related to DS. Routine monitoring of Hcy is essential and may facilitate early detection of DS in patients with schizophrenia.

Cognitive Mechanisms of Aberrant Self-Referential Social Perception in Psychosis and Bipolar Disorder: Insights from Computational Modeling

Background and Hypothesis

Individuals with schizophrenia (SZ) and bipolar disorder (BD) show disruptions in self-referential gaze perception-a social perceptual process related to symptoms and functioning. However, our current mechanistic understanding of these dysfunctions and relationships is imprecise.

Study Design

The present study used mathematical modeling to uncover cognitive processes driving gaze perception abnormalities in SZ and BD, and how they relate to cognition, symptoms, and social functioning. We modeled the behavior of 28 SZ, 38 BD, and 34 controls (HC) in a self-referential gaze perception task using drift-diffusion models (DDM) parameterized to index key cognitive components: drift rate (evidence accumulation efficiency), drift bias (perceptual bias), start point (expectation bias), threshold separation (response caution), and non- decision time (encoding/motor processes).

Study Results

Results revealed that aberrant gaze perception in SZ and BD was driven by less efficient evidence accumulation, perceptual biases predisposing self-referential responses, and greater caution (SZ only). Across SZ and HC, poorer social functioning was related to greater expectation biases. Within SZ, perceptual and expectancy biases were associated with hallucination and delusion severity, respectively.

Conclusions

These findings indicate that diminished evidence accumulation and perceptual biases may underlie altered gaze perception in patients and that SZ may engage in compensatory cautiousness, sacrificing response speed to preserve accuracy. Moreover, biases at the belief and perceptual levels may relate to symptoms and functioning. Computational modeling can, therefore, be used to achieve a more nuanced, cognitive process-level understanding of the mechanisms of social cognitive difficulties, including gaze perception, in individuals with SZ and BD.

Impulsivity and inhibitory control in deficit and non-deficit schizophrenia

BACKGROUND

There is conflicting evidence on impulsivity and its potential relationship with inhibitory control in schizophrenia. This study therefore aimed to identify differences in impulsivity and cognitive and motor inhibition between patients with deficit (DS) and non-deficit (NDS) schizophrenia and healthy controls (HC). We also explored the relationships between impulsivity and different dimensions of inhibitory control in all studied groups.

METHODS

The sample comprised 28 DS patients, 45 NDS patients, and 39 age-matched HC. A neuropsychological battery was used.

RESULTS

DS patients scored lower in venturesomeness, while those with NDS scored higher in impulsiveness compared to HC. In addition, both groups of patients scored higher on measures of cognitive and motor inhibition, including those relatively independent of information processing speed (although the results were slightly different after adjusting for IQ and/or years of education). Correlations between impulsivity and cognitive inhibition emerged in DS patients, while links between impulsivity and motor inhibition were observed in HC.

CONCLUSIONS

Our results suggest the presence of deficits in experimentally assessed inhibitory control in schizophrenia patients, with predominant impulsivity in the NDS population. In addition, impulsivity may affect the cognitive control of inhibition in deficit schizophrenia. Nevertheless, due to the preliminary nature of these findings, they require further empirical verification in future research.

Modeling the effects of treatment resistance and anticholinergic burden on cognitive function domains in patients with schizophrenia

The contribution of anticholinergic burden to cognitive function in patients with treatment resistant schizophrenia (TRS) is uncertain. This case-control study aims to comprehensively examine the association between treatment resistance and cognitive functions and the contribution of anticholinergic burden in patients with schizophrenia. Anticholinergic burden of all patients was calculated using the Anticholinergic Cognitive Burden scale. Exploratory Factor Analysis of 11 cognitive assessments identified four cognitive domains: verbal memory, attention and general cognitive functions, visual memory and processing speed, and executive function. Two structural equation models (SEM) examined the relationship of TRS and these cognitive functions with, and without considering anticholinergic burden. A total of 288 participants were included (TRS N=111, non-TRS N=177). Patients with TRS performed poorer than the non-TRS group only in the executive function domain. Anticholinergic burden contributed significantly to the attention and general cognitive functions, visual memory and processing speed, and executive function. The impact of TRS on executive function was no longer significant after adding anticholinergic burden to the SEM. Results suggested that anticholinergic burden contributes to a wide range of cognitive function impairment in patients with schizophrenia and is likely to be part of the apparent differences of cognitive function between TRS and non-TRS.

Integrating Clinical Neuropsychology and Psychotic Spectrum Disorders: A Systematic Analysis of Cognitive Dynamics, Interventions, and Underlying Mechanisms

Background and Objectives: The study aims to provide a comprehensive neuropsychological analysis of psychotic spectrum disorders, including schizophrenia, bipolar disorder, and depression. It focuses on the critical aspects of cognitive impairments, diagnostic tools, intervention efficacy, and the roles of genetic and environmental factors in these disorders. The paper emphasizes the diagnostic significance of neuropsychological tests in identifying cognitive deficiencies and their predictive value in the early management of psychosis. Materials and Methods: The study involved a systematic literature review following the PRISMA guidelines. The search was conducted in significant databases like Scopus, PsycINFO, PubMed, and Web of Science using keywords relevant to clinical neuropsychology and psychotic spectrum disorders. The inclusion criteria required articles to be in English, published between 2018 and 2023, and pertinent to clinical neuropsychology's application in these disorders. A total of 153 articles were identified, with 44 ultimately included for detailed analysis based on relevance and publication status after screening. Results: The review highlights several key findings, including the diagnostic and prognostic significance of mismatch negativity, neuroprogressive trajectories, cortical thinning in familial high-risk individuals, and distinct illness trajectories within psychosis subgroups. The studies evaluated underline the role of neuropsychological tests in diagnosing psychiatric disorders and emphasize early detection and the effectiveness of intervention strategies based on cognitive and neurobiological markers. Conclusions: The systematic review underscores the importance of investigating the neuropsychological components of psychotic spectrum disorders. It identifies significant cognitive impairments in attention, memory, and executive function, correlating with structural and functional brain abnormalities. The paper stresses the need for precise diagnoses and personalized treatment modalities, highlighting the complex interplay between genetic, environmental, and psychosocial factors. It calls for a deeper understanding of these neuropsychological processes to enhance diagnostic accuracy and therapeutic outcomes.

Polygenic effects on brain functional endophenotype for deficit and non-deficit schizophrenia

Deficit schizophrenia (DS) is a subtype of schizophrenia (SCZ). The polygenic effects on the neuroimaging alterations in DS still remain unknown. This study aims to calculate the polygenic risk scores for schizophrenia (PRS-SCZ) in DS, and further explores the potential associations with functional features of brain. PRS-SCZ was calculated according to the Whole Exome sequencing and Genome-wide association studies (GWAS). Resting-state fMRI, as well as biochemical features and neurocognitive data were obtained from 33 DS, 47 NDS and 41 HCs, and association studies of genetic risk with neuroimaging were performed in this sample. The analyses of amplitude of low-frequency fluctuation (ALFF), regional homogeneity (ReHo) and functional connectivity (FC) were performed to detect the functional alterations between DS and NDS. In addition, correlation analysis was used to investigate the relationships between functional features (ALFF, ReHo, FC) and PRS-SCZ. The PRS-SCZ of DS was significantly lower than that in NDS and HC. Compared to NDS, there was a significant increase in the ALFF of left inferior temporal gyrus (ITG.L) and left inferior frontal gyrus (IFG.L) and a significant decrease in the ALFF of right precuneus (PCUN.R) and ReHo of right middle frontal gyrus (MFG.R) in DS. FCs were widely changed between DS and NDS, mainly concentrated in default mode network, including ITG, PCUN and angular gyrus (ANG). Correlation analysis revealed that the ALFF of left ITG, the ReHo of right middle frontal gyrus, the FC value between insula and ANG, left ITG and right corpus callosum, left ITG and right PCUN, as well as the scores of Trail Making Test-B, were associated with PRS-SCZ in DS. The present study demonstrated the differential polygenic effects on functional changes of brain in DS and NDS, providing a potential neuroimaging-genetic perspective for the pathogenesis of schizophrenia.

Profiling gut microbiota signatures associated with the deficit subtype of schizophrenia: Findings from a case-control study

BACKGROUND

Previous studies have reported a variety of gut microbiota alterations in patients with schizophrenia. However, none of these studies has investigated gut microbiota in patients with the deficit subtype of schizophrenia (D-SCZ) that can be characterized by primary and enduring negative symptoms. Therefore, in this study we aimed to profile gut microbiota of individuals with D-SCZ, compared to those with non-deficit schizophrenia (ND-SCZ) and healthy controls (HCs).

METHODS

A total of 115 outpatients (44 individuals with D-SCZ and 71 individuals with ND-SCZ) during remission of positive and disorganization symptoms as well as 120 HCs were enrolled. Gut microbiota was analyzed using the 16 rRNA amplicon sequencing. Additionally, the levels of C-reactive protein (CRP), glucose and lipid metabolism markers were determined in the peripheral blood samples.

RESULTS

Altogether 14 genera showed differential abundance in patients with D-SCZ compared to ND-SCZ and HCs, including Candidatus Soleaferrea, Eubacterium, Fusobacterium, Lachnospiraceae UCG-002, Lachnospiraceae UCG-004, Lachnospiraceae UCG-010, Libanicoccus, Limosilactobacillus, Mogibacterium, Peptococcus, Prevotella, Prevotellaceae NK3B31 group, Rikenellaceae RC9 gut group, and Slackia after adjustment for potential confounding factors. Observed alterations were significantly associated with cognitive performance in both groups of patients. Moreover, several significant correlations of differentially abundant genera with the levels of CRP, lipid profile parameters, glucose and insulin were found across all subgroups of participants.

CONCLUSION

Findings from the present study indicate that individuals with D-SCZ show a distinct profile of gut microbiota alterations that is associated with cognitive performance, metabolic parameters and subclinical inflammation.

Comparison of social cognition and neurocognition in schizophrenia and autism spectrum disorder: A systematic review and meta-analysis

BACKGROUND

This report aimed to compare group differences in social and non-social cognition in autism spectrum disorders (ASD) and schizophrenia, and examine the influence of age and other factors on group differences.

METHODS

Literature searches were conducted in Pubmed and Web of Science from January 1980 to August 2022. Original research articles reporting objective measures of cognition were selected.

RESULTS

57 articles involving 1864 patients with schizophrenia and 1716 patients with ASD have been included. Schizophrenia was associated with more severe non-social-cognitive impairment, particularly in fluency (g=0.47;CI[0.17-0.76]) and processing speed domains (g=0.41;CI[0.20-0.62]). Poorer performance in social cognition (Z = 3.68,p = 0.0002) and non-social cognition (Z = 2.48,p = 0.01) in schizophrenia were significantly related to older age. ASD was associated with more severe social cognitive impairment when groups were matched for non-social-cognition (g=-0.18, p = 0.04) or reasoning/problem solving (g=-0,62; CI [-1,06-(-0.08)].

DISCUSSION

While both disorders present with social and non-social cognitive impairments, the pattern and developmental trajectories of these deficits are different. The limitations included heterogeneity of the cognitive measures, and the lack of sufficient information about antipsychotic use.

Cortical morphology in patients with the deficit and non-deficit syndrome of schizophrenia: a worldwide meta- and mega-analyses

Converging evidence suggests that schizophrenia (SZ) with primary, enduring negative symptoms (i.e., Deficit SZ (DSZ)) represents a distinct entity within the SZ spectrum while the neurobiological underpinnings remain undetermined. In the largest dataset of DSZ and Non-Deficit (NDSZ), we conducted a meta-analysis of data from 1560 individuals (168 DSZ, 373 NDSZ, 1019 Healthy Controls (HC)) and a mega-analysis of a subsampled data from 944 individuals (115 DSZ, 254 NDSZ, 575 HC) collected across 9 worldwide research centers of the ENIGMA SZ Working Group (8 in the mega-analysis), to clarify whether they differ in terms of cortical morphology. In the meta-analysis, sites computed effect sizes for differences in cortical thickness and surface area between SZ and control groups using a harmonized pipeline. In the mega-analysis, cortical values of individuals with schizophrenia and control participants were analyzed across sites using mixed-model ANCOVAs. The meta-analysis of cortical thickness showed a converging pattern of widespread thinner cortex in fronto-parietal regions of the left hemisphere in both DSZ and NDSZ, when compared to HC. However, DSZ have more pronounced thickness abnormalities than NDSZ, mostly involving the right fronto-parietal cortices. As for surface area, NDSZ showed differences in fronto-parietal-temporo-occipital cortices as compared to HC, and in temporo-occipital cortices as compared to DSZ. Although DSZ and NDSZ show widespread overlapping regions of thinner cortex as compared to HC, cortical thinning seems to better typify DSZ, being more extensive and bilateral, while surface area alterations are more evident in NDSZ. Our findings demonstrate for the first time that DSZ and NDSZ are characterized by different neuroimaging phenotypes, supporting a nosological distinction between DSZ and NDSZ and point toward the separate disease hypothesis.

Trust and psychosis: a systematic review and meta-analysis

BACKGROUND

Impaired trust in other humans is commonly seen in psychosis and it leads to poor societal functioning. However, examining trust behavior in an experimental setting is challenging. Investigators have used the trust game, a neuro-economic game to assess trust behavior in psychosis. However, the findings are inconsistent. Hence, we systematically reviewed the existing literature and conducted a meta-analysis to examine trust behavior in patients with psychosis, their relatives, and those at high risk for psychosis.

METHODS

We searched electronic databases for studies that have examined trust game in patients with psychosis, published up to November 2021. The primary outcome measure was the baseline trust in a trust game by patients and controls. The meta-analysis was performed if at least three data sets of control and patient groups were available for that measure/design. We conducted meta-analyses with a random-effects model. The results were described narratively wherever meta-analysis was not possible due to paucity of studies.

RESULTS

The searches across the databases including cross-references yielded 465 publications of which 10 studies were included in the final analysis. Baseline trust in the trust game was significantly lower in patients with psychosis compared to controls (SMD 0.39, 95% CI -0.14 to 0.64, p -0.002). However, a similar decrease in baseline trust was not present in relatives of patients (SMD 0.08, 95% CI -0.20 to 0.36, p -0.58).

CONCLUSIONS

The current meta-analysis suggests significant trust deficits in patients with psychosis. Future studies with a bigger sample size are required to understand the nature of trust deficits and factors affecting this impairment.

Exploring the Association between Schizophrenia and Cardiovascular Diseases: Insights into the Role of Sigma 1 Receptor

Contemporary society is characterized by rapid changes. Various epidemiological, political and economic crises represent a burden to mental health of nowadays population, which may at least partially explain the increasing incidence of mental disorders, including schizophrenia. Schizophrenia is associated with premature mortality by at least 13-15 years. The leading cause of premature mortality in schizophrenia patients is high incidence of cardiovascular diseases. The specific-cause mortality risk for cardiovascular diseases in schizophrenia patients is more than twice higher as compared to the general population. Several factors are discussed as the factor of cardiovascular diseases development. Intensive efforts to identify possible link between schizophrenia and cardiovascular diseases are made. It seems that sigma 1 receptor may represent such link. By modulation of the activity of several neurotransmitter systems, including dopamine, glutamate, and GABA, sigma 1 receptor might play a role in pathophysiology of schizophrenia. Moreover, significant roles of sigma 1 receptor in cardiovascular system have been repeatedly reported. The detailed role of sigma 1 receptor in both schizophrenia and cardiovascular disorders development however remains unclear. The article presents an overview of current knowledge about the association between schizophrenia and cardiovascular diseases and proposes possible explanations with special emphasis on the role of the sigma 1 receptor.

Lack of correlation between hippocampal substructure atrophy and attention dysfunction in deficit schizophrenia

Hippocampal abnormalities are an established finding in the neuroimaging study of schizophrenia. However, no studies have examined the possibility of regional hippocampal abnormalities specific to deficit schizophrenia (DS) and associations with the unique symptoms of this schizophrenia subtype. This study compared 33 DS and 39 non-deficit schizophrenia (NDS) patients and 38 healthy subjects for hippocampal subfield volumetry. Clinical symptoms were assessed by PANSS, cognition by the neurocognitive battery on the day of the MRI scan. The automatic hippocampal segmentation were preprocesses use FreeSurfer 7.2.0. Unfortunately, the associations between neurocognitive scores and hippocampal subfield volumes in the DS group were not significant after the Bonferroni correction. Our results did not support a causal relationship between hippocampal subregional atrophy and cognitive deficits in DS.

Abnormal Structural Network Communication Reflects Cognitive Deficits in Schizophrenia

Schizophrenia has long been thought to be a disconnection syndrome and several previous studies have reported widespread abnormalities in white matter tracts in individuals with schizophrenia. Furthermore, reductions in structural connectivity may also impair communication between anatomically unconnected pairs of brain regions, potentially impacting global signal traffic in the brain. Therefore, we used different communication models to examine direct and indirect structural connections (polysynaptic) communication in large-scale brain networks in schizophrenia. Diffusion-weighted magnetic resonance imaging scans were acquired from 62 patients diagnosed with schizophrenia and 35 controls. In this study, we used five network communication models including, shortest paths, navigation, diffusion, search information and communicability to examine polysynaptic communication in large-scale brain networks in schizophrenia. We showed less efficient communication between spatially widespread brain regions particulary encompassing cortico-subcortical basal ganglia network in schizophrenia group relative to controls. Then, we also examined whether reduced communication efficiency was related to clinical symptoms in schizophrenia group. Among different measures of communication efficiency, only navigation efficiency was associated with global cognitive impairment across multiple cognitive domains including verbal learning, processing speed, executive functions and working memory, in individuals with schizophrenia. We did not find any association between communication efficiency measures and positive or negative symptoms within the schizophrenia group. Our findings are important for improving our mechanistic understanding of neurobiological process underlying cognitive symptoms in schizophrenia.

Cognitive Dysfunctions Measured with the MCCB in Deficit and Non-Deficit Schizophrenia

This study compared cognitive domains between deficit schizophrenia (DS) and non-deficit schizophrenia (NDS) patients and healthy controls (HC), analyzing relationships between psychopathological dimensions and cognitive domains. A total of 29 DS patients, 45 NDS patients, and 39 HC subjects participated. Cognitive domains were measured using the Measurement and Treatment Research to Improve Cognition in Schizophrenia Battery. Psychopathological symptoms were evaluated with the Positive and Negative Syndrome Scale. Clinical groups performed poorer than HC groups in regards to speed of processing, attention/vigilance, working memory, verbal and visual learning and memory, reasoning and problem solving, and social cognition. DS patients scored poorer than NDS patients in terms of all cognitive domains and the overall score, except for reasoning and problem solving. Positive, negative, disorganization, and resistance symptoms were related to cognitive functions only in NDS patients. Our findings suggest that the MCCB battery is sensitive to detecting cognitive dysfunctions in both deficit and non-deficit schizophrenia.

The Self-Evaluation of Negative Symptoms in Differentiating Deficit Schizophrenia: The Comparison of Sensitivity and Specificity with Other Tools

INTRODUCTION

Psychometric properties of the Self-evaluation of Negative Symptoms (SNS) in subjects with the deficit subtype of schizophrenia (SCZ-D) have not been investigated so far. This study had the following aims: (1) to assess psychometric properties of SNS in subjects with SCZ-D and (2) to explore the usefulness of SNS, in comparison with other clinical characteristics, in screening for SCZ-D.

METHODS

Participants were 82 stable outpatients with schizophrenia, including 40 individuals with SCZ-D and 42 individuals with the non-deficit subtype (SCZ-ND).

RESULTS

Internal consistency was acceptable-to-good in both groups. Factor analysis revealed two dimensions (apathy and emotional). There were significant positive correlations of the SNS total score with the subscore of negative symptoms from the Positive and Negative Syndrome Scale (PANSS) and significant negative correlations with scores of the Social and Occupational Functioning Assessment Scale (SOFAS) in both groups, indicating good convergent validity. The following measures were found to be appropriate screening tools for differentiating SCZ-D and SCZ-ND (p < 0.001): the SNS total score (area under the curve [AUC]: 0.849, cut-off ≥16, sensitivity: 80.0%, specificity: 78.6%), the PANSS subscore of negative symptoms (AUC: 0.868, cut-off ≥11, sensitivity: 90.0%, specificity: 78.6%), and the SOFAS (AUC: 0.779, cut-off ≤59, sensitivity: 69.2%, specificity: 82.5%). Also, adding the SOFAS (cut-off ≤59) to the SNS (cut-off: ≥16) further improved sensitivity and specificity (AUC: 0.898, p < 0.001, sensitivity = 87.5%, specificity = 82.2%). Cognitive performance and age of psychosis onset were not found to be suitable measures for differentiating SCZ-D and SCZ-ND.

CONCLUSION

The present findings indicate that the SNS has good psychometric properties in subjects with SCZ-D and those with SCZ-ND. Moreover, the SNS, the PANSS, and the SOFAS might be used as screening tools for SCZ-D.

Executive Functions and Psychopathology Dimensions in Deficit and Non-Deficit Schizophrenia

This study: (a) compared executive functions between deficit (DS) and non-deficit schizophrenia (NDS) patients and healthy controls (HC), controlling premorbid IQ and level of education; (b) compared executive functions in DS and NDS patients, controlling premorbid IQ and psychopathological symptoms; and (c) estimated relationships between clinical factors, psychopathological symptoms, and executive functions using structural equation modelling. Participants were 29 DS patients, 44 NDS patients, and 39 HC. Executive functions were measured with the Mazes Subtest, Spatial Span Subtest, Letter Number Span Test, Color Trail Test, and Berg Card Sorting Test. Psychopathological symptoms were evaluated with the Positive and Negative Syndrome Scale, Brief Negative Symptom Scale, and Self-evaluation of Negative Symptoms. Compared to HC, both clinical groups performed poorer on cognitive flexibility, DS patients on verbal working memory, and NDS patients on planning. DS and NDS patients did not differ in executive functions, except planning, after controlling premorbid IQ and negative psychopathological symptoms. In DS patients, exacerbation had an effect on verbal working memory and cognitive planning; in NDS patients, positive symptoms had an effect on cognitive flexibility. Both DS and NDS patients presented deficits, affecting the former to a greater extent. Nonetheless, clinical variables appeared to significantly affect these deficits.

Clinical and developmental characteristics of cognitive subgroups in a transdiagnostic sample of schizophrenia spectrum disorders and bipolar disorder

Evidence suggests that neurocognitive dysfunction is a transdiagnostic feature of individuals across the continuum between schizophrenia and bipolar disorder. However, there is significant heterogeneity of neuropsychological and social-cognitive abilities in schizophrenia, schizoaffective disorder, and bipolar disorder. The current study aimed to investigate the clinical and developmental characteristics of cognitive subgroups within the schizo-bipolar spectrum. 147 clinically stable patients with schizophrenia, schizoaffective or bipolar disorder were assessed using clinical rating scales for current psychotic and affective symptoms, and a comprehensive neuropsychological battery including measures of social cognition (Hinting and Reading the mind from the Eyes (RMET) task)). Developmental history and premorbid academic functioning were also evaluated. The study also included 36 healthy controls. Neurocognitive subgroups were investigated using latent class analysis (LCA). The optimal number of clusters was determined based on the Bayesian information criterion. A logistic regression analysis was conducted to investigate the predictors of membership to the globally impaired subgroup. LCA revealed two neurocognitive clusters including globally impaired (n = 89, 60.5%) and near-normal cognitive functioning (n = 58, 39.5%) subgroups. The near-normal cognitive functioning subgroup was not significantly different from healthy controls. The globally impaired subgroup had a higher score of developmental abnormalities (p<0.001), poorer premorbid academic functioning, mothers who were less educated and more severe disorganized speech (p = 0.001) and negative symptoms (p = 0.004) compared to the near-normal cognitive functioning group. History of developmental abnormalities and persistent disorganization rather than diagnosis are significant predictors of the subgroup of individuals with global cognitive impairment in the schizophrenia-bipolar disorder continuum.

Longitudinal changes of cognitive function and its relationship with subdomains of negative symptoms in patients with adult-onset first-episode schizophrenia: A 4-year follow up study

BACKGROUNDS

This study explores the longitudinal changes and trajectories of cognitive functions in patients with adult-onset first-episode schizophrenia (FES) over four years and their relationships with the baseline subdomains of negative symptoms.

METHODS

A total of 177 patients of age 25-55 with FES were recruited. Baseline demographics, clinical, social and cognitive functions were assessed. Diminished expression and diminished motivation of negative symptoms were assessed with Scale for the Assessment of Negative Symptoms (SANS). Patients had yearly follow-up of cognitive function assessments over four years. Latent class growth analysis (LCGA) and mixed linear regression model were used to explore the longitudinal changes of cognitive functions and the effect of baseline negative symptoms on the longitudinal cognitive function changes. Relationships of baseline negative symptoms subdomains and cognitive functions were also explored.

RESULTS

Two trajectories of cognitive functions were identified. Longitudinal improvements were found in most cognitive functions apart from the logical memory. One trajectory of patients had significant deterioration of logical memory while the other group had significant improvement. Baseline diminished expression was associated with baseline and longitudinal changes of processing speed and verbal fluency while diminished motivation was associated with baseline and longitudinal changes of processing speed.

CONCLUSIONS

Adult-onset FES patients had a homogeneous longitudinal improvement in most cognitive functions but not for logical memory suggesting the unique nature of verbal memory. The distinct relationship between baseline subdomains of negative symptoms with baseline and longitudinal cognitive functions suggesting the presence of differential overlapping etiology between negative symptom subdomains and cognitive functions.

The Role of Two Factors of Negative Symptoms and Cognition on Social Functioning in Male Patients with Schizophrenia: A Mediator Model

OBJECTIVE

This study aims to compare the cognitive function and social functioning in male patients with deficit syndrome (DS) and non-DS, and to explore whether cognitive function serves as a mediator in the relationship between the two factors of negative symptoms (motivation and pleasure (MAP) and expressivity (EXP) deficits, and social functioning in schizophrenia patients.

METHODS

One hundred and fifty-six male patients with schizophrenia and 109 age- and education-matched normal controls were enrolled in the current study. The Chinese version of a Schedule for Deficit Syndrome (SDS) was used for DS and non-DS categorization. The Brief Psychiatric Rating Scale (BPRS) and the Brief Negative Symptoms Scale (BNSS) were used to assess psychotic and negative symptoms in patients. The Social-Adaptive Functioning Evaluation (SAFE) was adopted to evaluate patients' social functioning, and a battery of classical neurocognitive tests was used to assess cognition, including sustained vigilance/attention, cognitive flexibility, ideation fluency, and visuospatial memory.

RESULTS

We found that male patients with DS performed worse in all four cognitive domains and social functioning compared to non-DS patients. Both total negative symptoms and its two factors were significantly associated with all four domains of cognition and social functioning in male patients. Interestingly, our results indicate that only cognitive flexibility mediates the relationship between negative symptoms and social functioning in schizophrenia patients, but there were no differences between EXP and MAP negative factors in this model.

CONCLUSION

Our findings suggest that DS patients may represent a unique clinical subgroup of schizophrenia, and the integrated interventions targeting both negative symptoms and cognition, especially cognitive flexibility, may optimally improve functional outcomes in schizophrenia patients.

Association of empathy with clinical symptoms and cognitive function in Chinese chronic schizophrenia patients with and without deficit syndrome

BACKGROUND

Patients with deficit syndrome (DS) are known to experience cognitive impairment. However, there is no consistent conclusion on the impairment of neurocognitive features in DS patients, and no studies have examined their empathy. The purpose of this study was to compare neurocognition and empathy in patients with DS and non-DS schizophrenia.

METHODS

Totally, 665 patients with chronic schizophrenia were enrolled. DS patients were identified by the Proxy Scale for Deficit Syndrome (PDS). Neurocognition and social cognition were assessed by Repeatable Battery for the measurement of Neuropsychological Status (RBANS) and the Interpersonal Reactivity Index (IRI), respectively. In addition, psychopathological symptom severity was assessed by the Positive and Negative Syndrome Scale (PANSS).

RESULTS

Participants included 150 patients with DS and 140 patients with non-DS. DS patients performed significantly worse on the all RBANS domain (except for visuospatial) and total scores as well as IRI scores. Regression analysis showed that PANSS general psychopathology and education were associated with RBANS total score in the DS group (adjusted R² = 0.29), while education and PANSS negative symptoms were correlated with RBANS total score in non-DS patients (adjusted R² = 0.33). In the non-DS group, suicide attempts and PANSS negative symptom score were independently associated with IRI total score (adjusted R² = 0.06), whereas in the DS group, no variable was associated with IRI total score.

CONCLUSIONS

Our findings suggest that patients with DS may have poor neurocognitive and empathy performance. In chronic schizophrenia patients, negative symptoms may play a different role in cognition between DS and non-DS groups.

Current Evidence and Theories in Understanding the Relationship between Cognition and Depression in Childhood and Adolescence: A Narrative Review

The present narrative review has covered the current evidence regarding the role of cognitive impairments during the early phase of major depressive disorder (MDD), attempting to describe the cognitive features in childhood, adolescence and in at-risk individuals. These issues were analyzed considering the trait, scar and state hypotheses of MDD by examining the cold and hot dimensions, the latter explained in relation to the current psychological theoretical models of MDD. This search was performed on several electronic databases up to August 2022. Although the present review is the first to have analyzed both cold and hot cognitive impairments considering the trait, scar and state hypotheses, we found that current evidence did not allow to exclusively confirm the validity of one specific hypothesis since several equivocal and discordant results have been proposed in childhood and adolescence samples. Further studies are needed to better characterize possible cognitive dysfunctions assessing more systematically the impairments of cold, hot and social cognition domains and their possible interaction in a developmental perspective. An increased knowledge on these topics will improve the definition of clinical endophenotypes of enhanced risk to progression to MDD and, to hypothesize preventive and therapeutic strategies to reduce negative influences on psychosocial functioning and well-being.

The percentage and clinical correlates of alexithymia in stable patients with schizophrenia

Alexithymia is a common, but less-recognized affective deficit in patients with schizophrenia. To date, no definitive conclusions have been drawn about the relationship between alexithymia and the clinical symptoms or their clinical correlates, particularly in stable patients with schizophrenia. The purpose of this study was to investigate the link between alexithymia and psychopathological symptoms, as well as any associated correlates, in stable patients with schizophrenia. A total of 435 Chinese patients with schizophrenia were recruited. The Positive and Negative Symptoms Scale (PANSS) was used to evaluate each patient's psychopathological symptoms. The Toronto Alexithymia Scale (TAS-20) was used to measure alexithymia. The percentage of alexithymia was 35.2% in stable patients with schizophrenia. Compared to non-alexithymia patients, patients with alexithymia had higher PANSS total scores, negative subscores, depressive subscores, and cognitive subscores (all p < 0.05). Multivariate regression analysis revealed that the following variables were positively associated with TAS-20 total scores: PANSS negative subscores (β = 0.274, t = 3.198, p = 0.001) and PANSS depressive subscores (β = 0.366, t = 2.500, p = 0.013). Education years (β = - 0.453, t = - 2.824, p = 0.005) was negatively associated with TAS-20 total scores. Our results suggest that the percentage of alexithymia was relatively higher in stable patients with schizophrenia. Education levels, negative symptoms, and depressive symptoms were independently associated with alexithymia in this specific population.

Risk factors of deficit and non-deficit schizophrenia: Results from a cross-sectional study

AIM

It has been observed that deficit and non-deficit schizophrenia (SCZ-D and SCZ-ND) might be characterized by different risk factors. Therefore, the present study aimed to assess as to whether previously reported risk factors of schizophrenia are specifically associated with SCZ-D and SCZ-ND.

METHOD

This study was based on a cohort of 118 stable outpatients with schizophrenia. A diagnosis of SCZ-D was established using the Schedule for the Deficit Syndrome (SDS). Risk factors were recorded using structured interview, the Operational Criteria for Psychotic Illness (OPCRIT) checklist and the Traumatic Experience Checklist (TEC). The following risk factors were explored: male sex, a history of schizophrenia in first-degree relatives, seasonality of birth, birth weight <3000g, delivery by cesarean section, a history of childhood trauma (emotional abuse, emotional neglect, physical abuse and sexual abuse) as well as substance abuse (other than nicotine) and cigarette smoking at psychosis onset.

RESULTS

Individuals with SCZ-D were more likely to be males as well as reported higher rates of birth weight <3000g and any categories of childhood trauma. In turn, substance abuse (other than nicotine) at psychosis onset was significantly more frequent in patients with SCZ-ND. Binary logistic regression, controlling for multiple comparisons, revealed similar findings, except for the association with any categories of childhood trauma that appeared to be not significant.

CONCLUSION

Our findings partially replicate differential patterns of risk factors for SCZ-D (male sex and birth weight <3000g) and SCZ-ND (substance abuse at psychosis onset), likely attributable to the effects of timing of exposure.

Unveiling the Associations between EEG Indices and Cognitive Deficits in Schizophrenia-Spectrum Disorders: A Systematic Review

Cognitive dysfunctions represent a core feature of schizophrenia-spectrum disorders due to their presence throughout different illness stages and their impact on functioning. Abnormalities in electrophysiology (EEG) measures are highly related to these impairments, but the use of EEG indices in clinical practice is still limited. A systematic review of articles using Pubmed, Scopus and PsychINFO was undertaken in November 2021 to provide an overview of the relationships between EEG indices and cognitive impairment in schizophrenia-spectrum disorders. Out of 2433 screened records, 135 studies were included in a qualitative review. Although the results were heterogeneous, some significant correlations were identified. In particular, abnormalities in alpha, theta and gamma activity, as well as in MMN and P300, were associated with impairments in cognitive domains such as attention, working memory, visual and verbal learning and executive functioning during at-risk mental states, early and chronic stages of schizophrenia-spectrum disorders. The review suggests that machine learning approaches together with a careful selection of validated EEG and cognitive indices and characterization of clinical phenotypes might contribute to increase the use of EEG-based measures in clinical settings.

Childhood adversity and psychotic disorders: Epidemiological evidence, theoretical models and clinical considerations

While genetic factors play a critical role in the risk for schizophrenia and other psychotic disorders, increasing evidence points to the role of childhood adversity as one of several environmental factors that can significantly impact the development, manifestations and outcome of these disorders. This paper reviews the epidemiological evidence linking childhood adversity and psychotic disorders and explores various theoretical models that seek to explain the connection. We discuss neurobiological parallels between the impact of childhood trauma and psychosis on the brain and then explore the impact of childhood adversity on different domains of clinical presentation. Finally, implications for prevention and treatment are considered, both on individual and structural levels.

The Impact of Electroconvulsive Therapy on Negative Symptoms in Schizophrenia and Their Association with Clinical Outcomes

OBJECTIVE

The treatment efficacy of electroconvulsive therapy (ECT) for negative symptoms amongst patients with schizophrenia remains unclear. In this study, we aim to examine the effects of ECT on negative symptoms in schizophrenia and their association with other clinical outcomes, including cognition and function.

METHODS

This is a retrospective data analysis of patients with schizophrenia/schizoaffective disorder treated with ECT at the Institute of Mental Health (IMH), Singapore, between January 2016 and December 2019. Clinical outcomes were assessed by the Brief Psychiatric Rating Scale (BPRS), the Montreal Cognitive Assessment (MoCA), and Global Assessment of Function (GAF). Changes in scores were compared with repeated measures analysis of variance. Sequential structural modelling was utilized to examine the pathway relationships between changes in negative symptoms, global functioning, and cognition functioning after ECT.

RESULTS

A total of 340 patients were analysed. Hence, 196 (57.6%), 53 (15.5%), and 91 (26.7%) showed improvements, no change, and deterioration in negative symptoms, respectively. ECT-induced improvement of negative symptoms was significantly associated with improvement of global functioning (direct effect correlation coefficient (r): -0.496; se: 0.152; p = 0.001) and cognition function (indirect effect r: -0.077; se: 0.037; p = 0.035). Moreover, having capacity to consent, more severe baseline negative symptoms, lithium prescription, and an indirect effect of voluntary admission status via consent capacity predicted ECT associated negative symptoms improvement.

CONCLUSION

ECT is generally associated with improvements of negative symptoms in people with schizophrenia, which correlate with improvements of overall function. Possible novel clinical predictors of negative symptom improvement have been identified and will require further research and validation.

The factor structure and clinical utility of clinician-rated dimensions of psychosis symptom severity in patients with recent-onset psychosis: Results of a 1-year longitudinal follow-up prospective cohort study

The classic subtype classification of schizophrenia has been removed, and DSM-5 now includes the Clinician-Rated Dimensions of Psychosis Symptom Severity (CRDPSS). In the present study, a factor analysis of the CRDPSS was performed, and we assessed whether patient classification using the derived factor structure helps predict the clinical course. The participants were 390 patients with recent-onset psychosis enrolled in the Korean Early Psychosis Cohort Study (KEPS). Two factors were identified: psychotic (including delusions, hallucinations, disorganization, and abnormal psychomotor behavior) and negative-cognitive (including negative symptoms and impaired cognition). Patients were grouped based on the factor structure and changes in clinical course were monitored over 1 year. The negative-cognitive group demonstrated longer duration of untreated psychosis, earlier onset, and a higher rate of psychiatric comorbidities. Baseline Positive and Negative Syndrome Scale (PANSS) total and Clinical Global Impression-Severity (CGI-S) scores were higher in psychotic group, but group differences were not observed after 2 months. Conversely, the PANSS negative scale score was significantly higher in negative-cognitive group throughout follow-up, and CGI-S score was reversed at 12 months. The findings indicate that the factor structure derived herein for the CRDPSS could be helpful for predicting the clinical course of recent-onset psychosis patients.

Remote cognitive assessment in severe mental illness: a scoping review

Many individuals living with severe mental illness, such as schizophrenia, present cognitive deficits and reasoning biases negatively impacting clinical and functional trajectories. Remote cognitive assessment presents many opportunities for advancing research and treatment but has yet to be widely used in psychiatric populations. We conducted a scoping review of remote cognitive assessment in severe mental illness to provide an overview of available measures and guide best practices. Overall, 34 studies (n = 20,813 clinical participants) were reviewed and remote measures, psychometrics, facilitators, barriers, and future directions were synthesized using a logic model. We identified 82 measures assessing cognition in severe mental illness across 11 cognitive domains and four device platforms. Remote measures were generally comparable to traditional versions, though psychometric properties were infrequently reported. Facilitators included standardized procedures and wider recruitment, whereas barriers included imprecise measure adaptations, technology inaccessibility, low patient engagement, and poor digital literacy. Our review identified several remote cognitive measures in psychiatry across all cognitive domains. However, there is a need for more rigorous validation of these measures and consideration of potentially influential factors, such as sex and gender. We provide recommendations for conducting remote cognitive assessment in psychiatry and fostering high-quality research using digital technologies.

Serum BDNF levels, glycolipid metabolism in deficit schizophrenia: A case-control study

BACKGROUND

Few studies have compared serum BDNF and glycolipid profiles in patients with deficit schizophrenia (DS) and non-deficit schizophrenia (NDS). We aimed to compare BDNF and glycolipid profiles between DS and NDS patients and healthy controls, and to investigate the relationship between BDNF, glycolipid profiles in DS and NDS patients.

METHODS

A total of 591 patients with chronic schizophrenia (SZ) and 238 healthy controls participated in this study. According to Proxy for the Deficit Syndrome Scale, SZ patients were divided into DS (n = 158) and NDS (n = 273) patients. Psychiatric symptoms were assessed using the Positive and Negative Syndrome Scale (PANSS). Serum BDNF levels were measured using enzyme-linked immunosorbent assay (ELISA).

RESULTS

BDNF levels were significantly lower in SZ patients than those in healthy controls (7.81 ± 2.98 ng/ml vs. 11.96 ± 2.29 ng/ml, P < 0.01). Furthermore, BDNF levels were lower in DS group than those in NDS group (P = 0.007, OR = 0.846, 95% CI = 0.750-0.955). Lower triglyceride levels were also an independent predictor for DS patients (P = 0.007, OR = 0.846, 95% CI = 0.750-0.955). Serum BDNF levels were negatively associated with the severity of deficit syndrome in SZ patients (β = -1.151, t = -2.559, P = 0.011). In DS group, triglycerides were associated with PANSS negative subscore (β = -0.262, t = -2.994, P = 0.003) and depressive factor subscore (β = 0.282, t = 2.146, P = 0.035).

CONCLUSION

Serum BDNF and triglycerides may be informative biomarkers of DS in SZ patients. The differences in glycolipid metabolism patterns between DS and NDS patients indicate that deficit syndrome is an independent endophenotype of SZ patients.

From Memories of Past Experiences to Present Motivation? A Meta-analysis on the Association Between Episodic Memory and Negative Symptoms in People With Psychosis

Based on findings from cognitive science, it has been theorized that the reductions in motivation and goal-directed behavior in people with psychosis could stem from impaired episodic memory. In the current meta-analysis, we investigated this putative functional link between episodic memory deficits and negative symptoms. We hypothesized that episodic memory deficits in psychosis would be related to negative symptoms in general but would be more strongly related to amotivation than to reduced expressivity. We included 103 eligible studies (13,622 participants) in the analyses. Results revealed significant, moderate negative associations of episodic memory with negative symptoms in general (k = 103; r = -.23; z = -13.40; P ≤ .001; 95% CI [-.26; -.20]), with amotivation (k = 16; r = -.18; z = -6.6; P ≤ .001; 95% CI [-.23; -.13]) and with reduced expressivity (k = 15; r = -.18; z = -3.30; P ≤.001; 95% CI[-.29; -.07]). These associations were not moderated by sociodemographic characteristics, positive symptoms, depression, antipsychotic medication or type of negative symptom scale. Although these findings provide sound evidence for the association between episodic memory deficits and amotivation, the rather small magnitude and the unspecific pattern of this relationship also indicate that episodic memory deficits are unlikely to be the only factor relevant to amotivation. This implicates that future research should investigate episodic memory in conjunction with other factors that could account for the association of episodic memory deficits and amotivation in psychosis.

Subjectively-assessed cognitive impairment and neurocognition associations in schizophrenia inpatients

Cognitive impairment affects real-world functioning in people with schizophrenia who often face difficulties in their activities of daily living. Subjectively-assessed cognitive impairment can be evaluated through data on the patient's daily difficulties, as reported by the patient. However, the specific neurocognitive functions responsible for these cognitive impairments have not been clarified. We examined cognitive functioning in patients with schizophrenia using the Schizophrenia Cognition Rating Scale Japanese version (SCoRS-J) and the Brief Assessment of Cognition in Schizophrenia Japanese version (BACS-J). This study aimed to investigate the relationship between subjectively-assessed cognitive impairment and objectively assessed neurocognition in patients with schizophrenia. The results showed that patients' global rating scores of the SCoRS-J were significantly correlated with the BACS-J attention scores (r = −0.376, p < 0.008), which indicates that the difficulties patients perceived in their daily lives are due to deficits in attentional functioning, as measured by neurocognitive testing. Thus, our findings indicate that improving attentional functioning may also alleviate difficulties in patients' daily lives.

Neuropsychological differences between treatment-resistant and treatment-responsive schizophrenia: a meta-analysis

Antipsychotic treatment resistance affects up to a third of individuals with schizophrenia. Of those affected, 70-84% are reported to be treatment resistant from the outset. This raises the possibility that the neurobiological mechanisms of treatment resistance emerge before the onset of psychosis and have a neurodevelopmental origin. Neuropsychological investigations can offer important insights into the nature, origin and pathophysiology of treatment-resistant schizophrenia (TRS), but methodological limitations in a still emergent field of research have obscured the neuropsychological discriminability of TRS. We report on the first systematic review and meta-analysis to investigate neuropsychological differences between TRS patients and treatment-responsive controls across 17 published studies (1864 participants). Five meta-analyses were performed in relation to (1) executive function, (2) general cognitive function, (3) attention, working memory and processing speed, (4) verbal memory and learning, and (5) visual-spatial memory and learning. Small-to-moderate effect sizes emerged for all domains. Similarly to previous comparisons between unselected, drug-naïve and first-episode schizophrenia samples v. healthy controls in the literature, the largest effect size was observed in verbal memory and learning [dl = -0.53; 95% confidence interval (CI) -0.29 to -0.76; z = 4.42; p < 0.001]. A sub-analysis of language-related functions, extracted from across the primary domains, yielded a comparable effect size (dl = -0.53, 95% CI -0.82 to -0.23; z = 3.45; p < 0.001). Manipulating our sampling strategy to include or exclude samples selected for clozapine response did not affect the pattern of findings. Our findings are discussed in relation to possible aetiological contributions to TRS.

Eye movement characteristics in male patients with deficit and non-deficit schizophrenia and their relationships with psychiatric symptoms and cognitive function

BACKGROUND

The cognitive impairment pattern of deficit schizophrenia (DS) is centered on an impaired attention function. Previous studies have suggested that the exploratory eye movement (EEM) tests reflect attention deficits in patients with schizophrenia. However, no study has investigated the characteristics of eye movement in DS in the Chinese Han population. This study aimed to investigate the pattern of eye movement characteristics in DS patients and to examine whether eye movement characteristic is associated with serious negative symptoms and cognitive decline in this schizophrenia subtype.

METHODS

A total of 86 male patients [37 DS and 49 non-deficit schizophrenia (NDS)] and 80 healthy controls (HC) participated in this study. Clinical symptoms were assessed using the Scale for the Assessment of Positive Symptoms (SAPS) and Scale for the Assessment of Negative Symptoms (SANS). Cognitive function was assessed using the Mattis Dementia Rating Scale (MDRS-2). Eye movement data of subjects were collected using an eye movement tracking analyzer.

RESULTS

There were significant differences in the overall eye movement data and cognitive test scores among the three groups (all P < 0.001). Both DS and NDS schizophrenia subgroups showed more severe eye movement and cognitive impairment compared with the control group. The number of eye fixations (NEF), total of eye scanning length (TESL), and cognitive function in DS patients were significantly lower than those in NDS patients. The discriminant analysis (D score) was higher than that of the control group (P < 0.001). In the DS group, the inattention factor of SANS was negatively correlated with the attention factor (r = - 0.545, P = 0.001) and structure factor of cognitive (r = - 0.389, P = 0.023), the affective flattening factor of SANS was negatively correlated with TESL (r = - 0.353, P = 0.041) and initiation/retention factor of cognitive (r = - 0.376,P = 0.028). TESL was found to positively correlate with the MDRS-2 total score (r = 0.427, P = 0.012), attention factor (r = 0.354, P = 0.040), and memory factor (r = 0.349, P = 0.043) in the DS group, whereas the mean of eye scanning length (MESL) positively correlated with cognitive impairments in the NDS group. The negative symptoms showed no significant correlation with cognition in the NDS group.

CONCLUSIONS

Total of eye scanning length may be a characteristic eye movement symptom in DS patients, which is associated with serious negative symptoms and cognitive impairment in this schizophrenia subtype.

Understanding others as a mediator between verbal memory and negative symptoms in schizophrenia-spectrum disorder

From the onset of schizophrenia, verbal memory (VM) deficits and negative symptoms are strongly associated, and both additively predict functional outcomes. Emotion recognition (ER) and theory of mind (ToM; the ability to infer others' mental states), two components of social cognition, are also particularly affected in schizophrenia. Explanatory models of negative symptoms have integrated these cognitive impairments as potential precursors and previous studies revealed relationships between ER and/or ToM and VM, as well as with negative symptoms, but the organization of these associations remains unclear. We aimed to determine whether impairments in VM and social cognition sequentially pave the way for negative symptoms in schizophrenia. To this end, we used mediation analyses. One hundred and forty participants with a diagnosis of schizophrenia or schizoaffective disorder were recruited. First, correlational analyses were conducted between our variables of interest. The mediating effect of social cognition between VM and negative symptoms was then examined using the PROCESS macro. Variables of interest were significantly correlated (r = |0.166| to |0.391|), except for ER and negative symptoms. Only the serial multiple mediation model with 2 mediators (ER followed by ToM) revealed a significant indirect effect of VM on negative symptoms (β = - 0.160, 95% CI = -.370 to -.004). This relationship was selective for expressive negative symptoms (e.g., blunted affect and alogia). This study illustrates the richness of the relationship between cognitive deficits and negative symptoms and provides additional information for the involvement of social cognition in negative symptoms' etiology.

Deficit syndrome in Chinese patients with first-episode drug naïve schizophrenia: Prevalence, demographic and clinical characteristics

BACKGROUND

Deficit syndrome (DS) is a common subgroup of schizophrenia. However, few studies have examined the prevalence and risk factors for DS in Chinese Han patients with schizophrenia. The aim of this study was to assess prevalence, demographic and clinical characteristics of DS in Chinese Han patients with first-episode drug naïve (FEDN) schizophrenia.

METHODS

In total, 235 patients with schizophrenia were recruited, and clinical and demographic data were collected. The Positive and Negative Syndrome Scale (PANSS) was utilized for the psychopathological symptoms, and the 17-item Hamilton Depression Rating Scale (HDRS-17) for depressive symptoms. The Proxy for the Deficit Syndrome (PDS) was adopted to identify DS.

RESULTS

The prevalence of DS in the cohort of first-episode schizophrenia patients was 23.0%. Compared to those patients without DS, patients with DS had younger age, lower education level, and were more likely to be single. Further, DS patients had significantly lower scores of positive symptoms, general psychopathology, and depression than non-DS patients. Patients with DS had fewer suicide attempts, but they had more severe negative symptoms and cognitive impairment (all p < 0.05). Multiple regression showed that poor cognitive functioning, lower levels of depression and younger age at onset were predictors of DS.

CONCLUSIONS

Chinese Han patients with FEDN schizophrenia have high prevalence of DS. Some demographic and clinical parameters may be associated with DS.

Decreased neuregulin1β1 in first episode and drug-naïve patients with schizophrenia: Negative correlation with cognitive impairment

BACKGROUND

Neuregulin1β1 (NRG1β1) is essential for neuronal migration during development and for the ongoing neural plasticity underlying cognitive function. This study investigated the relationship between cognitive impairment and serum NRG1β1 concentration in first-episode drug-naïve (FEDN) patients with schizophrenia.

METHOD

We measured serum NRG1β1 from 65 FEDN schizophrenia patients and 67 healthy matched controls. Cognitive function was evaluated using the Hopkins Vocabulary Learning Test-Revised (HVLT-R), Verbal Fluency Test (VFT), Trail Making Test (TMT), Digit Span Test (DST), and Stroop Test.

RESULTS

Serum NRG1β1 concentration was significantly lower in the FEDN patient group than the control group (7.25±0.49 vs. 12.52±0.77 ng/mL; F=23.716, P<0.0001, Cohen's d=1.00). Further, serum NRG1β1 concentration in FEDN schizophrenia patients was negatively correlated with TMT-part A score (r=-0.408, P=0.001) and positively correlated with Stroop color subtest score (r=0.246, P=0.048). Multiple regression analysis also revealed weak correlations among FEDN patients between TMT-part A score and both serum NRG1β1 concentration (R²=0.116, F=8.235, P=0.011) and duration of untreated psychosis (R²=0.193, F=5.969, P=0.017).

CONCLUSION

This preliminary study suggests that serum NRG1β1 levels are reduced in FEDN patients with schizophrenia and that NRG1β1 may be involved in the cognitive function.

Decision Making under Risk in Patients Suffering from Schizophrenia or Depression

Studies have reported difficulties in decision making for patients with schizophrenia or depression. Here, we investigated whether there are differences between schizophrenia patients, depressed patients, and healthy individuals (HC) when decisions are to be made under risk and cognitive flexibility is required. We were also interested in the relationships between decision making, cognitive functioning, and disease severity. Thirty HC, 28 schizophrenia patients, and 28 depressed patients underwent structured clinical assessments and were assessed by the Positive and Negative Syndrome Scale or Hamilton Rating Scale. They performed the Probability-Associated Gambling (PAG) Task and a neuropsychological test battery. Both patient groups obtained lower scores than HC in memory and executive function measures. In the PAG task, relative to HC, depressed patients made slower decisions but showed a comparable number of advantageous decisions or strategy flexibility. Schizophrenia patients were slower, riskier, and less flexible compared to HC. For them, the decision making behavior correlated with the symptom severity. In both groups, decision making scores correlated with memory and executive function scores. Patients with schizophrenia or depression may have difficulties under risk when quick and flexible decisions are required. These difficulties may be more pronounced in patients who have marked cognitive deficits or severe clinical symptoms.