Cognitive Deficits in Schizophrenia: Understanding the Biological Correlates and Remediation Strategies

Genetic analysis of psychosis Biotypes: shared Ancestry-adjusted polygenic risk and unique genomic associations

The Bipolar-Schizophrenia Network for Intermediate Phenotypes (B-SNIP) created psychosis Biotypes based on neurobiological measurements in a multi-ancestry sample. These Biotypes cut across DSM diagnoses of schizophrenia, schizoaffective disorder, and bipolar disorder with psychosis. Two recently developed post hoc ancestry adjustment methods of Polygenic Risk Scores (PRSs) generate Ancestry-Adjusted PRSs (AAPRSs), which allow for PRS analysis of multi-ancestry samples. Applied to schizophrenia PRS, we found the Khera AAPRS method to show superior portability and comparable prediction accuracy as compared with the Ge method. The three Biotypes of psychosis disorders had similar AAPRSs across ancestries. In genomic analysis of Biotypes, 12 genes, and isoforms showed significant genomic associations with specific Biotypes in a Transcriptome-Wide Association Study (TWAS) of genetically regulated expression (GReX) in the adult brain and fetal brain. TWAS inflation was addressed by the inclusion of genotype principal components in the association analyses. Seven of these 12 genes/isoforms satisfied Mendelian Randomization (MR) criteria for putative causality, including four genes TMEM140, ARTN, C1orf115, CYREN, and three transcripts ENSG00000272941, ENSG00000257176, ENSG00000287733. These genes are enriched in the biological pathways of Rearranged during Transfection (RET) signaling, Neural Cell Adhesion Molecule 1 (NCAM1) interactions, and NCAM signaling for neurite out-growth. The specific associations with Biotypes suggest that pharmacological clinical trials and biological investigations might benefit from analyzing Biotypes separately.

Cognitive Remediation Is an Evidence-Based Psychological Therapy: Isn't It Time It Was Treated Like One?

Cognitive remediation (CR) is an evidenced-based intervention, but is not consistently included in clinical guidelines, nor implemented widely in mental health services, and is still not fully accepted as a psychological therapy. This is despite demonstrating a boost to recovery, and reductions in health care costs. We describe potential issues as CR matures into a widely accepted and used psychological therapy by drawing on high-quality evidence from reviews and meta-analyses and specifically highlight how CR uses therapeutic formulation, similar to other psychological therapies, to address specific client needs. Most evidence is for those with a diagnosis of schizophrenia, but we also consider CR benefits for other mental health conditions. Data emerging from different health systems are, at last, providing information on how CR is used, disseminated and practice standards maintained. This may be the information needed to support further implementation, expansion, and consolidation of CR use globally.

Cognitive symptoms in schizophrenia: an analysis of awareness, assessment, and management practices among psychiatrists and primary care physicians

Introduction

Cognitive symptoms contribute to the worsening of functionality in people with schizophrenia. The objective of this study was to explore the current knowledge about cognitive symptoms (relevance, evaluation, and management) of psychiatrists and primary care physicians (PCPs) involved in the care of patients with schizophrenia in Spain.

Methods

The study was developed in two phases: a quantitative phase and a qualitative one. Both took place between November 2023 and January 2024. For the quantitative phase, an online questionnaire was developed and administered to 100 psychiatrists and 125 PCPs. In addition, further qualitative data were collected through individual semi-structured telephone interviews. Descriptive analyses and qualitative analyses (induction-deduction approach) were carried out.

Results

Health professionals agreed that cognitive symptoms are present in patients with schizophrenia, with 75% of psychiatrists and 45% of PCPs acknowledging this. Both groups also considered the detection of these symptoms as crucial for improving patient functionality (89% psychiatrists vs 88% PCPs). However, over half of both psychiatrists and PCPs do not consistently evaluate cognitive symptoms, attributing this to factors such as time constraints, limited access to both pharmacological and non-pharmacological treatments, and a lack of effective diagnostic tools. PCPs additionally highlighted insufficient training regarding cognitive symptoms in schizophrenia. Both groups underscored the need for specific treatments for cognitive symptoms, with 87% agreement.

Conclusion

This study offers an overview of the current understanding regarding the relevance, evaluation, and management of various cognitive symptoms according to clinical practice in Spain. The results highlight the necessity for enhanced guidelines, training, and improved access to effective treatments to address cognitive symptoms in patients with schizophrenia.

Suicidal risk in patients with aggression in schizophrenia: a systematic review

Introduction

Suicide represents the primary risk factor for mortality among individuals diagnosed with schizophrenia, with a mortality rate that is 10 times higher than that observed in the general population. In the study of individuals who have committed suicide, some exhibited a high risk of aggression and impulsivity, which permitted the consideration of these indicators as predictors of suicide risk. The extant literature contains a number of debates concerning diverse conceptualizations of aggression and impulsivity in the context of suicidal behavior. The present study examined the levels of verbal and physical aggression in individuals diagnosed with schizophrenia, finding that 43% exhibited verbal aggression and 24% physical aggression, levels that are significantly higher than those observed in the general population. Concurrently, an analysis of the psycho-emotional state of patients with suicidal behavior in the anamnesis reveals an indication that the suppression of emotions (including aggression) and the avoidance of harm may result in suicide. This finding is at odds with the previously mentioned results, and consequently, the present review sought to assess the impact of aggressive behavior on suicide risk in patients diagnosed with schizophrenia.

Methods

The search was conducted in accordance with the Preferred Reporting Items for Systematic Reviews and Meta-Analyses (PRISMA) statement. The literature search was conducted in PubMed, Cochrane Library, PsychINFO and Mendeley Data. The search terms used were "aggress*" and "suicid*" or "autoaggress*" and "schizophrenia*". The search was limited to papers published between 2009 and 2024 (the last 15 years), and the search was continued until November 2024. This systematic review has been registered in PROSPERO (CRD42024628033).

Results

A total of 1,364 articles were identified, 295 of which were duplicates. Following a thorough review, 1,046 articles that did not align with the title and abstract were excluded from the analysis. During the literature search, 23 articles were read in full, of which eight studies met the inclusion criteria. A total of eight studies provided information on the effect of aggressive behavior on suicide in patients with schizophrenia. Of these, six studies demonstrated a positive association between aggression and suicidal behavior or employed a logistic regression model in which the risk of aggression increased the risk of suicide and vice versa. Conversely, two studies revealed no association between suicide risk and aggression.

Conclusions

Patients with a documented history of suicide attempts and aggressive behavior are considered to be at risk of suicide, thus emphasizing the necessity for preventive measures to be implemented for this cohort of patients. However, the conclusion regarding the influence of aggressive behavior on increased suicide risk may not be entirely accurate and may not reflect the true extent of the problem, due to the significant number of methodological inaccuracies and discrepancies in the design of the studies included in the review.

Systematic review registration

https://www.crd.york.ac.uk/PROSPERO/view/CRD42024628033, identifier CRD42024628033.

Volumetric Changes in Cerebellar Transverse Zones: Age and Sex Effects in Health and Neurological Disorders

Cerebellar volumetric changes are intricately linked to aging, with distinct patterns across its transverse zones, the functional subdivisions characterized by unique cytoarchitectural and connectivity profiles. Despite research efforts, the cerebellar aging process in health and neurological disorders remains poorly understood. In this study, we investigated the effects of age and sex on total cerebellum, transverse zone, and lobule volumes using MRI data from over 45,000 participants compiled from six neuroimaging datasets. We also propose a framework for estimating cerebellum age as an indicator of cerebellar health. Significant age-dependent volume reductions were observed across transverse zones, with the central zone (CZ; lobules VI and VII) exhibiting the steepest decline in both health and neurological disorders. This finding highlights the CZ's vulnerability to aging and its critical role in cognitive and emotional processing. We also found prominent sex differences in age-dependent volumetric changes. Males exhibited smaller total intracranial volume (TIV)-adjusted cerebellum volume and faster age-dependent volume reduction than females in both health and mild cognitive impairment (MCI), Alzheimer disease (AD), and Parkinson disease (PD). In contrast, females with schizophrenia (SZ) and cocaine use disorder (CUD) revealed faster age-dependent cerebellar volume reduction than males. Patients with MCI, AD, and PD experienced more pronounced atrophy in the posterior (PZ) and nodular (NZ) zones compared to age-matched healthy controls, while SZ patients were characterized by a more prominent reduction in CZ. In CUD, a non-significant volume decline was observed in all zones compared to the controls. Moreover, our framework for estimating cerebellum age revealed a notable difference in cerebellar aging between healthy individuals and neurological patients. Finally, we charted age-dependent changes in cerebellar volume in healthy individuals, focusing on transverse zones capturing the functional subdivisions. These findings underscore the potential of cerebellar volumetric analysis as a biomarker for early detection and monitoring of neurodegenerative and neuropsychiatric disorders. Our novel approach complements and enhances MRI-based analyses, providing essential insights into the pathogenesis of aging, neurodegeneration, and chronic neuropsychiatric conditions.

The Mediating Role of Internalized Stigma and Illness Knowledge in the Relationship Between Psychological Flexibility and Symptom Severity in Schizophrenia

Schizophrenia is a chronic mental illness that affects daily functioning and quality of life. Many patients experience internalized stigma, which worsens symptoms and quality of life. Psychological flexibility may help reduce stigma's negative effects. This study explores how psychological flexibility, internalized stigma, and illness knowledge relate to symptom severity in schizophrenia. We hypothesized that internalized stigma mediates the link between psychological flexibility and symptoms, and that greater illness knowledge leads to lower stigma and better outcomes. This cross-sectional study included patients diagnosed with schizophrenia at a Community Mental Health Center (CMHC) in Turkey. 253 participants completed standardized scales of psychological flexibility(AAQ-II), internalized stigma(ISMI), knowledge about schizophrenia(KASQ), and symptom severity(PANSS). Mediation analysis was performed using the PROCESS macro for SPSS to assess the indirect effects of stigma and illness knowledge on symptom severity. Psychological flexibility was significantly associated with lower levels of internalized stigma (β = -1.046, p < 0.001). Internalized stigma mediated the relationship between psychological flexibility and symptom severity(β = 0.506, p < 0.001), whereas illness knowledge had a protective effect on symptom severity(β = -1.582, p < 0.001). However, illness knowledge did not significantly mediate the relationship between psychological flexibility and stigma. The findings highlight the critical role of psychological flexibility in mitigating the negative impact of internalized stigma, suggesting that interventions aimed at enhancing flexibility could improve clinical outcomes. Psychoeducation programs may further reduce symtom severity by increasing ilness knowledge. Future research should explore longitudinal interventions targeting stigma reduction and psychological flexibility to enhance functional recovery in schizophrenia.

Evidence for shallow cognitive maps in Schizophrenia

Individuals with schizophrenia can have marked deficits in goal-directed decision making. Prominent theories differ in whether schizophrenia (SZ) affects the ability to exert cognitive control or the motivation to exert control. An alternative explanation is that schizophrenia negatively impacts the formation of cognitive maps, the internal representations of the way the world is structured, necessary for the formation of effective action plans. That is, deficits in decision-making could arise when goal-directed control and motivation are intact but used to plan over ill-formed maps. We tested the hypothesis that individuals with SZ are impaired in constructing cognitive maps. We combine a behavioral representational similarity analysis technique with a sequential decision-making task. This enables us to examine how relationships between choice options change when individuals with SZ and healthy age-matched controls build a cognitive map of the task structure. Our results indicate that SZ affects how people represent the structure of the task, focusing more on simpler visual features and less on abstract, higher-order, planning-relevant features. At the same time, we find that individuals with SZ were able to display similar performance on this task compared with controls, emphasizing the need for a distinction between cognitive map formation and changes in goal-directed control in understanding cognitive deficits in schizophrenia.

The Balance in the Head: How Developmental Factors Explain Relationships Between Brain Asymmetries and Mental Diseases

Cerebral lateralisation is a core organising principle of the brain that is characterised by a complex pattern of hemispheric specialisations and interhemispheric interactions. In various mental disorders, functional and/or structural hemispheric asymmetries are changed compared to healthy controls, and these alterations may contribute to the primary symptoms and cognitive impairments of a specific disorder. Since multiple genetic and epigenetic factors influence both the pathogenesis of mental illness and the development of brain asymmetries, it is likely that the neural developmental pathways overlap or are even causally intertwined, although the timing, magnitude, and direction of interactions may vary depending on the specific disorder. However, the underlying developmental steps and neuronal mechanisms are still unclear. In this review article, we briefly summarise what we know about structural, functional, and developmental relationships and outline hypothetical connections, which could be investigated in appropriate animal models. Altered cerebral asymmetries may causally contribute to the development of the structural and/or functional features of a disorder, as neural mechanisms that trigger neuropathogenesis are embedded in the asymmetrical organisation of the developing brain. Therefore, the occurrence and severity of impairments in neural processing and cognition probably cannot be understood independently of the development of the lateralised organisation of intra- and interhemispheric neuronal networks. Conversely, impaired cellular processes can also hinder favourable asymmetry development and lead to cognitive deficits in particular.

Deviant sound frequency and time stimuli in auditory oddball tasks reveal persistent aberrant brain activity in patients with psychosis and symptomatic remission

The detection of rare or deviant stimuli shares common brain circuits involved in temporal processing and salience, critical for cognitive control. Disruption in these processes may contribute to the mechanisms of the disease and explain cognitive deficits observed in psychosis and related disorders. We designed a neuroimaging study, using oddball task-based functional sequences (fMRI) and diffusion tensor imaging (DTI), comparing healthy controls (HC, n = 14, 7 females) and patients with stable psychosis (PSY, n = 20, 10 females). The PSY individuals had schizophrenia or bipolar disorder diagnosis (ICD-10), meeting symptom remission criteria in the last 6 months. Two variants of the auditory oddball paradigm were employed, focusing on sound frequency (SF) and time discrimination (TD) tasks, adapted for fMRI. We used a general linear model to analyze fMRI data and a random effects model for group analysis, complemented by an exploratory statistical agnostic mapping analysis. DTI data were processed using FSL (FMRIB Software Library) and TBSS (Tract Based Spatial Statistics). Distinct activation patterns between groups were observed, with increased brain activity in PSY in TD and SF oddball tasks. In response to increased task difficulty, HC predominantly activated cerebellar regions, whereas PSY relied more on frontal regions. Reduced fractional anisotropy in PSY correlated with lower performance scores in the MATRICS (Measurement and Treatment Research to Improve Cognition in Schizophrenia) Consensus Cognitive Battery (MCCB). The study underscores aberrant brain activity and white matter deficits in stable psychosis patients, highlighting distinct responses to cognitive challenges compared to HC. These findings may support the hypothesis of cognitive dysmetria as a potential underlying mechanism in psychosis and highlight future therapeutic strategies, including non-invasive brain stimulation techniques.

Associations between cytokine levels and cognitive function among individuals at clinical high risk for psychosis

OBJECTIVE

To explore the intricate interplay among cytokines, cognitive functioning, and conversion to psychosis in individuals at clinical high-risk (CHR) for psychosis.

METHOD

We initially enrolled 385 individuals at CHR and 95 healthy controls (HCs). Subsequently, 102 participants at CHR completed the 1-year follow-up assessments, and 47 participants transitioned to psychosis. We assessed the levels of interleukins (IL-1β, IL-2, IL-6, IL-8, IL-10), tumor necrosis factor-α (TNF-α), granulocyte-macrophage colony-stimulating factor (GM-CSF), and vascular endothelial growth factor (VEGF). We comprehensively evaluated cognitive performance across six domains, including speed of processing (SP), attention/vigilance (AV), working memory (WM), verbal learning (VeL), visual learning (ViL), and reasoning and problem-solving (RPS).

RESULTS

Higher baseline cognitive domain scores were associated with elevated GM-CSF and reduced VEGF levels. In the follow-up analysis, significant time effects were observed for IL-1β and IL-2. We also observed significant interaction effects between specific cognitive domains (AV, WM, VeL, and OCS) and levels of cytokine (GM-CSF, IL-1β, IL-6, and TNF-α). Changes in WM were negatively correlated with changes in TNF-α levels and positively correlated with changes in VEGF levels. Variations in VeL were inversely correlated with changes in GM-CSF and IL-10 levels, whereas changes in RPS were positively associated with changes in GM-CSF and IL-8 levels.

CONCLUSIONS

Our results revealed intricate associations among cytokine levels, cognitive performance, and psychosis progression.

Exploring Cognitive Deficits and Neuromodulation in Schizophrenia: A Narrative Review

Cognitive deficits are emerging as critical targets for managing schizophrenia and enhancing clinical and functional outcomes. These deficits are pervasive among individuals with schizophrenia, affecting various cognitive domains. Traditional pharmacotherapy and cognitive behavioral therapy (CBT) have limitations in effectively addressing cognitive impairments in this population. Neuromodulation techniques show promise in improving certain cognitive domains among patients with schizophrenia spectrum disorders. Understanding the mechanisms of neural circuits that underlie cognitive enhancement is essential for elucidating the pathophysiological processes of the disorder, and these insights could significantly optimize strategies for managing schizophrenia. Meanwhile, although there is an increasing body of evidence demonstrating the therapeutic effects of neuromodulation in this area, further research is still needed, particularly regarding topics such as different treatment protocols and the long-term effects of treatment.

Genetic Analysis of Psychosis Biotypes: Shared Ancestry-Adjusted Polygenic Risk and Unique Genomic Associations

The Bipolar-Schizophrenia Network for Intermediate Phenotypes (B-SNIP) created psychosis Biotypes based on neurobiological measurements in a multi-ancestry sample. These Biotypes cut across DSM diagnoses of schizophrenia, schizoaffective disorder and bipolar disorder with psychosis. Two recently developed post hoc ancestry adjustment methods of Polygenic Risk Scores (PRSs) generate Ancestry-Adjusted PRSs (AAPRSs), which allow for PRS analysis of multi-ancestry samples. Applied to schizophrenia PRS, we found the Khera AAPRS method to show superior portability and comparable prediction accuracy as compared with the Ge method. The three Biotypes of psychosis disorders had similar AAPRSs across ancestries. In genomic analysis of Biotypes, 12 genes and isoforms showed significant genomic associations with specific Biotypes in Transcriptome-Wide Association Study (TWAS) of genetically regulated expression (GReX) in adult brain and fetal brain. TWAS inflation was addressed by inclusion of genotype principal components in the association analyses. Seven of these 12 genes/isoforms satisfied Mendelian Randomization (MR) criteria for putative causality, including four genes TMEM140, ARTN, C1orf115, CYREN, and three transcripts ENSG00000272941, ENSG00000257176, ENSG00000287733. These genes are enriched in the biological pathways of Rearranged during Transfection (RET) signaling, Neural Cell Adhesion Molecule 1 (NCAM1) interactions, and NCAM signaling for neurite out-growth. The specific associations with Biotypes suggest that pharmacological clinical trials and biological investigations might benefit from analyzing Biotypes separately.

THPP-1 PDE10A inhibitor reverses the cognitive deficits and hyperdopaminergic state in a neurodevelopment model of schizophrenia

Schizophrenia (SCZ) is a complex neuropsychiatric disorder characterized by positive, negative, and cognitive symptoms. The neurodevelopmental methylazoxy-methanol acetate (MAM) rodent model replicates key neurobiological features of SCZ which includes hyperdopaminergic states in the ventral tegmental area (VTA) and cognitive deficits. Typical and atypical antipsychotics are primarily effective in treating the positive symptoms of SCZ but often fall short of addressing cognitive deficits. A promising therapeutic approach for treating all symptoms of SCZ has emerged through the inhibition of phosphodiesterase 10 A (PDE10A). Our study aim was to investigate the impact of acute and chronic THPP-1 (PDE10A inhibitor) treatment, in MAM rats, focusing on cognitive deficits and VTA dopamine (DA) activity. Adult offspring of pregnant rats treated with Saline or MAM (20 mg/kg) on gestational day 17 were treated with THPP-1 acutely (male/female rats; 3 mg/kg) at postnatal day (PD) 70-80 or chronically (males; 3 weeks; 2-3 mg/kg) from PD 70-91 and tested in the novel object recognition test and electrophysiological recording of DA neurons in the VTA. Acute THPP-1 treatment reversed cognitive impairments and normalized the increased number of active DA neurons in the VTA of male and female MAM rats, without affecting control rats. Also, chronic THPP-1 treatment reversed cognitive deficits and normalized DA hyperactivity in the VTA of male MAM rats. The efficacy of THPP-1 in reversing MAM-induced impairments underscores its ability to target disease-specific circuitry without affecting normal regulated systems in control rats. Our findings highlight the therapeutic potential of THPP-1 for addressing cognitive deficits and DA dysregulation in SCZ.

Psychiatric and functional correlates of stigma associated with cognitive impairment in schizophrenia

Schizophrenia is the most strongly stigmatized psychiatric diagnosis, with negative stereotypes including assumptions of incompetence and inability to recover. Individuals with cognitive impairment associated with schizophrenia (CIAS) have reported stigma experiences, suggesting that CIAS carries stigma in addition to the stigma associated with schizophrenia as a diagnostic label. While research has established that mental illness stigma more generally is linked with poor psychiatric and functional outcomes, no research has explored correlates of CIAS stigma. This study evaluated cognitive, psychiatric, and functional correlates of CIAS stigma among 54 individuals with schizophrenia spectrum disorders participating in a cognitive remediation trial. Participants with greater estimated cognitive decline reported higher levels of CIAS stigma experiences. Participants who reported higher levels of CIAS stigma also scored higher on a measure of depressive symptom severity. No significant associations were found between CIAS stigma and positive and negative psychosis symptoms or general psychopathology ratings. CIAS stigma was not associated with performance-based functional capacity or ratings of community functioning. Findings suggest that CIAS stigma is linked with the degree of cognitive decline and depressive symptom severity among individuals with schizophrenia spectrum disorders. Additional research is needed to elucidate directionality and the relationship between CIAS stigma and functioning outcomes.

Association between cognitive functioning, suicidal ideation and suicide attempts in major depressive disorder, bipolar disorder, schizophrenia and related disorders: A systematic review and meta-analysis

INTRODUCTION

Treatable mental disorders, such as psychotic, major depressive disorder (MDD), and bipolar disorder (BD), contribute to a substantial portion of suicide risk, often accompanied by neurocognitive deficits. We report the association between cognitive function and suicidal ideation/suicide attempts (SI/SA) in individuals with schizoaffective disorder, BD, and MDD.

METHODS

A systematic search was conducted on PubMed, Ovid and Scopus databases for primary studies published from inception to April 2024. Eligible articles that reported on the effect size of association between cognition and SI/SA were pooled using a random effects model.

RESULTS

A total of 41 studies were included for analysis. There was a negative association between executive functioning and SI/SA in schizoaffective disorder (SA: Corr = -0·78, 95 % CI [-1·00, 0·98]; SI: Corr = -0·06, 95 % CI [-0·85, 0·82]) and MDD (SA: Corr = -0·227, 95 % CI [-0·419, -0·017]; SI: Corr = -0·14, 95 % CI [-0·33, 0·06]). Results were mixed for BD, with a significant positive association between SA and global executive functioning (Corr = 0·08, 95 % CI [0·01, 0·15]) and negative association with emotion inhibition. Mixed results were observed for processing speed, attention, and learning and memory, transdiagnostically.

LIMITATIONS

There is heterogeneity across sample compositions and cognitive measures. We did not have detailed information on individuals with respect to demographics and comorbidities.

CONCLUSIONS

We observed a transdiagnostic association between measures of cognitive functions and aspects of suicidality. The interplay of cognitive disturbances, particularly in reward-based functioning, may underlie suicidality in individuals with mental disorders. Disturbances in impulse control, planning, and working memory may contribute to self-injurious behavior and suicide.

Human stem cell-based models to study synaptic dysfunction and cognition in schizophrenia: A narrative review

Cognitive impairment is the strongest predictor of functional outcomes in schizophrenia and is hypothesized to result from synaptic dysfunction. However, targeting synaptic plasticity and cognitive deficits in patients remains a significant clinical challenge. A comprehensive understanding of synaptic plasticity and the molecular basis of learning and memory in a disease context can provide specific targets for the development of novel therapeutics targeting cognitive impairments in schizophrenia. Here, we describe the role of synaptic plasticity in cognition, summarize evidence for synaptic dysfunction in schizophrenia and demonstrate the use of patient derived induced-pluripotent stem cells for studying synaptic plasticity in vitro. Lastly, we discuss current advances and future technologies for bridging basic science research of synaptic dysfunction with clinical and translational research that can be used to predict treatment response and develop novel therapeutics.

Usability and user experience impressions of older adults with cognitive impairment and people with schizophrenia towards GRADIOR, a cognitive rehabilitation program: A cross-sectional study

OBJECTIVE

The aim of this study was to evaluate and compare the impressions of older adults with mild dementia/MCI (mild cognitive impairment) and people with schizophrenia towards the usability of GRADIOR (version 4.5) and their user experience (UX) with this computerized cognitive rehabilitation program.

METHODS

The impressions towards the usability of GRADIOR and the UX of 41 older adults with mild dementia/MCI and 41 people with schizophrenia were obtained using the User Experience Questionnaire.

RESULTS

Older adults with dementia/MCI had more positive impressions than people with schizophrenia. Both agreed that its quality was lower in Dependability.

CONCLUSION

GRADIOR meets users' needs and preferences but needs improvements to ensure they feel more in control when interacting with it. For people with schizophrenia, other aspects of usability and UX need improvement. Usability and UX evaluation allow the verification of technological acceptability and functionality, and to identifying specific improvements for each user group.

Frontal brain volume correlates of impaired executive function in schizophrenia

Cognitive impairments affect functional capacity in individuals with schizophrenia (SZH), but their neural basis remains unclear. The Wisconsin Card Sorting Test (WCST), and the Stroop Task (SCWT), are paradigmatic tests which have been used extensively for examining executive function in SZH. However, few studies have explored how deficits on these tasks link to brain volume differences commonly seen in SZH. Here, for the first time, we tested associations between FreeSurfer-derived frontal brain volumes and performance on both WCST and SCWT, in a well-matched sample of 57 SZH and 32 control subjects. We also explored whether these associations were dissociable from links to symptom severity in SZH. Results revealed correlations between volumes and task performance which were unique to SZH. In SZH only, volumes of right middle frontal regions correlated with both WCST and Stroop performance: correlation coefficients were significantly different to those present in the control group, highlighting their specificity to the patient group. In the Stroop task, superior frontal regions also showed associations with Stroop interference scores which were unique to SZH. These findings provide important detail around how deficits on these two paradigmatic executive function tasks link to brain structural differences in SZH. Results align with converging evidence suggesting that neuropathology within right middle frontal regions (BA9 and BA46) might be of particular import in SZH. No volumetric associations with symptom severity were found, supporting the notion that the structural abnormalities underpinning cognitive deficits in SZH differ from those associated with symptomatology.

Circulating Cell-Free Mitochondrial DNA in Plasma of Individuals with Schizophrenia and Cognitive Deficit in Mexican Population

Purpose

Cognitive domains are affected in patients with schizophrenia. Mitochondrial dysfunction has been proposed as a possible origin of these symptoms. Cell-free mitochondrial DNA (cf-mtDNA) is an indicator of cellular stress, and it can be identified in individuals with age-associated disorders, this study aimed to explore the presence of cf-mtDNA in plasma of schizophrenia patients and its association with cognitive deficit.

Patients and Methods

Ninety-nine subjects were clinically evaluated; the case group included 60 patients diagnosed with schizophrenia and 39 randomly-individuals without psychiatric disorders were included in the comparison group. Cognitive status (MoCA scale) and cell-free mtDNA in blood plasma were assessed and quantified in both groups.

Results

From the original sample, cf-mtDNA was identified in 43 subjects, 40 patients with schizophrenia and 3 controls (Χ2 = 31.10, p-value < 0.0001). Thirty-nine out of forty patients with schizophrenia had a cognitive deficit.

Conclusion

According to our findings, cognitive impairment and presence of cf-mtDNA were related in subjects with schizophrenia. Thus, while the cognitive deficit might reflect an accelerated aging process, the cf-mtDNA plays a role as a potential biomarker in this mechanism.

Cognitive subgroups of affective and non-affective psychosis show differences in medication and cortico-subcortical brain networks

Cognitive deficits are prevalent in individuals with psychosis and are associated with neurobiological changes, potentially serving as an endophenotype for psychosis. Using the HCP-Early-Psychosis-dataset (n = 226), we aimed to investigate cognitive subtypes (deficit/intermediate/spared) through data-driven clustering in affective (AP) and non-affective psychosis patients (NAP) and controls (HC). We explored differences between three clusters in symptoms, cognition, medication, and grey matter volume. Applying principal component analysis, we selected features for clustering. Features that explained most variance were scores for intelligence, verbal recognition and comprehension, auditory attention, working memory, reasoning and executive functioning. Fuzzy K-Means clustering on those features revealed that the subgroups significantly varied in cognitive impairment, clinical symptoms, and, importantly, also in medication and grey matter volume in fronto-parietal and subcortical networks. The spared cluster (86%HC, 37%AP, 17%NAP) exhibited unimpaired cognition, lowest symptoms/medication, and grey matter comparable to controls. The deficit cluster (4%HC, 10%AP, 47%NAP) had impairments across all domains, highest symptoms scores/medication dosage, and pronounced grey matter alterations. The intermediate deficit cluster (11%HC, 54%AP, 36%NAP) showed fewer deficits than the second cluster, but similar symptoms/medication/grey matter to the spared cluster. Controlling for medication, cognitive scores correlated with grey matter changes and negative symptoms across all patients. Our findings generally emphasize the interplay between cognition, brain structure, symptoms, and medication in AP and NAP, and specifically suggest a possible mediating role of cognition, highlighting the potential of screening cognitive changes to aid tailoring treatments and interventions.

Association of P50 with social function, but not with cognition in patients with first-episode schizophrenia

Functional deficits including cognitive impairment and social dysfunction are the core symptoms of schizophrenia (SCZ), and sensory gating (SG) deficits may be involved in the pathological mechanism of functional deficits in SCZ. This study was to investigate the relationship between defective P50 inhibition and functional deficits in first-episode drug naïve (FEDN) SCZ patients. A total of 95 FEDN SCZ patients and 53 healthy controls (HC) were recruited. The Chinese version of UCSD Performance-Based Skills (UPSA), MATRICS Consensus Cognitive Battery (MCCB), and EEG system were used to assess the social function, cognitive performance, and P50 inhibition, respectively. The MCCB total score and eight domain scores were significantly lower in patients with FEDN SCZ than those in HC (all p < 0.05). The UPSA total score and financial skills scores were also significantly lower in SCZ patients than that in the HC (all p < 0.05). Compared with HC, patients with FEDF SCZ had a higher P50 ratio (all p < 0.05). There was no correlation between P50 components and MCCB scores in patients with FEDF SCZ. However, there was only a correlation between the P50 ratio and UPSA financial skills, communication skills, or total score in patients (all p < 0.05). Defective P50 inhibition in FEDN SCZ patients may be associated with social dysfunction but not cognitive impairment, suggesting that the social dysfunction and cognitive impairment of patients with FEDN SCZ may have different pathogenic mechanisms.

Improving outcome of treatment-resistant schizophrenia: effects of cognitive remediation therapy

Treatment-Resistant Schizophrenia (TRS) represents a main clinical issue, associated with worse psychopathological outcomes, a more disrupted neurobiological substrate, and poorer neurocognitive performance across several domains, especially in verbal abilities. If cognitive impairment is a major determinant of patients' functional outcomes and quality of life, targeting cognitive dysfunction becomes even more crucial in TRS patients in order to minimize cognitive and functional deterioration. However, although Cognitive Remediation Therapy (CRT) represents the best available tool to treat cognitive dysfunction in schizophrenia, specific evidence of its efficacy in TRS is lacking. Based on these premises, our study aimed at investigating possible differences in CRT outcomes in a sample of 150 patients with schizophrenia, stratified according to antipsychotic response (TRS vs. non-TRS). Subjects were assessed for neurocognition through Brief Assessment of Cognition in Schizophrenia (BACS) and the Wisconsin Card Sorting Test (WCST) at baseline and after CRT. As expected, we observed greater baseline impairment among TRS patients in BACS-Verbal Memory and WCST-Executive Functions. Repeated measures ANCOVAs showed significant within-group pre-/post-CRT differences in the above-mentioned domains, both among non-TRS and TRS subjects. However, after CRT, no differences were observed between groups. This is the first study to indicate that CRT represents a highly valuable resource for TRS patients, since it may be able to fill the cognitive gap between treatment response groups. Our finding further highlights the importance of early implementation of CRT in addition to pharmacotherapy to reduce the cognitive and functional burden associated with the disease, especially for TRS patients.

Illness-related variables and abnormalities of resting-state brain activity in schizophrenia

Background

The development of neuroimaging biomarkers in patients with schizophrenia (SCZ) requires a refined clinical characterization. A limitation of the neuroimaging literature is the partial uptake of progress in characterizing disease-related features, particularly negative symptoms (NS) and cognitive impairment (CI). In the present study, we assessed NS and CI using up-to-date instruments and investigated the associations of abnormalities in brain resting-state (rs)-activity with disease-related features.

Methods

Sixty-two community-dwelling SCZ subjects participated in the study. Multiple regression analyses were performed with the rs-activity of nine regions of interest as dependent variables and disease-related features as explanatory variables.

Results

Attention/vigilance deficits were negatively associated with dorsal anterior cingulate rs-activity and, together with depression, were positively associated with right dorsolateral prefrontal cortex rs-activity. These deficits and impairment of Reasoning/problem-solving, together with conceptual disorganization, were associated with right inferior parietal lobule and temporal parietal junction rs-activity. Independent of other features, the NS Expressive Deficit domain was associated with the left ventral caudate, while the Motivational Deficit was associated with the dorsal caudate rs-activity.

Conclusion

Neurocognitive deficits and the two negative symptom domains are associated with different neural markers. Replications of these findings could foster the identification of clinically actionable biomarkers of poor functional outcomes.

CSMD1 rs10503253 increases schizophrenia risk in a Tunisian population-group

OBJECTIVES

Schizophrenia is a complex and chronic neuropsychiatric disorder. Recent genome-wide association studies have identified several at risk genetic variants, including two single nucleotide polymorphisms, namely the rs10503253 and the rs1270942 respectively located in the CSMD1 and the CFB loci. The present case-control study was designed to assess potential associations between the two variants and the risk of developing schizophrenia and disease severity. Further we demonstrate the relationship between these variants and clinical characteristics in a population-group from Tunisia.

PATIENTS AND METHODS

In total, 216 patients diagnosed with schizophrenia along with176 healthy controls were included in this case-control study. The molecular analysis of the two polymorphisms was performed using tetra the Primer Amplification Refractory Mutation System-Polymerase Chain method. The statistical analysis was done using Compare V2.1 software, and correlations between genetic results and clinical characteristics were examined by Kruskal-Wallis testing.

RESULTS

The frequency of the rs10503253A allele was found significantly higher among patients with schizophrenia as compared to healthy controls and associated with high negative PANSS scores. While no association was found concerning the implication of the rs1270942 variant in schizophrenia risk, a positive correlation with high positive PANSS scores was further observed.

CONCLUSION

The present finding confirms the previously reported association between the Cub and Sushi multiple Domain 1 rs10503253A allele and the risk to develop schizophrenia and identified the rs1270942 variant as a potential disease risk modifier. Such observations may be important for the definition of the susceptible immunogenetic background in North African individuals at risk to develop mental disorders.

The relationship between peripheral immune cell markers and cognitive functions in patients with schizophrenia

OBJECTIVES

The purpose of this study was to investigate the relationship between peripheral immune cell markers and cognitive functions in patients with schizophrenia and healthy controls.

METHODS

Thirty-five patients diagnosed with schizophrenia with a stable course and a control group of 35 individuals matched in terms of sex, education, and age were included in this cross-sectional study. The Wisconsin Card Sorting Test (WCST), the Rey Auditory Verbal Learning Test (RAVLT), and the Stroop Test were used for neuropsychological evaluation. Blood neutrophil and lymphocyte percentages, neutrophil-lymphocyte ratio (NLR), and systemic immune-inflammation index (SII) values were calculated.

RESULTS

The female patients exhibited significantly higher NLR and neutrophil percentages than the female controls and higher NLR, neutrophil percentage, and SII than the male patients. The increased neutrophil percentages and NLR and decreased lymphocyte percentages in the female patients were significantly correlated with worsening Stroop interference and RAVLT 1 scores. Additionally, a longer duration of illness was significantly correlated with elevated NLR, SII, and neutrophil percentage and a decreased lymphocyte percentage. A higher number of previous hospitalizations was correlated with elevated SII and decreased lymphocyte percentages. Regression analysis showed a significant association between neutrophil percentages and Stroop interference scores used to evaluate attentional functions in patients with schizophrenia.

CONCLUSIONS

These study results suggest that gender and the course of the illness may affect NLR and SII values. An elevated neutrophil percentage may be one of the factors affecting attentional dysfunction in patients with schizophrenia. Prospective studies are now needed to verify these findings.

Increased regional activity of a pro-autophagy pathway in schizophrenia as a contributor to sex differences in the disease pathology

Based on recent genome-wide association studies, it is theorized that altered regulation of autophagy contributes to the pathophysiology of schizophrenia and bipolar disorder. As activity of autophagy-regulatory pathways is controlled by discrete phosphorylation sites on the relevant proteins, phospho-protein profiling is one of the few approaches available for enabling a quantitative assessment of autophagic activity in the brain. Despite this, a comprehensive phospho-protein assessment in the brains of schizophrenia and bipolar disorder subjects is currently lacking. Using this direction, our broad screening identifies an increase in AMP-activated protein kinase (AMPK)-mediated phospho-activation of the pro-autophagy protein beclin-1 solely in the prefrontal cortex of female, but not male, schizophrenia subjects. Using a reverse translational approach, we surprisingly find that this increase in beclin-1 activity facilitates synapse formation and enhances cognition. These findings are interpreted in the context of human studies demonstrating that female schizophrenia subjects have a lower susceptibility to cognitive dysfunction than males.

High-Density Lipoprotein Correlates with Cognitive Functioning in Schizophrenic Women

(1) Background: Schizophrenia is a chronic and progressive neuropsychiatric illness. Apart from positive and negative symptoms, 98% of the population diagnosed with schizophrenia have impaired cognitive functioning, which significantly influences the quality of life. The correlation between lipids and cognitive functioning has been well established. Our study aimed to investigate correlations between cognitive functions, the severity of schizophrenia symptoms, and lipid profiles. (2) Methods: Fifty-two women diagnosed with schizophrenia participated in this study. Cognitive functioning was measured using the Wisconsin Card Sorting Test (WCST). The Positive and Negative Symptom Scale (PANSS) was used. The serum lipid profile, including low-density lipoproteins (LDLs), high-density lipoproteins (HDLs), and triglycerides was measured. (3) Results: Better cognitive functions were associated with normal HDL levels, while low HDL levels correlated with worse WSCT scores. Only the PANSS negative subscale showed a correlation with HDL levels. Correlations with chronicity of schizophrenia and the patient's age with poorer cognitive functions, but not with symptom severity, were detected. Early/late age at onset did not influence WSCT scores. (4) Conclusions: Our results suggest high HDL levels might be a protective factor against cognitive impairment. The influences of age and illness duration also play a vital role in cognitive performance.

Virtual Compensatory Cognitive Training (Virtual-CCT) - A study on acceptability and feasibility

Background

Cognitive impairments in individuals with psychotic disorders impact day-to-day activities and social and occupational functioning (Bowie CR, 2006). Most of the cognitive interventions were developed in the west focusing mainly on clinical research and were not available in routine care. Adaptability and accessibility of these techniques in low-resource settings like India had major challenges. Keeping this in mind, Compensatory Cognitive Training (CCT), being an economical and noncomputerized intervention, was adapted to be used for an urban English-speaking population in India.

Aim

The study aimed to determine the acceptability and feasibility of delivering CCT to persons with schizophrenia through virtual one-on-one sessions.

Materials and Methods

Patients with a diagnosis of schizophrenia were assessed for their subjective and objective cognitive deficits. CCT was delivered for 13 participants as a virtual one - one session. Three participants dropped out midway. Semistructured interview was conducted with all ten participants who completed the intervention to understand their acceptability of Virtual CCT. Feasibility was assessed using a visual analog scale on their attendance, involvement, and comprehending ability. The mean percentile scores on cognitive domains at baseline and end of intervention were analyzed.

Results

Significant change was observed in specific domains of cognition. Participant involvement, lesser dropout rates, and their feedback indicated that Virtual CCT is a feasible and acceptable intervention.

Conclusion

Virtually delivered CCT appears to be an acceptable and feasible intervention to increase access to cognitive interventions for persons with schizophrenia in LAMI countries. This needs to be tested in larger populations.

New clues for the role of cerebellum in schizophrenia and the associated cognitive impairment

Schizophrenia (SZ) is a complex neuropsychiatric disorder associated with severe cognitive dysfunction. Although research has mainly focused on forebrain abnormalities, emerging results support the involvement of the cerebellum in SZ physiopathology, particularly in Cognitive Impairment Associated with SZ (CIAS). Besides its role in motor learning and control, the cerebellum is implicated in cognition and emotion. Recent research suggests that structural and functional changes in the cerebellum are linked to deficits in various cognitive domains including attention, working memory, and decision-making. Moreover, cerebellar dysfunction is related to altered cerebellar circuit activities and connectivity with brain regions associated with cognitive processing. This review delves into the role of the cerebellum in CIAS. We initially consider the major forebrain alterations in CIAS, addressing impairments in neurotransmitter systems, synaptic plasticity, and connectivity. We then focus on recent findings showing that several mechanisms are also altered in the cerebellum and that cerebellar communication with the forebrain is impaired. This evidence implicates the cerebellum as a key component of circuits underpinning CIAS physiopathology. Further studies addressing cerebellar involvement in SZ and CIAS are warranted and might open new perspectives toward understanding the physiopathology and effective treatment of these disorders.

Neuroimaging features of cognitive impairments in schizophrenia and major depressive disorder

Cognitive dysfunctions are one of the key symptoms of schizophrenia (SZ) and major depressive disorder (MDD), which exist not only during the onset of diseases but also before the onset, even after the remission of psychiatric symptoms. With the development of neuroimaging techniques, these non-invasive approaches provide valuable insights into the underlying pathogenesis of psychiatric disorders and information of cognitive remediation interventions. This review synthesizes existing neuroimaging studies to examine domains of cognitive impairment, particularly processing speed, memory, attention, and executive function in SZ and MDD patients. First, white matter (WM) abnormalities are observed in processing speed deficits in both SZ and MDD, with distinct neuroimaging findings highlighting WM connectivity abnormalities in SZ and WM hyperintensity caused by small vessel disease in MDD. Additionally, the abnormal functions of prefrontal cortex and medial temporal lobe are found in both SZ and MDD patients during various memory tasks, while aberrant amygdala activity potentially contributes to a preference to negative memories in MDD. Furthermore, impaired large-scale networks including frontoparietal network, dorsal attention network, and ventral attention network are related to attention deficits, both in SZ and MDD patients. Finally, abnormal activity and volume of the dorsolateral prefrontal cortex (DLPFC) and abnormal functional connections between the DLPFC and the cerebellum are associated with executive dysfunction in both SZ and MDD. Despite these insights, longitudinal neuroimaging studies are lacking, impeding a comprehensive understanding of cognitive changes and the development of early intervention strategies for SZ and MDD. Addressing this gap is critical for advancing our knowledge and improving patient prognosis.

Unravelling the genetic basis of Schizophrenia

Neuronal development is a highly regulated mechanism that is central to organismal function in animals. In humans, disruptions to this process can lead to a range of neurodevelopmental phenotypes, including Schizophrenia (SCZ). SCZ has a significant genetic component, whereby an individual with an SCZ affected family member is eight times more likely to develop the disease than someone with no family history of SCZ. By examining a combination of genomic, transcriptomic and epigenomic datasets, large-scale 'omics' studies aim to delineate the relationship between genetic variation and abnormal cellular activity in the SCZ brain. Herein, we provide a brief overview of some of the key omics methods currently being used in SCZ research, including RNA-seq, the assay for transposase-accessible chromatin with high-throughput sequencing (ATAC-seq) and high-throughput chromosome conformation capture (3C) approaches (e.g., Hi-C), as well as single-cell/nuclei iterations of these methods. We also discuss how these techniques are being employed to further our understanding of the genetic basis of SCZ, and to identify associated molecular pathways, biomarkers, and candidate drug targets.

Uncinate fasciculus microstructural organisation and emotion recognition in schizophrenia: controlling for hit rate bias

Introduction

Schizophrenia (SCZ) is a complex neurodevelopmental disorder characterised by functional and structural brain dysconnectivity and disturbances in perception, cognition, emotion, and social functioning. In the present study, we investigated whether the microstructural organisation of the uncinate fasciculus (UF) was associated with emotion recognition (ER) performance. Additionally, we investigated the usefulness of an unbiased hit rate (UHR) score to control for response biases (i.e., participant guessing) during an emotion recognition task (ERT).

Methods

Fifty-eight individuals diagnosed with SCZ were included. The CANTAB ERT was used to measure social cognition. Specific ROI manual tract segmentation was completed using ExploreDTI and followed the protocol previously outlined by Coad et al. (2020).

Results

We found that the microstructural organisation of the UF was significantly correlated with physical neglect and ER outcomes. Furthermore, we found that the UHR score was more sensitive to ERT subscale emotion items than the standard HR score. Finally, given the association between childhood trauma (in particular childhood neglect) and social cognition in SCZ, a mediation analysis found evidence that microstructural alterations of the UF mediated an association between childhood trauma and social cognitive performance.

Discussion

The mediating role of microstructural alterations in the UF on the association between childhood trauma and social cognitive performance suggests that early life adversity impacts both brain development and social cognitive outcomes for people with SCZ. Limitations of the present study include the restricted ability of the tensor model to correctly assess multi-directionality at regions where fibre populations intersect.

Evidence for shallow cognitive maps in schizophrenia

Individuals with schizophrenia can have marked deficits in goal-directed decision making. Prominent theories differ in whether schizophrenia (SZ) affects the ability to exert cognitive control, or the motivation to exert control. An alternative explanation is that schizophrenia negatively impacts the formation of cognitive maps, the internal representations of the way the world is structured, necessary for the formation of effective action plans. That is, deficits in decision-making could also arise when goal-directed control and motivation are intact, but used to plan over ill-formed maps. Here, we test the hypothesis that individuals with SZ are impaired in the construction of cognitive maps. We combine a behavioral representational similarity analysis technique with a sequential decision-making task. This enables us to examine how relationships between choice options change when individuals with SZ and healthy age-matched controls build a cognitive map of the task structure. Our results indicate that SZ affects how people represent the structure of the task, focusing more on simpler visual features and less on abstract, higher-order, planning-relevant features. At the same time, we find that SZ were able to display similar performance on this task compared to controls, emphasizing the need for a distinction between cognitive map formation and changes in goal-directed control in understanding cognitive deficits in schizophrenia.

Aripiprazole Attenuates Cognitive Impairments Induced by Lipopolysaccharide in Rats through the Regulation of Neuronal Inflammation, Oxidative Stress, and Apoptosis

Background and Objectives: Aripiprazole (APZ), an atypical antipsychotic, is mainly prescribed for conditions such as schizophrenia and bipolar disorder, while ongoing research indicates promising neuroprotective qualities. APZ's mechanism of action, involving the regulation of neurotransmitter levels, appears to contribute to its potential to shield neural tissues from specific forms of harm and degeneration. Materials and Methods: To investigate its neuroprotective mechanisms, groups of rats were orally administered APZ at 1 or 2 mg/kg once daily for a 30-day period. In addition, neuronal toxicity was induced through intraperitoneal injection of four doses of lipopolysaccharide (LPS) at a concentration of 1 mg/kg. To evaluate cognitive function, particularly, short-term recognition memory, the procedure implemented the novel object recognition (NOR) task. Subsequently, brain tissues were gathered to examine markers linked with neuroinflammation, oxidative stress, and apoptosis. Results: The administration of LPS led to a decline in memory performance during the NOR tasks. Simultaneously, this LPS treatment raised inflammatory markers like cyclooxygenase (COX)-2, tumor necrosis factor (TNF)-α, and nuclear factor kappa B (NF-κB), increased oxidative markers such as malondialdehyde (MDA), and triggered apoptosis markers like Caspase-3 and Bcl2 associated X protein (Bax) within the brain. Furthermore, it decreased levels of antioxidants like reduced glutathione (GSH) and catalase, as well as the anti-apoptotic marker B-cell lymphoma (Bcl)-2 in brain tissue. The use of APZ resulted in enhanced recognition memory performance, as indicated by improved exploration and discrimination abilities of the objects in the NOR task. Moreover, APZ lowered the markers associated with neuronal vulnerability, such as COX-2, NF-κB, MDA, Caspase-3, and Bax. Additionally, it increased the levels of protective markers, including GSH, catalase, and Bcl-2 in LPS-challenged brains. Conclusions: In summary, the findings suggest that APZ exhibits protective properties against neuronal inflammation, oxidative stress, and apoptosis markers in the context of inflammatory-related neurodegeneration. Additional in-depth investigations are needed to further explore potential applications.

Evaluation of the Relationships between Irisin Levels and Cognitive Functions in Individuals with Schizophrenia

Objective

: Irisin is a myokine that is involved in neurogenesis, neuronal proliferation, and neuronal differentiation. Many research examine the relationship between irisin and schizophrenia. In this study, we aimed to evaluate the relationship between irisin levels and cognitive functions in individuals with schizophrenia.

Methods

: Ninety-six individuals who were diagnosed with schizophrenia were included. The Brief Psychiatric Rating Scale (BPRS) was used to assess disease severity. To evaluate the cognitive functions of the patients, the trail-making test was evaluated with the A and B forms and the verbal memory processes scale. After a 12-hour night fast, samples of fasting blood were obtained from the participants.

Results

: There was no significant correlation between irisin, duration of disease, and BPRS total score. In the analysis performed, a positive correlation was found between the plasma irisin level and the error score of the trail-making test form B. Other than that, no correlation was found between irisin level and cognitive performance in schizophrenia patients. In addition, in subgroup analysis between genders, it was determined that the duration of the trail-making test B was longer in female schizophrenia patients.

Conclusion

: In this study, there was a positive correlation between the trail-making test B-form error scores and the irisin levels. This relationship between impaired executive functions and irisin levels may suggest that the irisin level is increased as compensation for the impairment in executive functions. More research is needed to understand the role of irisin in cognitive impairment and schizophrenia.

A randomized controlled trial of Vitamin D supplementation in Iranian patients with schizophrenia: Effects on serum levels of glycogen synthase kinase-3β and symptom severity

BACKGROUND

Growing evidence has shown that hypovitaminosis D is a risk factor for developing schizophrenia and comorbid conditions. Therefore, this study aimed to examine the effect of vitamin D supplementation on serum levels of vitamin D, metabolic factors related to insulin resistance (IR) and the severity of the disorder in patients with schizophrenia.

METHODS

Forty-eight chronic male patients with schizophrenia with vitamin D deficiency (≤20 ng/mL= (≤50 nmol/l) were selected and randomly assigned to vitamin D treatment and placebo groups. Subjects were supplemented for 8 weeks with vitamin D (2000 IU/day) or placebo.

RESULTS

Within-group comparison revealed that the vitamin D group had a significant reduction in waist circumference, Positive and Negative Syndrome Scale - total score (PANSS-TS), and glycogen synthase kinase 3 beta (GSK-3β) levels (P = .022, P = <.001 and P = .013, respectively). On the other hand, the placebo group showed a significant increase in the level of fasting serum insulin and Homeostatic Model Assessment of Insulin Resistance (HOMA-IR) (P = .003 and P = .003). The between-group comparison showed a significant difference in terms of PANSS-TS, GSK-3β, fasting serum insulin (FSI), and HOMA-IR (P = .022, P = .048, P = .013 and P = .014 respectively).

CONCLUSIONS

Among vitamin D deficient patients with schizophrenia, vitamin D supplementation may affect GSK-3 β, an important biomarker in schizophrenia and insulin resistance. In addition, vitamin D supplementation in such patients may reduce the disorder's symptom severity.

Immediate post performance judgements about cognitive performance in schizophrenia and bipolar disorder: associations with test performance and subjective overall judgments regarding abilities

INTRODUCTION

The study explored associations between the accuracy of post assessment judgements of cognitive performance with global self-assessments of psychosocial functioning compared to evaluations generated by observers in schizophrenia and bipolar disorder.

METHODS

An abbreviated cognitive assessment based on the MATRICS Consensus Cognitive Battery was administered to 122 individuals with schizophrenia and 113 with bipolar disorder. They provided self-estimates of their performance after each subtest. In addition, self-reports on cognition, social cognition, and everyday functioning were collected and compared to observer ratings.

RESULTS

Both groups overestimated their cognitive function, but in bipolar disorder, there was 30% shared variance between task performance and self-rated task performance (vs. 5% in schizophrenia). Significant correlations were found between self-reported everyday outcomes and both actual and self-assessed performance. In schizophrenia, immediate judgements were only related to self-rated functioning, not to observer rated functioning. In bipolar disorder, impairments in self-assessment of performance correlated with observer ratings of cognitive ability, which was not observed in schizophrenia.

CONCLUSIONS

While both groups showed correlations between cognitive performance and introspective accuracy, individuals with bipolar disorder showed higher accuracy in assessing their cognitive performance and other outcomes. Notably, impairments in introspective accuracy were associated with observer-rated functioning exclusively in bipolar disorder.

The social cognitive and neural mechanisms that underlie social functioning in individuals with schizophrenia - a review

In many individuals with a diagnosis of schizophrenia social functioning is impaired across the lifespan. Social cognition has emerged as one of the possible factors that may contribute to these challenges. Neuroimaging research can give further insights into the underlying mechanisms of social (cognitive) difficulties. This review summarises the evidence on the associations between social cognition in the domains of theory of mind and emotion perception and processing, and individuals' social functioning and social skills, as well as associated neural mechanisms. Eighteen behavioural studies were conducted since the last major review and meta-analysis in the field (inclusion between 7/2017 and 1/2022). No major review has investigated the link between the neural mechanisms of social cognition and their association with social functioning in schizophrenia. Fourteen relevant studies were included (from 1/2000 to 1/2022). The findings of the behavioural studies showed that associations with social outcomes were slightly stronger for theory of mind than for emotion perception and processing. Moreover, performance in both social cognitive domains was more strongly associated with performance on social skill measures than questionnaire-based assessment of social functioning in the community. Studies on the underlying neural substrate of these associations presented mixed findings. In general, higher activation in various regions of the social brain was associated with better social functioning. The available evidence suggests some shared regions that might underlie the social cognition-social outcome link between different domains. However, due to the heterogeneity in approaches and findings, the current knowledge base will need to be expanded before firm conclusions can be drawn.

Exploring the Effectiveness of Group Cognitive Stimulation Training in People With Schizophrenia: A Randomized Controlled Trial

BACKGROUND

Schizophrenia is a chronic degenerative brain disease. Cognitive impairment, the core symptom of this disease, affects the mood and social functioning of patients severely. Nonpharmacological therapies that both improve cognitive function and are suitable for patients with schizophrenia remain underdeveloped.

PURPOSE

This article was designed to explore the effects of group cognitive stimulation training (GCST) on cognitive function and social function in people with schizophrenia.

METHODS

A randomized controlled trial was conducted. The 76 participants were allocated into either the experimental or control group using blocked randomization. The participants were all patients with chronic schizophrenia recruited from seven rehabilitation units in northern Taiwan who were 20-65 years old and scored 10-25 on the Montreal Cognitive Assessment Taiwan Version. The experimental group received the 60-minute GCST twice a week for 7 weeks, whereas the control group received standard treatment. All outcome indicators were analyzed at baseline and after intervention using generalized estimating equations. The primary outcome indicators included cognitive function assessed using the Taiwan version of the Montreal Cognitive Assessment, working memory assessed using the Wechsler Memory Scale-Third Edition, and executive function assessed using the Taiwanese version of the Frontal Assessment Battery. The secondary outcome indicator was social function assessed using the Social Function Scale-Taiwan short version.

RESULTS

Generalized estimating equation modeling revealed the experimental group exhibited significant improvement in Montreal Cognitive Assessment total score ( B = 1.33, SE = 0.65, p = .040) and Social Function Scale-Taiwan short version ( B = 9.55, SE = 2.38, p < .001) after adjusting for nine covariates. No significant differences between the two groups in terms of working memory ( B = 4.79, SE = 2.66, p = .071) or executive function ( B = 0.53, SE = 0.63, p = .399) were found.

CONCLUSIONS/IMPLICATIONS FOR PRACTICE

The results indicate that GCST positively impacts overall cognitive and social functions but not higher-order cognitive function (working memory and executive function). In clinical settings, GCST may be applied to improve cognitive function in people with schizophrenia. The findings of this study may inform the practice of mental health nurses to improve cognitive function in patients in clinical care.

Altered levels of fecal short-chain fatty acids are associated with subclinical inflammation and worse cognitive performance in patients with schizophrenia

Schizophrenia is a multi-systemic disorder that is associated with lipid profile disturbances, altered glucose homeostasis and subclinical inflammation. It has been proposed that dysfunction of the gut-brain axis might underlie these alterations. Short-chain fatty acids (SCFAs) are considered to play a pivotal role in the gut-brain axis. In this study, we aimed to compare fecal levels of SCFAs in patients with schizophrenia and healthy controls (HCs), taking into consideration their relationship with common peripheral blood alterations observed in schizophrenia. The study included 100 stable outpatients with schizophrenia and 55 HCs. The levels of SCFAs (acetic acid, propionic acid, butyric acid, isobutyric acid, valeric acid, isovaleric acid, and lactic acid) in fecal samples were measured. Also, lipid profile together with the levels of C-reactive protein, glucose and insulin were determined. The levels of isovaleric acid were significantly higher in patients with schizophrenia after co-varying for age, sex, and the adherence to the Mediterranean diet. Moreover, there were significant positive correlations of the levels of valeric acid, isovaleric acid and CRP in patients with schizophrenia. In this group of participants, higher levels of isovaleric acid were associated with significantly lower scores of delayed memory after adjustment for potential covariates and interactions with CRP levels. Our results indicate that individuals with schizophrenia show altered levels of isovaleric acid that might be associated with impairments of delayed memory. The association with cognitive impairments might be independent of interactions with immune-inflammatory processes. Longitudinal and experimental studies are needed to test causal mechanisms of observed correlations.

Modeling psychotic disorders: Environment x environment interaction

Schizophrenia is a major psychotic disorder with multifactorial etiology that includes interactions between genetic vulnerability and environmental risk factors. In addition, interplay of multiple environmental adversities affects neurodevelopment and may increase the individual risk of developing schizophrenia. Consistent with the two-hit hypothesis of schizophrenia, we review rodent models that combine maternal immune activation as the first hit with other adverse environmental exposures as the second hit. We discuss the strengths and pitfalls of the current animal models of environment x environment interplay and propose some future directions to advance the field.

The application of cognitive behavioral therapy in patients with schizophrenia: A review

The aim of this review is to explore the clinical nursing application of cognitive behavioral therapy (CBT) in patients with schizophrenia. A literature search was conducted using the CINAHL and MEDLINE databases. The database search occurred during the month of December 2022. This article comprehensively summarizes the theoretical basis of CBT in improving schizophrenia in clinical nursing, its application in managing symptoms and improving social function, as well as research progress in this field. There are still inconsistencies in the research results on CBT, but overall, psychological intervention combined with drug treatment is more effective than conventional treatment alone. If social function training can be added at the same time, it is believed that it will have better effects on clinical treatment and can maintain long-lasting effectiveness. Only in this way can patients truly understand and recognize the disease, improve treatment compliance, and ultimately achieve the goal of improving prognosis and quality of life.

A Proxy Approach to Family Involvement and Neurocognitive Function in First Episode of Non-Affective Psychosis: Sex-Related Differences

Schizophrenia spectrum disorders (SSD) often show cognitive deficits (CD) impacting daily life. Family support has been shown to be protective against CD, yet the relationship between these in psychotic patients remains complex and not fully understood. This study investigated the association between a subdomain of family support, namely, family involvement (estimated through a proxy measure), cognitive functioning, and sex in first-episode psychosis (FEP) patients. The sample included 308 patients enrolled in the Program for Early Phases of Psychosis (PAFIP), divided into 4 groups based on their estimated family involvement (eFI) level and sex, and compared on various variables. Women presented lower rates of eFI than men (37.1% and 48.8%). Higher eFI was associated with better cognitive functioning, particularly in verbal memory. This association was stronger in women. The findings suggest that eFI may be an important factor in FEP patients' cognitive functioning. This highlights the importance of including families in treatment plans for psychotic patients to prevent CD. Further research is needed to better understand the complex interplay between family support, sex, and cognitive functioning in psychotic patients and develop effective interventions that target these factors.

Patterns of Impaired Neurocognitive Performance on the Global Neuropsychological Assessment, and Their Brain Structural Correlates in Recent-onset and Chronic Schizophrenia

Objective

Schizophrenia is associated with impairment in multiple cognitive domains. There is a paucity of research on the effect of prolonged illness duration (≥ 15 years) on cognitive performance along multiple domains. In this pilot study, we used the Global Neuropsychological Assessment (GNA), a brief cognitive battery, to explore the patterns of cognitive impairment in recent-onset (≤ 2 years) compared to chronic schizophrenia (≥ 15 years), and correlate cognitive performance with brain morphometry in patients and healthy adults.

Methods

We assessed cognitive performance in patients with recent-onset (n = 17, illness duration ≤ 2 years) and chronic schizophrenia (n = 14, duration ≥ 15 years), and healthy adults (n = 16) using the GNA and examined correlations between cognitive scores and gray matter volumes computed from T1-weighted magnetic resonance imaging images.

Results

We observed cognitive deficits affecting multiple domains in the schizophrenia samples. Selectively greater impairment of perceptual comparison speed was found in adults with chronic schizophrenia (p = 0.009, η2partial = 0.25). In the full sample (n = 47), perceptual comparison speed correlated significantly with gray matter volumes in the anterior and medial temporal lobes (TFCE, FWE p < 0.01).

Conclusion

Along with generalized deficit across multiple cognitive domains, selectively greater impairment of perceptual comparison speed appears to characterize chronic schizophrenia. This pattern might indicate an accelerated or premature cognitive aging. Anterior-medial temporal gray matter volumes especially of the left hemisphere might underlie the impairment noted in this domain in schizophrenia.

Dysconnection and cognition in schizophrenia: A spectral dynamic causal modeling study

Schizophrenia (SZ) is a severe mental disorder characterized by failure of functional integration (aka dysconnection) across the brain. Recent functional connectivity (FC) studies have adopted functional parcellations to define subnetworks of large-scale networks, and to characterize the (dys)connection between them, in normal and clinical populations. While FC examines statistical dependencies between observations, model-based effective connectivity (EC) can disclose the causal influences that underwrite the observed dependencies. In this study, we investigated resting state EC within seven large-scale networks, in 66 SZ and 74 healthy subjects from a public dataset. The results showed that a remarkable 33% of the effective connections (among subnetworks) of the cognitive control network had been pathologically modulated in SZ. Further dysconnection was identified within the visual, default mode and sensorimotor networks of SZ subjects, with 24%, 20%, and 11% aberrant couplings. Overall, the proportion of discriminative connections was remarkably larger in EC (24%) than FC (1%) analysis. Subsequently, to study the neural correlates of impaired cognition in SZ, we conducted a canonical correlation analysis between the EC parameters and the cognitive scores of the patients. As such, the self-inhibitions of supplementary motor area and paracentral lobule (in the sensorimotor network) and the excitatory connection from parahippocampal gyrus to inferior temporal gyrus (in the cognitive control network) were significantly correlated with the social cognition, reasoning/problem solving and working memory capabilities of the patients. Future research can investigate the potential of whole-brain EC as a biomarker for diagnosis of brain disorders and for neuroimaging-based cognitive assessment.

Cognitive impairment in schizophrenia: aetiology, pathophysiology, and treatment

Cognitive deficits are a core feature of schizophrenia, account for much of the impaired functioning associated with the disorder and are not responsive to existing treatments. In this review, we first describe the clinical presentation and natural history of these deficits. We then consider aetiological factors, highlighting how a range of similar genetic and environmental factors are associated with both cognitive function and schizophrenia. We then review the pathophysiological mechanisms thought to underlie cognitive symptoms, including the role of dopamine, cholinergic signalling and the balance between GABAergic interneurons and glutamatergic pyramidal cells. Finally, we review the clinical management of cognitive impairments and candidate novel treatments.

Oscillatory Deficits in the Sub-Chronic PCP Rat Model for Schizophrenia Are Reversed by mGlu5 Receptor-Positive Allosteric Modulators VU0409551 and VU0360172

The cognitive deficits of schizophrenia are linked to imbalanced excitatory and inhibitory signalling in the prefrontal cortex (PFC), disrupting gamma oscillations. We previously demonstrated that two mGlu5 receptor-positive allosteric modulators (PAMs), VU0409551 and VU0360172, restore cognitive deficits in the sub-chronic PCP (scPCP) rodent model for schizophrenia via distinct changes in PFC intracellular signalling molecules. Here, we have assessed ex vivo gamma oscillatory activity in PFC slices from scPCP rats and investigated the effects of VU0409551 and VU0360172 upon oscillatory power. mGlu5 receptor, protein kinase C (PKC), and phospholipase C (PLC) inhibition were also used to examine ‘modulation bias’ in PAM activity. The amplitude and area power of gamma oscillations were significantly diminished in the scPCP model. Slice incubation with either VU0409551 or VU0360172 rescued scPCP-induced oscillatory deficits in a concentration-dependent manner. MTEP blocked the PAM-induced restoration of oscillatory power, confirming the requirement of mGlu5 receptor modulation. Whilst PLC inhibition prevented the power increase mediated by both PAMs, PKC inhibition diminished the effects of VU0360172 but not VU0409551. This aligns with previous reports that VU0409551 exhibits preferential activation of the phosphatidylinositol-3-kinase (PI3K) signalling pathway over the PKC cascade. Restoration of the excitatory/inhibitory signalling balance and gamma oscillations may therefore underlie the mGluR5 PAM-mediated correction of scPCP-induced cognitive deficits.

The relationship between inflammatory biomarkers and cognitive dysfunction in patients with schizophrenia: A systematic review and meta-analysis

BACKGROUND

Schizophrenia is a complex psychiatric disorder that includes positive and negative symptoms but also debilitating cognitive deficits. Current pharmacological interventions do not target these deficits. Recent evidence suggests a connection between some inflammatory markers (including C-reactive protein) and cognitive impairment, but did not address other inflammatory markers. In the current study, we try to fill the gap by focusing on the association of Interleukin-6 (IL-6), IL-1β, Tumor Necrosis Factor-α and CRP with cognitive dysfunction.

METHODS

PUBMED and Web of Science databases were searched for all studies published until July 2022. A total of 25 studies were included in an analysis of the association between cognitive performance and variation in IL-6, IL-1β, TNF-α and CRP.

RESULTS

A total of 2398 patients were included in this study. Meta-analyses results showed a significant inverse relationship between performance in five cognitive domains (attention-processing speed, executive function, working memory, verbal and visual learning and memory) and systemic IL-6, IL-1β, TNF-α and CRP plasma levels in patients with schizophrenia. The meta-analyses results showed a significant decline in the cognitive performances with the evaluated inflammatory markers with effect sizes ranging from -0.136 to -0.181 for IL-6, -0.188 to -0.38 for TNF-α -0.372 to -0.476 for IL-1β and - 0.168 to -0.311 for CRP.

CONCLUSION

Findings from the current study shows that cognitive deficits are reflective of elevated proinflammatory biomarkers (IL-6, IL-1β, TNF-α and CRP) levels. The results obtained indicate relatedness between inflammation and cognitive decline in patients with schizophrenia. Understanding the underlying pathways between them could have a significant impact on the disease progression and quality of life in schizophrenia patients.

Inflammation and cognition in severe mental illness: patterns of covariation and subgroups

A potential relationship between dysregulation of immune/inflammatory pathways and cognitive impairment has been suggested in severe mental illnesses (SMI), such as schizophrenia (SZ) and bipolar (BD) spectrum disorders. However, multivariate relationships between peripheral inflammatory/immune-related markers and cognitive domains are unclear, and many studies do not account for inter-individual variance in both cognitive functioning and inflammatory/immune status. This study aimed to investigate covariance patterns between inflammatory/immune-related markers and cognitive domains and further elucidate heterogeneity in a large SMI and healthy control (HC) cohort (SZ = 343, BD = 289, HC = 770). We applied canonical correlation analysis (CCA) to identify modes of maximum covariation between a comprehensive selection of cognitive domains and inflammatory/immune markers. We found that poor verbal learning and psychomotor processing speed was associated with higher levels of interleukin-18 system cytokines and beta defensin 2, reflecting enhanced activation of innate immunity, a pattern augmented in SMI compared to HC. Applying hierarchical clustering on covariance patterns identified by the CCA revealed a high cognition-low immune dysregulation subgroup with predominantly HC (24% SZ, 45% BD, 74% HC) and a low cognition-high immune dysregulation subgroup predominantly consisting of SMI patients (76% SZ, 55% BD, 26% HC). These subgroups differed in IQ, years of education, age, CRP, BMI (all groups), level of functioning, symptoms and defined daily dose (DDD) of antipsychotics (SMI cohort). Our findings suggest a link between cognitive impairment and innate immune dysregulation in a subset of individuals with severe mental illness.