Differences in cognitive impairment between schizophrenia and bipolar disorder: Considering the role of heterogeneity

A meta-analysis of data-driven cognitive subgroups in bipolar disorder

The delineation of cognitive subgroups of bipolar disorder (BD) might be helpful for identifying biologically valid subtypes of this disorder. This meta-analysis identified peer-reviewed literature on studies investigating cognitive subgroups of BD with data-driven clustering methods. Relevant studies were searched in PubMed, Scopus, and Web of Science. Random-effects meta-analysis was performed using R software. A total of 14 cross-sectional studies including euthymic or mildly symptomatic patients with BD were included in the current meta-analysis. The available studies have consistently supported a 3-cluster solution. The pooled prevalence of the severe-impairment, moderate-impairment, and major good-functioning groups were 23.1 % (95%CI, 18.5 %-27.7 %), 42.5 % (95%CI, 36.3 %-48.8 %), and 33.5 % (95%CI, 25.9 %-41.1 %) respectively. Compared to healthy controls, both the severe-impairment (g=-1.40 to -1.73) and moderate-impairment groups (g=-0.59 to -0.96) had significant deficits in all six cognitive domains (verbal memory, visual memory, executive functions, working memory, attention and processing speed). The good-performance subgroup had a small increase in the performance of executive functions (g=0.23) and normal functioning in all other domains. Compared to the good-performance subgroup, the severe-impairment subgroup was characterized by more severe functional impairment, more hospital admissions, a higher percentage of type I BD and antipsychotic use. The characteristics of the moderate-impairment subgroup were lying between the other two subgroups for most of the measures. The current findings support the existence of 3 cognitive subgroups in BD including severe-impairment and moderate-impairment groups which are associated with a more severe course of illness.

Are Advanced Oxidation Protein Products (AOPPs) Levels Altered in Neuropsychiatric Disorders? An Integrative Review

Neuropsychiatric disorders such as major depressive disorder (MDD), bipolar disorder (BD), and schizophrenia (SZ) are considered a public health problem since it interferes in personal relationships and at work. The pathophysiological mechanisms of these mental disorders are still not completely understood. The variety and heterogeneity of symptoms, as well as the absence of biomarkers, make the diagnosis, prognosis, and treatment of these disorders difficult. However, oxidative stress appears to play a role in the pathophysiology of these diseases. In this context, advanced oxidation protein products (AOPPs) are considered a biomarker of protein oxidative damage and have been associated with neuroinflammatory diseases. In patients with neuropsychiatric disorders, increased levels of AOPPs were associated with the severity of symptoms and decreased quality of life. Thus, the objective of this integrative review is to investigate and discuss the relationship between AOPPs levels and MDD, BD, and SZ. Different databases were consulted and approximately 112 scientific articles were found relating AOPPs and psychiatric disorders. In the majority of studies, the blood levels of AOPPs were increased in MDD, BD, and SZ and associated with the severity of the disorders. Although the association of this marker with the risk of developing one of these mental disorders is more uncertain, some studies have suggested this relationship. Of the twenty-four studies highlighted, only four did not find significant differences in AOPPs levels in patients with the disorders mentioned. In summary, it may be suggested that the assessment of AOPPs levels can be a useful tool in the evaluation of neuropsychiatric disorders, at least for prognostic evaluation. However, the role of this biomarker in the pathophysiology of mental disorders is still unclear, as well as whether reducing its levels represents a potential therapeutic strategy.

Cognitive reserve and cognition in mood disorders: A systematic review and meta-analysis

Cognitive functioning heterogeneity is a well-recognized phenomenon in individuals diagnosed with mood disorders. Cognitive Reserve (CR) has been linked to multiple positive outcomes, including cognitive performance in these patients. This systematic review and meta-analysis aim to provide a comprehensive analysis of the relationship between CR and cognitive functioning in individuals with mood disorders, including bipolar disorder and depressive disorders. Following PRISMA guidelines, a systematic review and meta-analysis was conducted of original research exploring the relationship between CR and cognitive performance in adult individuals with mood disorders. The literature search was conducted on PubMed, Scopus, and Web of Science, from 2002 to September 2023, and the Newcastle-Ottawa Scale (NOS) was used to evaluate the quality of studies. Overall, 17 studies met the inclusion criteria for the systematic review and 11 for the meta-analysis. Both qualitative and quantitative findings suggested a positive relationship between CR measures and cognitive domains. CR emerges as a possible protective factor for cognitive functioning in adult individuals with mood disorders, potentially helping to mitigate the cognitive impairments associated with the disorder. These findings underscore the importance of the fact that promoting and enhancing CR could help in the cognitive prognosis of this population.

Assessment of Cognitive Performance in Bipolar Disorder Type I Patients and Their Unaffected Offspring

Patients with bipolar disorder type I (BP-I) often present with impairments in cognitive function. Offspring unaffected by the disorder can also present with cognitive dysfunction. The objective of this study was to compare the cognitive function of BP-I patients, their unaffected offspring (UO) and healthy control subjects (HC).

METHODS

Verbal memory, working memory index, processing speed, attention, verbal and phonological fluency and executive function were evaluated through the application of a neuropsychological battery to three groups made up of BP-I patients that attended the Bipolar Disorder Outpatient Clinic of Clínica San Juan de Dios de Manizales [San Juan de Dios de Manizales Clinic] (n=30), UO (n=32) and control group (n=31). The UO group and the control group were matched by gender, age and level of education.

RESULTS

Major differences between the three groups were found in the measures of cognitive functions (except in semantic fluency). The HC group showed better cognitive performance in all the functions. Post-hoc analysis showed similar results in the cognitive performance between BP-I and UO except in verbal learning and executive function tasks where the results were better in UO. A better performance in the control group was found, compared to the UO group, in executive function, attention, working memory, and semantic fluency and phonological areas.

CONCLUSIONS

These results indicate that the offspring of patients with BP-I present with cognitive impairments without suffering from the disorder. This suggests that cognitive dysfunction presents without diagnosis and supports the hypothesis that it can correspond to a BP-I endophenotype.

Hydroxytyrosol Alleviates Obesity-Induced Cognitive Decline by Modulating the Expression Levels of Brain-Derived Neurotrophic Factors and Inflammatory Factors in Mice

Hydroxytyrosol (HT; 3,4-dihydroxyphenyl ethanol) is an important functional polyphenol in olive oil. Our study sought to evaluate the protective effects and underlying mechanisms of HT on obesity-induced cognitive impairment. A high-fat and high-fructose-diet-induced obese mice model was treated with HT for 14 weeks. The results show that HT improved the learning and memory abilities and enhanced the expressions of brain-derived neurotrophic factors (BDNFs) and postsynaptic density proteins, protecting neuronal and synaptic functions in obese mice. Transcriptomic results further confirmed that HT improved cognitive impairment by regulating gene expression in neural system development and synaptic function-related pathways. Moreover, HT treatment alleviated neuroinflammation in the brain of obese mice. To sum up, our results indicated that HT can alleviate obesity-induced cognitive dysfunction by enhancing BDNF expression and alleviating neuroinflammation in the brain, which also means that HT may become a potentially useful nutritional supplement to alleviate obesity-induced cognitive decline.

Can neurological soft signs and neurocognitive deficits serve as a combined endophenotype for Han Chinese with bipolar disorder?

BACKGROUND

Bipolar disorder's (BD) potential endophenotypes include neurological soft signs (NSS) and neurocognitive disorders (ND). Few research, meanwhile, has coupled NSS and ND as combined endophenotypes of BD.

OBJECT

This study intends to investigate NSS and ND and compare their differences in euthymic patients with bipolar disorder (EBP), their unaffected first-degree relatives (FDR), and healthy controls (HC). Additionally, search for potential endophenotypic subprojects of NSS and ND and construct and verify a composite endophenotypic.

METHODS

The subjects were all Han Chinese and consisted of 86 EBP, 81 FDR, and 81HC. Cambridge Neurological Inventory and MATRICSTM Consensus Cognitive Battery tested NSS and ND independently.

RESULTS

All three groups displayed a trapezoidal distribution of NSS levels and cognitive abnormalities, with EBP having the most severe NSS levels and cognitive deficits, followed by FDR and HC. Among them, motor coordination in NSS and Information processing speed (IPS), Verbal learning (VL), and Working memory (WM) in neurocognitive function are consistent with the traits of the endophenotype of BD. The accuracy in differentiating EBP and HC or FDRs and HC was higher when these items were combined as predictor factors than in differentiating EBP and FDR.

CONCLUSION

These results provide more evidence that motor coordination, IPS, VL, and WM may be internal characteristics of bipolar disease. When these characteristics are combined into a complex endophenotype, it may be possible to distinguish BD patients and high-risk groups from normal populations.

Suicidal Ideation and Non-Suicidal Self-Injury Following Early Childhood Psychotic Experiences in Preadolescent Children at Familial High Risk of Schizophrenia or Bipolar Disorder-The Danish High Risk and Resilience Study, VIA 11

BACKGROUND AND HYPOTHESIS

Suicide is a leading cause of death in youth and is often preceded by suicidal ideation (SI) and non-suicidal self-injury (NSSI). Identifying early markers of risk for SI and NSSI could improve timely identification of at-risk individuals.

STUDY DESIGN

Children (mean age 11.9, SD 0.2) at familial high risk of schizophrenia (N = 171), or bipolar disorder (N = 104), and controls (N = 174) were assessed for psychotic experiences (PE), SI, NSSI, and Axis I mental disorders in face-to-face interviews in early and middle childhood (age 7 and 11).

STUDY RESULTS

Having 2 types of early childhood PE predicted middle childhood SI after accounting for previous SI, NSSI, and mental disorders (OR 2.8, 95% CI 1.1-6.9; P = .03). Two PE predicted NSSI (OR 3.0, 95% CI 1.2-7.7; P = .02) in excess of previous SI, NSSI, mental disorders, and familial risk. Persistent and incident PE predicted SI (OR 3.2, 95% CI, 1.1-8.8; P = .03; OR 3.8, 95% CI, 1.3-11.5; P = .02) in the fully adjusted model. Nineteen percent of children with persistent PE reported middle childhood SI vs 3.8% of those who never reported PE. In children with early childhood mental disorders, those who reported 2 PE had 4.4-fold increased odds of later SI (95% CI, 1.2-16.7; P = .03) after adjustments. PE were nondifferentially associated with outcomes across familial risk groups.

CONCLUSIONS

Early childhood PE index elevated risk for subsequent SI and NSSI beyond what can be attributed to presence of mental disorders. Mental health screenings and clinical assessments should include early childhood PE.

Prevalence, correlates and explanatory models of cognitive deficits in patients with schizophrenia-A cross sectional study

Background

Schizophrenia may cause significant impairment in social and economic aspects of a patient's life. Current evidence suggests that cognitive deficits may affect the functioning of a person with schizophrenia more than positive or negative symptoms. There is a lack of literature on explanatory models of cognitive deficits in schizophrenia that can influence help-seeking behavior.

Objectives

This study aimed to estimate the prevalence of cognitive deficits and assess their relationship with socio-demographic and clinical characteristics among patients with schizophrenia. We also planned to explore the explanatory models of cognitive deficits in these patients.

Methods

Consecutive outpatients with schizophrenia who met eligibility criteria were recruited after obtaining informed consent. The Addenbrooke's Cognitive Examination Tamil version (ACE III) and Observable Social Cognition - A Rating Scale (OSCARS) and Positive and Negative Symptom Scale (PANSS) were used to assess cognitive functioning and symptom profile, respectively. Beliefs about illness were recorded using the modified Short Explanatory Model Interview (SEMI). Socio-demographic and treatment-related details were collected with a structured proforma. Statistical analysis was done using SPSS for Windows (version 16.0.1).

Results

One hundred and forty patients participated in the study. The prevalence of cognitive deficits was 75.7% using ACE-III scores, 19.3% on OSCARS, and 40% based on subjective reports. Though the majority (81.4%) of patients reported a medical explanatory model for cognitive impairment, a significant number of them (70.7%) also held non-medical models simultaneously.

Conclusion

Cognitive deficits are prevalent in the majority of patients with schizophrenia. Poor test performance on cognitive testing was observed in those with a significant family history. Multiple contradictory explanatory models for the causation of cognitive deficits were reported.

The relationship between cognitive clusters and telomere length in bipolar-schizophrenia spectrum disorders

BACKGROUND

Schizophrenia and bipolar disorder are complex mental illnesses that are associated with cognitive deficits. There is considerable cognitive heterogeneity that exists within both disorders. Studies that cluster schizophrenia and bipolar patients into subgroups based on their cognitive profile increasingly demonstrate that, relative to healthy controls, there is a severely compromised subgroup and a relatively intact subgroup. There is emerging evidence that telomere shortening, a marker of cellular senescence, may be associated with cognitive impairments. The aim of this study was to explore the relationship between cognitive subgroups in bipolar-schizophrenia spectrum disorders and telomere length against a healthy control sample.

METHODS

Participants included a transdiagnostic group diagnosed with bipolar, schizophrenia or schizoaffective disorder (n = 73) and healthy controls (n = 113). Cognitive clusters within the transdiagnostic patient group, were determined using K-means cluster analysis based on current cognitive functioning (MATRICS Consensus Cognitive Battery scores). Telomere length was determined using quantitative PCRs genomic DNA extracted from whole blood. Emergent clusters were then compared to the healthy control group on telomere length.

RESULTS

Two clusters emerged within the patient group that were deemed to reflect a relatively intact cognitive group and a cognitively impaired subgroup. Telomere length was significantly shorter in the severely impaired cognitive subgroup compared to the healthy control group.

CONCLUSIONS

This study replicates previous findings of transdiagnostic cognitive subgroups and associates shorter telomere length with the severely impaired cognitive subgroup. These findings support emerging literature associating cognitive impairments in psychiatric disorders to accelerated cellular aging as indexed by telomere length.

Brain atrophy and cognitive decline in bipolar disorder: Influence of medication use, symptomatology and illness duration

Bipolar disorder (BPD) is a chronic condition characterized by recurrent episodes of mania and depression. To date, the association of biological and psychopathological processes in BPD has not been extensively studied on a cognitive and cortical basis at the same time. We investigated whether brain atrophy (in prefrontal, temporal and occipital cortices) was associated with cognitive, biological and clinical processes in patients with BPD and healthy controls (HCs). A total of 104 participants (56 with BPD) completed tasks that measured attention, memory, information processing speed, inhibitory control, visuospatial working memory and cognitive flexibility. In addition, structural brain scans were obtained using high-resolution MRI. Outcomes of the measurements were examined using robust multiple mediation analyses. BPD patients showed greater cortical atrophy across all regions of interest when compared to HCs, linked to cognitive decline. BPD patients had slower reaction times and markedly increased errors of commission on the tasks. The outcomes were significantly influenced by medication use, symptomatology and illness duration. The findings showcase the complexity of brain structures and networks as well as the physiological mechanisms underlying diverse BPD symptomatology and endophenotypes. These differences were pronounced in patients with BPD, motivating further investigations of pathophysiological mechanisms involved in brain atrophy and cognitive decline.

Empathy deficit in male patients with schizophrenia and its relationships with impulsivity and premeditated violence

Objective

To explore the pattern of empathy characteristics in male patients with schizophrenia (SCH) and to examine whether empathy deficit is associated with impulsivity and premeditated violence.

Methods

One hundred and fourteen male SCH patients were enrolled in this study. The demographic data of all patients were collected and the subjects were divided into two groups, namely, the violent group, including 60 cases, and the non-violent group, comprising 54 cases, according to the Modified Overt Aggression Scale (MOAS). The Chinese version of the Interpersonal Reactivity Index-C (IRI-C) was used to evaluate empathy and the Impulsive/Predicted Aggression Scales (IPAS) was employed to assess the characteristics of aggression.

Results

Among the 60 patients in the violent group, 44 patients had impulsive aggression (IA) and 16 patients had premeditated aggression (PM) according to the IPAS scale. In the violent group, the scores of the four subfactors of the IRI-C, i.e., perspective taking (PT), fantasy (FS), personal distress (PD), and empathy concern (EC), were significantly lower than in the non-violent group. Stepwise logistic regression showed that PM was independent influencing factor for violent behaviors in SCH patients. Correlation analysis revealed that EC of affective empathy was positively correlated with PM but not with IA.

Conclusion

SCH patients with violent behavior had more extensive empathy deficits compared with non-violent SCH patients. EC, IA and PM are independent risk factors of violence in SCH patients. Empathy concern is an important index to predict PM in male patients with SCH.

A comparison of neighbourhood level variation and risk factors for affective versus non-affective psychosis

BACKGROUND

Studies typically highlight area level variation in the incidence of non-affective but not affective psychoses. We compared neighbourhood-level variation for both types of disorder, and the specific effects of neighbourhood urbanicity and ethnic density, using Danish national registry data.

METHODS

Population based cohort (2,224,464 people) followed from 1980 to 2013 with neighbourhood exposure measured at age 15 and incidence modelled using multilevel Poisson regression.

RESULTS

Neighbourhood variation was similar for both disorders with an adjusted median risk ratio of 1.37 (95% CI 1.34-1.39) for non-affective psychosis and 1.43 (1.38-1.49) for affective psychosis. Associations with neighbourhood urbanicity differed: living in the most compared to the least urban quintile at age 15 was associated with a minimal increase in subsequent affective psychosis, IRR 1.13 (1.01-1.27) but a substantial increase in rates of non-affective psychosis, IRR 1.66 (1.57-1.75). Mixed results were found for neighbourhood ethnic density: for Middle Eastern migrants there was an increased average incidence of both affective, IRR 1.54 (1.19-1.99), and non-affective psychoses, 1.13 (1.04-1.23) associated with each decrease in ethnic density quintile, with a similar pattern for African migrants, but for European migrants ethnic density appeared to be associated with non-affective psychosis only.

CONCLUSIONS

While overall variation and the effect of neighbourhood ethnic density were similar for both types of disorder, associations with urbanicity were largely confined to non-affective psychosis. This may reflect differences in aetiological pathways although the mechanism behind these differences remains unknown.

Suicidal ideation in Chinese adults with schizophrenia: associations with neurocognitive function and empathy

BACKGROUND

Suicidal ideation is common among people diagnosed with schizophrenia spectrum disorders and may be related to neurocognitive, social cognitive, and clinical variables. This study aimed to investigate the relationships between suicidal ideation and both neurocognitive function and empathy.

METHODS

The sample for this cross-sectional study comprised 301 schizophrenic patients aged 18-44 years. All participants were administered the Beck Scale for Suicide Ideation-Chinese Version (BSI-CV), the Repeatable Battery for the Assessment of Neuropsychological Status (RBANS), the Interpersonal Reactivity Index (IRI), and the Positive and Negative Syndrome Scale (PANSS). The demographic and clinical data of the patients were also collected.

RESULTS

In total, 82 patients reported suicidal ideation. Compared to patients without suicidal ideation, patients with suicidal ideation showed significant differences in the IRI-Personal Distress subscale, PANSS-General Psychopathology symptom scores, and suicide attempts. Moreover, there were moderating effects of neurocognitive function and empathy on the relationship between suicide attempts and suicidal ideation.

CONCLUSIONS

These results indicate that the personal distress component of empathy, general psychopathology symptoms and suicide attempts are independent risk factors for suicidal ideation in Chinese adults with schizophrenia. Moreover, neurocognitive function may also be related to suicidal ideation through a moderating relationship. In order to reduce suicidal ideation among patients with schizophrenia, early screening of empathy and neurocognitive function is essential.

A consideration of the increased risk of schizophrenia due to prenatal maternal stress, and the possible role of microglia

Schizophrenia is caused by interaction of a combination of genetic and environmental factors. Of the latter, prenatal exposure to maternal stress is reportedly associated with elevated disease risk. The main orchestrators of inflammatory processes within the brain are microglia, and aberrant microglial activation/function has been proposed to contribute to the aetiology of schizophrenia. Here, we evaluate the epidemiological and preclinical evidence connecting prenatal stress to schizophrenia risk, and consider the possible mediating role of microglia in the prenatal stress-schizophrenia relationship. Epidemiological findings are rather consistent in supporting the association, albeit they are mitigated by effects of sex and gestational timing, while the evidence for microglial activation is more variable. Rodent models of prenatal stress generally report lasting effects on offspring neurobiology. However, many uncertainties remain as to the mechanisms underlying the influence of maternal stress on the developing foetal brain. Future studies should aim to characterise the exact processes mediating this aspect of schizophrenia risk, as well as focussing on how prenatal stress may interact with other risk factors.

Working memory heterogeneity from age 7 to 11 in children at familial high risk of schizophrenia or bipolar disorder- The Danish High Risk and Resilience Study

BACKGROUND

Despite the genetic overlap between bipolar disorder and schizophrenia, working memory impairments are mainly found in children of parents with schizophrenia. However, working memory impairments are characterized by substantial heterogeneity, and it is unknown how this heterogeneity develops over time. We used a data-driven approach to assess working memory heterogeneity and longitudinal stability in children at familial high risk of schizophrenia (FHR-SZ) or bipolar disorder (FHR-BP).

METHODS

Based on the performances on four working memory tasks by 319 children (FHR-SZ, N = 202, FHR-BP, N = 118) measured at age 7 and 11, latent profile transition analysis was used to test for the presence of subgroups, and the stability of subgroup membership over time. Population-based controls (VIA 7, N = 200, VIA 11, N = 173) were included as a reference group. The working memory subgroups were compared based on caregiver- and teacher ratings of everyday working memory function, and dimensional psychopathology.

RESULTS

A model with three subgroups characterized by different levels of working memory function (an impaired subgroup, a mixed subgroup, and an above average subgroup) best fitted the data. The impaired subgroup had the highest ratings of everyday working memory impairments and psychopathology. Overall, 98 % (N = 314) stayed in the same subgroup from age 7 to 11.

CONCLUSION

Persistent working memory impairments are present in a subset of children at FHR-SZ and FHR-BP throughout middle childhood. Attention should be given to these children, as working memory impairments influence daily life, and may serve as a vulnerability marker of transition to severe mental illness.

Potentially causal associations between placental DNA methylation and schizophrenia and other neuropsychiatric disorders

Increasing evidence supports the role of placenta in neurodevelopment and potentially, in the later onset of neuropsychiatric disorders. Recently, methylation quantitative trait loci (mQTL) and interaction QTL (iQTL) maps have proven useful to understand SNP-genome wide association study (GWAS) relationships, otherwise missed by conventional expression QTLs. In this context, we propose that part of the genetic predisposition to complex neuropsychiatric disorders acts through placental DNA methylation (DNAm). We constructed the first public placental cis-mQTL database including nearly eight million mQTLs calculated in 368 fetal placenta DNA samples from the INMA project, ran cell type- and gestational age-imQTL models and combined those data with the summary statistics of the largest GWAS on 10 neuropsychiatric disorders using Summary-based Mendelian Randomization (SMR) and colocalization. Finally, we evaluated the influence of the DNAm sites identified on placental gene expression in the RICHS cohort. We found that placental cis-mQTLs are highly enriched in placenta-specific active chromatin regions, and useful to map the etiology of neuropsychiatric disorders at prenatal stages. Specifically, part of the genetic burden for schizophrenia, bipolar disorder and major depressive disorder confers risk through placental DNAm. The potential causality of several of the observed associations is reinforced by secondary association signals identified in conditional analyses, regional pleiotropic methylation signals associated to the same disorder, and cell type-imQTLs, additionally associated to the expression levels of relevant immune genes in placenta. In conclusion, the genetic risk of several neuropsychiatric disorders could operate, at least in part, through DNAm and associated gene expression in placenta.

Psychotic disorders as a framework for precision psychiatry

People with psychotic disorders can show marked interindividual variations in the onset of illness, responses to treatment and relapse, but they receive broadly similar clinical care. Precision psychiatry is an approach that aims to stratify people with a given disorder according to different clinical outcomes and tailor treatment to their individual needs. At present, interindividual differences in outcomes of psychotic disorders are difficult to predict on the basis of clinical assessment alone. Therefore, current research in psychosis seeks to build models that predict outcomes by integrating clinical information with a range of biological measures. Here, we review recent progress in the application of precision psychiatry to psychotic disorders and consider the challenges associated with implementing this approach in clinical practice.

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.

Brain Morphological Characteristics of Cognitive Subgroups of Schizophrenia-Spectrum Disorders and Bipolar Disorder: A Systematic Review with Narrative Synthesis

Despite a growing body of research, there is yet to be a cohesive synthesis of studies examining differences in brain morphology according to patterns of cognitive function among both schizophrenia-spectrum disorder (SSD) and bipolar disorder (BD) individuals. We aimed to provide a systematic overview of the morphological differences-inclusive of grey and white matter volume, cortical thickness, and cortical surface area-between cognitive subgroups of these disorders and healthy controls, and between cognitive subgroups themselves. An initial search of PubMed and Scopus databases resulted in 1486 articles of which 20 met inclusion criteria and were reviewed in detail. The findings of this review do not provide strong evidence that cognitive subgroups of SSD or BD map to unique patterns of brain morphology. There is preliminary evidence to suggest that reductions in cortical thickness may be more strongly associated with cognitive impairment, whilst volumetric deficits may be largely tied to the presence of disease.

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.

Neurocognitive Subgroups in Children at Familial High-risk of Schizophrenia or Bipolar disorder: Subgroup Membership Stability or Change From Age 7 to 11-The Danish High Risk and Resilience Study

BACKGROUND AND HYPOTHESIS

Subgroups with distinct levels of neurocognitive functioning exist in children of parents with schizophrenia or bipolar disorder. However, studies investigating the temporal stability of subgroup membership are currently lacking. We hypothesized that a minority of children at familial high-risk of schizophrenia (FHR-SZ) or bipolar disorder (FHR-BP) would transition to a different neurocognitive subgroup from age 7 to 11 and that most transitions would be to a more impaired subgroup.

STUDY DESIGN

Latent profile analysis was used to identify subgroups at two assessments (age 7 and 11) based on the performance of 320 children at FHR-SZ or FHR-BP across eight neurocognitive functions. Temporal stability in subgroup membership was evaluated with latent profile transition analysis. Population-based controls (age 7, n = 199; age 11, n = 178) were included as a reference group. Children transitioning to a more impaired subgroup were compared with nontransitioning children on sex, FHR-status, global functioning, and psychopathology.

STUDY RESULTS

At both assessment points, we identified three subgroups based on neurocognitive performance: a moderately-severely impaired, a mildly impaired, and an above-average subgroup. A total of 12.8% of children transitioned to a different subgroup, of which the majority (85.2%) moved to a more impaired subgroup. Parental diagnosis of schizophrenia, but neither parental diagnosis of bipolar disorder, global functioning at age 7, psychopathology, nor sex significantly differentiated children transitioning to a more impaired subgroup from nontransitioning children.

CONCLUSIONS

During pre-adolescence, neurocognitive developmental lag is associated with being at FHR-SZ. Close attention to these children's neurocognitive development is indicated.

Mental disorders in preadolescent children at familial high-risk of schizophrenia or bipolar disorder - a four-year follow-up study: The Danish High Risk and Resilience Study, VIA 11: The Danish High Risk and Resilience Study, VIA 11

BACKGROUND

Children at familial high-risk of schizophrenia and bipolar disorder have an elevated prevalence of mental disorders but studies of children within a narrow age range are lacking and there are few conjoint studies of these two groups. Knowledge on their mental health is important for prevention and early intervention.

METHODS

The authors examined mental disorders and global functioning in children at familial high-risk of schizophrenia (FHR-SZ) and bipolar disorder (FHR-BP) compared with population-based controls. In a longitudinal cohort study, 450 children (FHR-SZ, n = 171; FHR-BP, n = 104; controls, n = 175), were assessed for Axis I disorders at baseline and four-year follow-up (mean age 11.9, SD 0.2) with the Kiddie Schedule for Affective Disorders and Schizophrenia for School-Age Children and for global functioning with Children's Global Assessment Scale.

RESULTS

Cumulative incidence of Any Axis I disorder was elevated by age 11 in children at FHR-SZ (54.4%, OR 3.0, 95% CI 1.9-4.7, p < .001) and children at FHR-BP (52.9%, OR 2.8, 95% CI 1.7-4.7, p < .001) compared with controls (28.6%). Children at FHR-SZ and FHR-BP had higher rates of affective disorders (OR 4.4, 95% CI 1.4-13.5, p = .009; OR 5.1, 95% CI 1.6-16.4, p = .007), anxiety disorders (OR 2.1, 95% CI 1.1-4.0, p = .02; OR 3.0, 95% CI 1.5-6.1, p = .002), and stress and adjustment disorders (OR 3.3, 95% CI 1.4-7.5, p = .006; OR 5.3, 95% CI 2.2-12.4, p < .001). Disruptive behavior disorders (OR 2.8, 95% CI 1.0-7.3, p = .04) and ADHD (OR 2.9, 95% CI 1.6-5.3, p < .001) were elevated in children at FHR-SZ. Both FHR groups had lower global functioning than controls. Cumulative incidence of disorders increased equally across the three groups from early childhood to preadolescence and level of functioning did not change differentially.

CONCLUSIONS

Children at FHR-SZ and FHR-BP have an elevated prevalence of mental disorders and poorer functioning than controls. Vulnerability in children at FHR manifests early and remains stable throughout childhood. Early attention toward their mental health and identification of those in need of intervention is warranted.

Transmission of intelligence, working memory, and processing speed from parents to their seven-year-old offspring is function specific in families with schizophrenia or bipolar disorder

BACKGROUND

Prior studies have shown high heritability estimates regarding within-function transmission of neurocognition, both in healthy families and in families with schizophrenia but it remains an open question whether transmission from parents to offspring is function specific and whether the pattern is the same in healthy families and families with schizophrenia or bipolar disorder. We aimed to characterize the transmission of intelligence, processing speed, and verbal working memory functions from both biological parents to their 7-year-old offspring in families with parental schizophrenia, bipolar disorder, and population-based control parents.

METHODS

The population-based cohort consists of 7-year-old children with one parent diagnosed with schizophrenia (n = 186), bipolar disorder (n = 114), and of parents without schizophrenia or bipolar disorder (n = 192). Children and both parents were assessed using identical, age-relevant neurocognitive tests of intelligence, verbal working memory, and processing speed.

RESULTS

In multiple regression analyses children's intelligence, verbal working memory, and processing speed scores were significantly associated with the corresponding parental cognitive function score. All associations from parents to offspring across functions were non-significant. No significant parental cognitive function by group interaction was observed.

CONCLUSION

Transmissions of intelligence, processing speed, and verbal working memory from parents to offspring are function specific. The structure of transmission is comparable between families with schizophrenia, families with bipolar disorder and families without these disorders.

Heterogeneity of social cognitive and language functions in children at familial high-risk of severe mental illness; The Danish High Risk and Resilience Study VIA 7

Cognitive heterogeneity characterizes individuals with schizophrenia and bipolar disorder; however, little is known of cognitive heterogeneity within young children at familial high-risk of schizophrenia or bipolar disorder. This study aimed to investigate heterogeneity across social cognitive and language functions in children at familial high-risk of schizophrenia or bipolar disorder, i.e. severe mental illness (FHR-SMI). This may help designate subgroups in need of intervention initiatives. A data-driven, hierarchical cluster analysis was applied across a sample of 322 children at FHR-SMI (FHR-SZ, n = 200; FHR-BP, n = 120) on measures of Theory of Mind, facial emotion recognition, social cognitive processing speed, receptive and pragmatic language. We examined differences between subgroups as well as differences between subgroups and a control group. Exploratively, the subgroups were compared in terms of social responsiveness and global functioning. A Typical-High Functioning Subgroup with intact social cognitive and language functioning (34.5%), a Mildly Impaired Subgroup with selective impairments in explicit Theory of Mind and language functioning (58.7%), and a Significantly Impaired Subgroup with social cognitive and language functioning impairments (6.8%) were identified. The subgroups differed significantly from each other and overall compares to the controls. The Significantly and Mildly Impaired Subgroups presented with poorer social responsiveness and global functioning than the Typical-High Functioning Subgroup. In young children with FHR-SMI, three subgroups with relatively homogeneous social cognitive and language functioning profiles were observed. Only a small proportion of children at FHR-SMI displayed large social cognitive and language functioning impairments in middle childhood.

Serum levels of olanzapine are associated with acute cognitive effects in bipolar disorder

Bipolar (BPD) patients have deficits in cognition, but there are still controversies about the effects of some medications on their cognitive performance. Here, we investigated the relationship between cognition in terms of executive functions, memory, and attention in both first-episode medication-naive BPD patients and BPD patients taking olanzapine. Forty-one healthy controls, 40 unmedicated drug-naive BPD patients, and 34 BPD patients who took only olanzapine were recruited for the study. Cognitive performance was assessed using the Flanker test, Stroop test, and Corsi-block test. Bayesian multivariate regression analysis was run considering maximum robustness to avoid bias and to predict the outcomes. Our results revealed that unmedicated medication-naive BPD patients performed worse than healthy controls and the olanzapine group in some tasks. Additionally, BPD patients who took olanzapine had better cognitive performance than healthy controls and unmedicated BPD patients. The acute cognitive effects were predicted by olanzapine dosage and serum levels (i.e., large effects). The potential pro-cognitive effects of olanzapine in BPD patients should be carefully interpreted by considering various other clinical variables. We expect that our findings will contribute to further research in this area, with the goal of helping other researchers, patients, and the population.

Neurocognitive heterogeneity in 7-year-old children at familial high risk of schizophrenia or bipolar disorder: The Danish high risk and resilience study - VIA 7

BACKGROUND

Studies of neurocognitive heterogeneity in young children at familial high-risk of bipolar disorder (FHR-BP) or schizophrenia (FHR-SZ) are important to investigate inter-individual neurocognitive differences. We aimed to identify neurocognitive subgroups, describe prevalence of FHR-BP or FHR-SZ children herein, and examine risk ratios (RR) compared with controls.

METHODS

In a population-based cohort of 514 7-year-old children (197 FHR-SZ, 118 FHR-BP, and 199 matched controls) we used hierarchical cluster analyses to identify subgroups across 14 neurocognitive indices.

RESULTS

Three neurocognitive subgroups were derived: A Mildly Impaired (30%), Typical (51%), and Above Average subgroup (19%). The Mildly Impaired subgroup significantly underperformed controls (Cohen d = 0.11-1.45; Ps < 0.001) except in set-shifting (P = .84). FHR-SZ children were significantly more prevalent in the Mildly Impaired subgroup; FHR-BP children were more so in the Above Average subgroup (X² (2, N = 315) = 9.64, P < .01). 79.7% FHR-BP and 64.6% FHR-SZ children demonstrated typical or above average neurocognitive functions. Neurocognitive heterogeneity related significantly to concurrent functioning, psychopathology severity, home environment adequacy, and polygenic scores for schizophrenia (Ps <. 01). Compared with controls, FHR-SZ and FHR-BP children had a 93% (RR, 1.93; 95% CI, 1.40-2.64) and 8% (RR, 1.08; 95% CI, 0.71-1.66) increased risk of Mildly Impaired subgroup membership.

LIMITATIONS

Limitations include the cross-sectional design and smaller FHR-BP sample size.

CONCLUSIONS

Identification of neurocognitive heterogeneity in preadolescent children at FHR-BP or FHR-SZ may ease stigma and enable pre-emptive interventions to enhance neurocognitive functioning and resilience to mental illness in the impaired sub-population.

Neurocognition, functional outcome, and quality of life in remitted and non-remitted schizophrenia: A comparison with euthymic bipolar I disorder and a control group

There are discrepancies about if the severity of the symptomatology in schizophrenia is related to neurocognitive performance, functional outcome, and quality of life (QoL). Also, there are controversial data about the comparison between euthymic bipolar patients and different subgroups of schizophrenia in neurocognition, functioning, and QoL level. The present study aimed to compare the neurocognitive performance, functional outcome, and QoL of remitted and non-remitted patients with SC with respect to a group of euthymic patients with BD, and a control group. It included 655 subjects: 98 patients with schizophrenia in remission (SC-R), 184 non-remitted patients with schizophrenia (SC-NR), 117 euthymic patients with bipolar I disorder (BD), and 256 healthy subjects. A comprehensive clinical, neurocognitive (six cognitive domains), functional, and QoL assessment was carried out. Remission criteria of Andreasen were used to classify schizophrenia patients as remitted or non-remitted. Compared with control subjects all groups of patients showed impaired neurocognitive performance, functioning and QoL. SC-R patients had an intermediate functioning between control subjects and SC-NR, all at a neurocognitive, functional, or QoL level. There were no significant differences between SC-R and BD. These results suggest that reaching clinical remission is essential to achieve a better level of psychosocial functioning, and QoL. Likewise, the results of this study suggest that euthymic patients with bipolar disorder and patients with schizophrenia in remission are comparable at the neurocognitive and functional levels, which might have implications in the pathophysiology of both disorders.

History of ECT in Schizophrenia: From Discovery to Current Use

Eighty years ago, schizophrenia was the first indication for electroconulsive therapy (ECT), and likewise ECT was one of the first treatments used for schizophrenia. This paper presents the history of ECT in the treatment of schizophrenia and its evolution, from it's discovery in the 20th century, which is an example of empiricism with a sequence of "shock" therapies. Following this discovery, the use ECT in schizophrenia has been in expansion during several decades, in a context of lack of efficacy of the treatment in schizophrenia. Then, after World War II and the derivative use of ECT in Germany, the use of ECT has decline during several decades. However, in the last decades, the use of ECT in schizophrenia has reemerged. Indeed, among patients in schizophrenia, rates of resistance to treatment have always been and still are high. In 2017, the concept of "ultra-treatment resistant schizophrenia" was defined when clozapine was tried and failed; and ECT, that had been long since abandoned in the treatment of schizophrenia until recent renewed interest, has emerged especially concerning the add-on of ECT to clozapine. However, ECT remains highly stigmatized and underutilized. This article looks at the history of the practice of ECT in schizophrenia with a historical and clinical approach and makes connections between the history of the treatment and its influence on its current recommendation and practice.

Working memory deficits in children with schizophrenia and its mechanism, susceptibility genes, and improvement: A literature review

The negative influence on the cognitive ability of schizophrenia is one of the issues widely discussed in recent years. Working memory deficits are thought to be a core cognitive symptom of schizophrenia and lead to poorer social functions and worse academic performance. Previous studies have confirmed that working memory deficits tend to appear in the prodromal phase of schizophrenia. Therefore, considering that children with schizophrenia have better brain plasticity, it is critical to explore the development of their working memory. Although the research in this field developed gradually in recent years, few researchers have summarized these findings. The current study aims to review the recent studies from both behavior and neuroimaging aspects to summarize the working memory deficits of children with schizophrenia and to discuss the pathogenic factors such as genetic susceptibility. In addition, this study put forward some practicable interventions to improve cognitive symptoms of schizophrenia from psychological and neural perspectives.

Executive functions in 7-year-old children of parents with schizophrenia or bipolar disorder compared with controls: The Danish High Risk and Resilience Study-VIA 7, a population-based cohort study

Cognitive impairments are strongly associated with schizophrenia (SZ) and bipolar disorder (BP) with executive functions (EF) impairments as a likely key feature. Studies of everyday behavior rated EF in young children at familial high risk of SZ (FHR-SZ) are scarce and, to our knowledge, non-existent in young children at familial high risk of BP (FHR-BP). We aimed to compare everyday behavior-rated EF of FHR-SZ, FHR-BP, and control children. A nationwide population-based cohort of 522 7-year-old children with parents diagnosed with either SZ (N = 202) or BP (N = 120) and matched controls (N = 200) were recruited using the Danish national registries. The children's EF were assessed with the Behavior Rating Inventory of Executive Functions questionnaire rated by primary caregivers and teachers. According to primary caregiver assessments, FHR-SZ children displayed widespread EF impairments and had an odds ratio of 3.7 (2.0-6.9) of having clinically significant global EF impairments compared to controls. FHR-BP children were most severely impaired regarding EF related to emotional control and had an odds ratio of 2.5 (1.2-5.1) of clinically significant global EF impairments compared to controls. Teacher assessments were overall comparable to primary caregiver assessments but teachers rated more difficulties in the FHR-SZ group than primary caregivers. Already at age 7, children with a parental history of SZ or BP displayed significant impairments of EF in everyday-life situations. FHR-SZ children displayed widespread significant impairments of EF, whereas FHR-BP children were most severely impaired on emotional control. Clinicians should be aware of potential EF impairments in FHR children.

Abnormal Network Properties and Fiber Connections of DMN across Major Mental Disorders: A Probability Tracing and Graph Theory Study

The default mode network (DMN) is related to brain functions and its abnormalities were associated with mental disorders' pathophysiology. To further understand the common and distinct DMN alterations across disorders, we capitalized on the probability tracing method and graph theory to analyze the role of DMN across three major mental disorders. A total of 399 participants (156 schizophrenia [SCZ], 90 bipolar disorder [BP], 58 major depression disorder [MDD], and 95 healthy controls [HC]) completed magnetic resonance imaging (MRI)-scanning, clinical, and cognitive assessment. The MRI preprocessing of diffusion-tensor-imaging was conducted in FMRIB Software Library and probabilistic fiber tracking was applied by PANDA. This study had three main findings. First, patient groups showed significantly lower cluster coefficient in whole-brain compared with HC. SCZ showed significantly longer characteristic path compared with HC. Second, patient groups showed inter-group specificity in abnormalities of DMN connections. Third, SCZ was sensitive to left_medial_superior_frontal_gyrus (L_SFGmed)-right_anterior_cingulate_gyrus (R_ACG) connection relating to positive symptoms; left_ACG-right_ACG connection was the mania's antagonistic factor in BP. This trans-diagnostic study found disorder-specific structural abnormalities in the fiber connection of R_SFGmed-L_SFGmed-R_ACG_L_ACG within DMN, where SCZ showed more disconnections compared with other disorders. And these connections are diagnosis-specifically correlated to phenotypes. The current study may provide further evidence of shared and distinct endo-phenotypes across psychopathology.

A network analysis and empirical validation of executive deficits in patients with psychosis and their healthy siblings

BACKGROUND

Psychopathological symptoms and cognitive impairment are core features of patients with psychotic disorders. Executive dysfunctions are commonly observed and typically assessed using tests like the Wisconsin Card Sorting Test (WCST). However, the structure of executive deficits remains unclear, and the underlying processes may be different. This study aimed to explore and compare the network structure of WCST measures in patients with psychosis and their unaffected siblings and to empirically validate the resulting network structure of the patients.

METHODS

The subjects were 298 patients with a DSM 5 diagnosis of a psychotic disorder and 89 of their healthy siblings. The dimensionality and network structure of the WCST were examined by means of exploratory graph analysis (EGA) and network centrality parameters.

RESULTS

The WCST network structure comprised 4 dimensions: perseveration (PER), inefficient sorting (IS), failure to maintain set (FMS) and learning (LNG). The patient and sibling groups showed a similar network structure, which was reliably estimated. PER and IS showed common and strong associations with antecedent, concurrent and outcome validators. The LNG dimension was also moderately associated with these validators, but FMS did not show significant associations.

CONCLUSIONS

Four cognitive processes underlying WCST performance were identified by the network analysis. PER, IS and LNG were associated with and shared common antecedent, concurrent and outcome validators, while FMS was not associated with external validators. These four underlying dysfunctions might help disentangle the neurofunctional basis of executive deficits in psychosis.

The dopamine D2 agonist quinpirole impairs frontal mismatch responses to sound frequency deviations in freely moving rats

Aim

A reduced mismatch negativity (MMN) response is a promising electrophysiological endophenotype of schizophrenia that reflects neurocognitive impairment. Dopamine dysfunction is associated with symptoms of schizophrenia. However, whether the dopamine system is involved in MMN impairment remains controversial. In this study, we investigated the effects of the dopamine D2‐like receptor agonist quinpirole on mismatch responses to sound frequency changes in an animal model.

Methods

Event‐related potentials were recorded from electrocorticogram electrodes placed on the auditory and frontal cortices of freely moving rats using a frequency oddball paradigm consisting of ascending and equiprobable (ie, many standards) control sequences before and after the subcutaneous administration of quinpirole. To detect mismatch responses, difference waveforms were obtained by subtracting nondeviant control waveforms from deviant waveforms.

Results

Here, we show the significant effects of quinpirole on frontal mismatch responses to sound frequency deviations in rats. Quinpirole delayed the frontal N18 and P30 mismatch responses and reduced the frontal N55 MMN‐like response, which resulted from the reduction in the N55 amplitude to deviant stimuli. Importantly, the magnitude of the N55 amplitude was negatively correlated with the time of the P30 latency in the difference waveforms. In contrast, quinpirole administration did not clearly affect the temporal mismatch responses recorded from the auditory cortex.

Conclusion

These results suggest that the disruption of dopamine D2‐like receptor signaling by quinpirole reduces frontal MMN to sound frequency deviations and that delays in early mismatch responses are involved in this MMN impairment.

The subcutaneous administration of quinpirole delayed early mismatch response latencies and reduced a late MMN‐like response amplitude recorded from the frontal cortex but had no effect on those recorded from the auditory cortex. These observations suggest that increased dopamine D2‐like receptor signaling impairs MMN generation to sound frequency changes in the frontal cortex and that the neurochemical mechanisms of MMN vary according to the cortical area. As MMN is associated with cognitive function, these new findings may help develop treatment modalities for cognitive dysfunctions in schizophrenia.

Performance on the Wechsler Adult Intelligence Scale (WAIS) in Japanese patients with bipolar and major depressive disorders in euthymic and depressed states

AIM

This study aimed to examine the cognitive performance of patients with bipolar disorder (BD) stratified by illness phase compared to that of patients with major depressive disorder (MDD) and healthy controls.

METHODS

Participants were 139 patients with BD (55 euthymic and 84 depressed), 311 patients with MDD (88 euthymic and 223 depressed), and 386 healthy controls who underwent the Wechsler Adult Intelligence Scale-Revised or the Third Edition. They were non-elderly Japanese individuals with normal estimated premorbid intelligence quotient (IQ; >90), group-matched for age, sex, and premorbid IQ.

RESULTS

The depressed BD group showed significantly lower scores on verbal IQ, performance IQ, full-scale IQ, and three group indexes of perceptual organization, working memory, and processing speed when compared with healthy controls (all P < 0.001). All IQs and working memory index were also significantly lower than those of the depressed MDD group. The depressed MDD group scored significantly lower than controls in performance IQ (P < 0.001), full-scale IQ, and only in the index of processing speed (P < 0.001). The euthymic BD group scored significantly lower than controls in performance IQ (P = 0.004), whereas the euthymic MDD group scored significantly lower than controls only in processing speed (P = 0.030).

CONCLUSION

Patients with BD appear to have global and more intense cognitive impairments in depressed states compared with those with MDD whose impairments seem to be apparent only in processing speed in the Wechsler Adult Intelligence Scale. Attenuated impairments appear to exist in euthymic states of both patients.

Cognitive heterogeneity in the offspring of patients with schizophrenia or bipolar disorder: a cluster analysis across family risk

BACKGROUND

Neurocognitive impairment is considered to lie on a continuum of severity across schizophrenia (SZ) and bipolar disorder (BP), possibly reflecting a gradient of neurodevelopmental load. Cluster analyses have identified different levels of impairment across the two disorders, from none to widespread and severe. We for the first time used this approach to examine cognitive function pooling together children and adolescents at familial risk of SZ or BP.

METHODS

220 participants, 49 offspring of individuals with schizophrenia (SZO), 90 offspring of individuals with bipolar disorder (BPO) and 81 offspring of healthy control parents (HC), aged 6 to 17 years, underwent a comprehensive clinical and cognitive assessment. Cognitive measures were used to group SZO and BPO using K-means clustering. Cognitive performance within each of the clusters was compared to that of HC and clinical variables were compared between clusters.

RESULTS

We identified three cognitive subgroups: a moderate impairment group, a mild impairment group, and a cognitively intact group. Both SZO and BPO were represented in each of the clusters, yet not evenly, with a larger proportion of the SZO in the moderately impaired cluster, but also a subgroup of BPO showing moderate cognitive dysfunction.

LIMITATIONS

Participants have yet to reach the age of onset for the examined disorders.

CONCLUSIONS

The findings point to a range of neurodevelopmental loadings across youth at familial risk of both SZ and BP. They have therefore important implications for the stratification of cognitive functioning and the possibility to tailor interventions to individual levels of impairment.

Decision making and its associations to neurocognitive functions, psychopathology, and the home environment in seven-year-old children at familial high risk of schizophrenia or bipolar disorder: The Danish High Risk and Resilience Study VIA 7

BACKGROUND

Slower and suboptimal decision making has been identified in adults with schizophrenia and bipolar disorder. Owing to the limited evidence on decision making in first-degree relatives, we aimed to investigate, whether alterations in decision making are present in young children at familial high risk of bipolar disorder or schizophrenia.

METHODS

In this population-based cohort study we assessed decision making in 197 children at familial high risk of schizophrenia (FHR-SZ), 115 children at familial high risk of bipolar disorder (FHR-BP), and 190 controls aged seven using the Cambridge Gambling Task. Potential associations to neurocognition, psychopathology, and the home environment were investigated.

RESULTS

Children at FHR-SZ or FHR-BP displayed intact decision making. Quality of decision making showed significant but weak cross-sectional associations to neurocognition and adequacy of the home environment. Associations to aspects of executive functions and the home environment differed across groups.

LIMITATIONS

Due to the cross-sectional nature of this study, the predictive value of efficient and inefficient decision making remains to be investigated in planned follow-up studies of this cohort.

CONCLUSIONS

Young children at FHR-SZ or FHR-BP do not differ from controls in decision making efficacy, which does not appear to be an early risk marker of bipolar disorder or schizophrenia. Decision making is weakly associated to neurocognition and the home environment, but not to general intelligence or psychopathology.

Development of visual attention from age 7 to age 12 in children with familial high risk for schizophrenia or bipolar disorder

BACKGROUND

Children with familial high risk of schizophrenia (FHR-SZ) or bipolar disorder (FHR-BP) are at increased risk of developing similar disorders and show cognitive deficits during childhood. The aim of this paper is to investigate visual attention and its developmental trajectories in children with FHR-SZ and with FHR-BP to increase our knowledge about potential cognitive endophenotypes of these two disorders.

METHODS

We compared the performance of 89 children with FHR-SZ (N = 32), FHR-BP (N = 22), and population-based controls (PBC, N = 35) at age 7 to that at age 12 as well as including 133 12-year-old children with FHR-SZ (N = 50), FHR-BP (N = 43) and PBC (N = 40) to investigate visual attention, as part of the Danish High Risk and Resilience Study. We used the TVA-based whole report paradigm, based on the Bundesen's Theory of Visual Attention (TVA) to investigate visual attention.

RESULTS

Children with FHR-SZ that showed deficits in visual processing speed at age 7 improved to a level that was not significantly different from controls at age 12. All children improved over time. We found no attentional deficits in FHR children at age 12.

CONCLUSIONS

On visual attention, children with FHR-SZ did not show developmental deficits or lags and, together with children with FHR-BP, they develop similarly to control children between age 7 to age 12. This emphasizes the potential of beneficial neuroplastic changes in cognitive deficits found at younger ages in children with FHR-SZ. It also highlights the importance of identifying and characterizing cognitive developmental trajectories of high-risk children and provides hope that visual attention may develop appropriately in these groups.

Neurocognitive functioning in bipolar disorder: What we know and what we don’t

Introduction: This narrative review of systematic reviews and meta-analyses aims at compiling available evidence in various aspects of neurocognitive functioning in Bipolar Disorder (BD).

Methods: We conducted a MEDLINE literature search and identified 38 relevant systematic reviews and metaanalyses.

Results: Current evidence suggests that BD is associated with cognitive impairment across multiple domains and during all clinical states. However, there is a considerable cognitive heterogeneity within BD, which cannot be explained by clinical subtypes, and the pattern of neurocognitive impairment in BD overlaps with other psychiatric conditions such as major depression and schizophrenia. Residual depressive symptoms, poor clinical course and higher number of manic episodes may negatively impact cognitive performance, which is a major predictor of general functioning in BD. Evidence from available prospective studies does not support the notion of progressive cognitive decline in BD while some evidence exists to suggest patients may show some improvements in cognitive functioning following the first manic episode. Furthermore, a subset of patients may show premorbid cognitive abnormalities that could signal an early neurodevelopmental aetiology. Preliminary findings from small studies identify potential pro-cognitive effects of Cognitive Remediation, erythropoietin, intranasal insulin, lurasidone, mifepristone, repetitive Transcranial Magnetic Stimulation and transcranial Direct Current Stimulation in BD.

Discussion: Longitudinal studies in high-risk individuals can provide a better understanding of the development and progression of neurocognitive impairment in BD. Largescale randomised control trials are needed to compare the pro-cognitive efficacy of various pharmacological and non-pharmacological interventions in different cognitive subgroups of patients at different stages of BD.

The MATRICS Consensus Cognitive Battery: Psychometric Properties of the Chinese Version in Young Patients With Major Depression Disorder

Background: Young patients with major depressive disorder are also associated with cognitive deficits. The development of an accurate and effective battery to measure cognitive impairment in young patients with major depressive disorder (Y-MDD) is necessary for both research and clinical practice. This study was designed to test the psychometric properties of the Measurement and Treatment Research to Improve Cognition in Schizophrenia (MATRICS) Consensus Cognitive Battery (MCCB) in Y-MDD. Method: Fifty Y-MDD patients, 38 euthymic young patients with bipolar disorder (Y-BD), and 51 healthy teenagers were recruited. The MCCB and the Montreal Cognitive Assessment (MoCA) were administered to assess cognitive impairment at baseline. The MCCB was also assessed 2 weeks later in Y-MDD patients. All subjects were between the ages of 13 and 24 years. Result: In the current study, cognitive impairment was greater in Y-BD patients than in Y-MDD patients in some domains. The MCCB has good internal consistency and reliability in Y-MDD patients. The Pearson correlation coefficients for retest reliability were good. Our findings also revealed an acceptable correlation between the MCCB and the MoCA, indicating good concurrent validity of the MCCB. Furthermore, exploratory factor analysis of the MCCB in Y-MDD patients revealed five domains with acceptable internal structures. Conclusion: The MCCB has acceptable psychometric properties and is a sensitive battery of cognitive impairment in Y-MDD patients. In the future, additional studies need to be carried out with larger samples while controlling for the use of psychotropic medications and antidepressants to validate the findings of the present study.

Neuropsychological development in the child and adolescent offspring of patients diagnosed with schizophrenia or bipolar disorder: A two-year follow-up comparative study

There has been growing scientific evidence in recent years that schizophrenia and bipolar disorder share clinical, cognitive, neuroimaging and genetic characteristics. This overlap might also be present in their offspring, who have an increased risk of developing both disorders. Comparing the characteristics of these samples may have important implications for understanding etiological processes. This study aimed to assess the development of cognitive functions over two years in a sample of child and adolescent offspring of patients diagnosed with schizophrenia (SZoff) or bipolar disorder (BDoff), comparing them with a community control group (CCoff).

METHODS

90 BDoff, 41 SZoff and 107 CCoff aged between 6 and 17 years were included at baseline. At the two-year follow-up, 84.9% of the sample was re-assessed (78 BDoff, 32 SZoff and 92 CCoff). All subjects were assessed with a comprehensive neuropsychological test battery at baseline and at the two-year follow-up to evaluate: intelligence quotient, working memory, processing speed, verbal memory and learning, visual memory, executive functions and sustained attention.

RESULTS

Processing speed, verbal memory and executive functions showed different developmental patterns among the SZoff, BDoff and CCoff groups. The SZoff group maintained baseline performances in the three variables over time, while the BDoff group presented improved processing speed and executive functioning and the CCoff group showed improvements in verbal memory and executive functions at follow-up.

CONCLUSIONS

These findings suggest that the development of some cognitive functions might differ between child and adolescent SZoff and BDoff, indicating different trajectories during neurodevelopment.

Relational memory in the early stage of psychotic bipolar disorder

Relational memory is impaired in psychotic disorders. In non-affective psychotic disorders, relational memory deficits are present in the early stage of illness and become more pronounced in the chronic stage. Previous studies have demonstrated cognitive deficits in early-stage psychotic bipolar disorder, but it is unclear whether relational memory is impaired. We examined relational memory using a face-scene binding task in early-stage psychotic bipolar disorder patients (n = 33) and compared their performance with healthy control (n = 40) and early-stage non-affective psychosis participants (n = 40). During training, participants learned to associate faces with background scenes. During testing, participants viewed a scene overlaid by three faces and were asked to recall the matching face. Relational memory was assessed indirectly using eye movements and explicitly using forced-choice recognition. Preferential viewing of the matching face, as captured by overall proportion of viewing and viewing across time, was significantly lower in psychotic bipolar disorder than in the healthy control group. However, preferential viewing of the matching face in psychotic bipolar disorder was significantly better than in non-affective psychosis. These findings provide novel evidence that relational memory in patients with early-stage psychotic bipolar disorder is intermediate between healthy control and early-stage non-affective psychosis subjects.

Predictive value of oxidative stress biomarkers in drug‑free patients with schizophrenia and schizo-affective disorder

Several studies have suggested that oxidative stress may represent one of the primary etiological mechanisms of schizophrenia (SZ) and schizoaffective disorder (SAD) which can be targeted by therapeutic intervention. The present study was conducted over a period of 24 months, between June 2016 and June 2018. All enrolled subjects were Tunisian, forty five drug‑free male patients with SZ (mean age: 37.6 years), twenty one drug‑free male patients with SAD (mean age: 28.8 years) and hundred and one age and gender matched controls (mean age: 34.2 years) were enrolled in the study. Plasma reduced glutathione (GSH) and Total thiols levels were significantly decreased in patients compared to controls (respectively p<0.001; p=0.050). In addition, malondialdehyde (MDA), advanced oxidation protein products (AOPP) and protein carbonyls (PC) concentrations and glutathione peroxidase (GSH-Px) activity were significantly increased in patients compared to controls (p<0.001; p<0.001; p<0.001 and p=0.003 respectively). The binary logistic regression analysis revealed that MDA, AOPP, PC and GSH-Px could be considered as independent risk factors for SZ and SAD. When using ROC analysis, a remarkable increase in the area under the curve (AUC) with higher sensitivity (Se) and specificity (Sp) for MDA, AOPP, PC and GSH-Px combined markers was observed. The present study indicated that the identification of the predictive value of this four-selected biomarkers related to oxidative stress in drug free patients should lead to a better identification of the etiological mechanism of SZ or SAD.

Italian Validation of the Screen for Cognitive Impairment in Psychiatry

Cognitive impairments have profound implications for the management of severe mental disorders; however, they are rarely assessed in everyday clinical practice due to constraints in time, resource and expertise. Novel and short instruments, such as the Screen for Cognitive Impairment in Psychiatry (SCIP), which overcome such limitations are greatly needed. The study aims to assess the validity and reliability, among healthy subjects, of the Italian translation of the SCIP, a brief, accessible tool to detect cognitive impairments among individuals suffering from mental disorders, as the first step to validate the instrument in clinical settings. One-hundred and twenty healthy subjects completed two of the three alternative forms of the SCIP. Cronbach Alpha (0.70) supported the reliability of the SCIP scores. Correlation coefficients supported the test-retest reliability of the tool. Learning effects were observed despite the use of alternative forms. Factor analysis indicated a two-factor solution explaining 55.4% of the total variance: the first factor ("memory") loading for VLT-I and VLT-D and less for WMT; the second factor ("executive function") loading for VFT and PST and less for WMT. The study proved the validity and reliability of the Italian version of the SCIP as a reliable and simple instrument to screen for cognitive impairment in the general population.

Comparison of cognitive dysfunction between schizophrenia and bipolar disorder patients: A meta-analysis of comparative studies

OBJECTIVE

Cognitive dysfunction is common in both schizophrenia and bipolar disorder. This is a meta-analysis of studies that compared cognitive dysfunction between schizophrenia and bipolar disorder.

METHODS

Both international and Chinese databases were systematically searched. Studies that compared cognitive function between schizophrenia and bipolar disorder with the MATRICS Consensus Cognitive Battery (MCCB) were analyzed using the random-effects model.

RESULTS

Twelve studies with 9,518 participants (4,411 schizophrenia and 5,107 bipolar patients) were included in the analyses. Schizophrenia patients performed significantly worse than bipolar patients on the MCCB total scores with a large effect size (SMD=-0.80, 95%CI: -1.21 to -0.39), as well as on all the 7 subscale scores; attention (SMD=-2.56, 95%CI: -3.55 to -1.57) and social cognition (SMD=-0.86, 95%CI: -1.13 to -0.58) with large effect sizes; and speed of processing (SMD=-0.75, 95%CI: -1.00 to -0.49), working memory (SMD=-0.68, 95%CI: -0.91 to -0.45), verbal learning (SMD=-0.78, 95%CI: -0.95 to -0.61), visual learning (SMD=-0.65, 95%CI: -0.83 to -0.48), and reasoning and problem solving (SMD=-0.61, 95%CI: -0.93 to -0.29) with medium effect sizes.

CONCLUSION

Compared to bipolar patients, patients with schizophrenia had more severe cognitive dysfunction in this meta-analysis, particularly in attention and social cognition. Timely assessment and treatment of cognitive dysfunction should be part of standard management protocols in both schizophrenia and bipolar disorder.

Stress-induced impairment in fear discrimination is causally related to increased kynurenic acid formation in the prefrontal cortex

RATIONALE

Stress is related to cognitive impairments which are observed in most major brain diseases. Prior studies showed that the brain concentration of the tryptophan metabolite kynurenic acid (KYNA) is modulated by stress, and that changes in cerebral KYNA levels impact cognition. However, the link between these phenomena has not been tested directly so far.

OBJECTIVES

To investigate a possible causal relationship between acute stress, KYNA, and fear discrimination.

METHODS

Adult rats were exposed to one of three acute stressors-predator odor, restraint, or inescapable foot shocks (ISS)-and KYNA in the prefrontal cortex was measured using microdialysis. Corticosterone was analyzed in a subset of rats. Another cohort underwent a fear discrimination procedure immediately after experiencing stress. Different auditory conditioned stimuli (CSs) were either paired with foot shock (CS+) or were non-reinforced (CS-). One week later, fear was assessed by re-exposing rats to each CS. Finally, to test whether stress-induced changes in KYNA causally impacted fear discrimination, a group of rats that received ISS were pre-treated with the selective KYNA synthesis inhibitor PF-04859989.

RESULTS

ISS caused the greatest increase in circulating corticosterone levels and raised extracellular KYNA levels by ~ 85%. The two other stressors affected KYNA much less (< 25% increase). Moreover, only rats that received ISS were unable to discriminate between CS+ and CS-. PF-04859989 abolished the stress-induced KYNA increase and also prevented the impairment in fear discrimination in animals that experienced ISS.

CONCLUSIONS

These findings demonstrate a causal connection between stress-induced KYNA increases and cognitive deficits. Pharmacological manipulation of KYNA synthesis therefore offers a novel approach to modulate cognitive processes in stress-related disorders.

Using Two-Step Cluster Analysis and Latent Class Cluster Analysis to Classify the Cognitive Heterogeneity of Cross-Diagnostic Psychiatric Inpatients

The heterogeneity of cognitive profiles among psychiatric patients has been reported to carry significant clinical information. However, how to best characterize such cognitive heterogeneity is still a matter of debate. Despite being well suited for clinical data, cluster analysis techniques, like the Two-Step and the Latent Class, received little to no attention in the literature. The present study aimed to test the validity of the cluster solutions obtained with Two-Step and Latent Class cluster analysis on the cognitive profile of a cross-diagnostic sample of 387 psychiatric inpatients. Two-Step and Latent Class cluster analysis produced similar and reliable solutions. The overall results reported that it is possible to group all psychiatric inpatients into Low and High Cognitive Profiles, with a higher degree of cognitive heterogeneity in schizophrenia and bipolar disorder patients than in depressive disorders and personality disorder patients.

Prevalence, clinical correlates of suicide attempt and its relationship with empathy in patients with schizophrenia

OBJECTIVES

Previous studies have shown that cognitive impairment plays a key role in suicide, an important factor leading to premature death in schizophrenia (SCZ) patients. Empathy has received extensive attention recently; however, the relationship of empathy with suicide in schizophrenia is still unknown. The main aim of this study was to investigate the prevalence of suicide attempts and its association with empathy and other characteristics in Chinese chronic SCZ patients.

METHODS

The suicide attempt data, together with demographic characteristics and clinical variables were collected from 627 chronic inpatients with schizophrenia. We utilized the Positive and Negative Syndrome Scale (PANSS) for the psychopathological symptoms, and the Interpersonal Reactivity Index (IRI) for affective and cognitive empathy in this study.

RESULTS

We found a suicide attempt rate of 11.3% in chronic SCZ patients. Compared to non-attempters, suicide attempters were more likely to be women, had younger age and higher education levels, as well as higher positive symptoms and depressive factor score, but lower negative symptoms of PANSS (all p < .05). Moreover, after controlling the confounding factors, suicide attempters scored higher in Personal Distress subscale of IRI (F_{1, 455} = 5.446, p = .020) than non-attempters.

CONCLUSIONS

The prevalence of suicide attempt is high in chronic SCZ patients. Its risk factors include some demographic and clinical variables. Moreover, suicide attempters experienced stronger personal distress, suggesting that stronger empathy may be a risk factor of suicide.

A Pattern of Cognitive Deficits Stratified for Genetic and Environmental Risk Reliably Classifies Patients With Schizophrenia From Healthy Control Subjects

BACKGROUND

Schizophrenia risk is associated with both genetic and environmental risk factors. Furthermore, cognitive abnormalities are established core characteristics of schizophrenia. We aim to assess whether a classification approach encompassing risk factors, cognition, and their associations can discriminate patients with schizophrenia (SCZs) from healthy control subjects (HCs). We hypothesized that cognition would demonstrate greater HC-SCZ classification accuracy and that combined gene-environment stratification would improve the discrimination performance of cognition.

METHODS

Genome-wide association study-based genetic, environmental, and neurocognitive classifiers were trained to separate 337 HCs from 103 SCZs using support vector classification and repeated nested cross-validation. We validated classifiers on independent datasets using within-diagnostic (SCZ) and cross-diagnostic (clinically isolated syndrome for multiple sclerosis, another condition with cognitive abnormalities) approaches. Then, we tested whether gene-environment multivariate stratification modulated the discrimination performance of the cognitive classifier in iterative subsamples.

RESULTS

The cognitive classifier discriminated SCZs from HCs with a balanced accuracy (BAC) of 88.7%, followed by environmental (BAC = 65.1%) and genetic (BAC = 55.5%) classifiers. Similar classification performance was measured in the within-diagnosis validation sample (HC-SCZ BACs, cognition = 70.5%; environment = 65.8%; genetics = 49.9%). The cognitive classifier was relatively specific to schizophrenia (HC-clinically isolated syndrome for multiple sclerosis BAC = 56.7%). Combined gene-environment stratification allowed cognitive features to classify HCs from SCZs with 89.4% BAC.

CONCLUSIONS

Consistent with cognitive deficits being core features of the phenotype of SCZs, our results suggest that cognitive features alone bear the greatest amount of information for classification of SCZs. Consistent with genes and environment being risk factors, gene-environment stratification modulates HC-SCZ classification performance of cognition, perhaps providing another target for refining early identification and intervention strategies.

Screening for cognitive impairment in non-affective psychoses: A comparison between the SCIP and the MoCA

BACKGROUND

Neuropsychological performance has a strong impact on real-life functioning and clinical outcomes in psychosis. However, conducting lengthy cognitive assessments may not be feasible in routine clinical practice. Brief, reliable and cost-effective tools are highly needed, but few studies are available to guide clinician choice.

METHODS

The purpose of this study was to compare the performance of two widely used, short instruments: the Screen for Cognitive Impairment in Psychiatry (SCIP) and the Montreal Cognitive Assessment (MoCA). These instruments were validated in a sample of patients with psychotic disorders and healthy controls, using the Repeatable Battery for the Assessment of Neuropsychological Status (RBANS) and other instruments to assess executive functions, as comparators.

RESULTS

Patients fared worse than controls across almost all cognitive domains, with effect sizes ranging from 0 (MoCA naming) to 2.08 (SCIP total). Receiver Operator Curve analysis of patient and control performance suggested a better convergent validity for the SCIP (total score AUC: 0.85; 95%CI: 0.79-0.90; Se: 76%, Sp: 83%, PPV: 85%, NPV: 73%) than the MoCA (AUC: 0.78; 95%CI: 0.72-0.85; Se: 69%, Sp: 76%, PPV: 78.7%, NPV 66%).

CONCLUSIONS

The Screen for Cognitive Impairment in Psychiatry seems to be a more sensitive and specific screening tool than the MoCA to identify cognitive impairment among patients with psychotic disorders.