Neuropsychological deficits in children associated with increased familial risk for schizophrenia

Effectiveness of enhancing cognitive reserve in children, adolescents and young adults at genetic risk for psychosis: Study protocol for a randomized controlled trial

BACKGROUND

Offspring of patients diagnosed with bipolar disorder and schizophrenia (Off-BDSZ) have a high genetic risk of developing a mental illness. The aim of this project is to develop and investigate the efficacy of an intervention aimed at this population, based on the concept of cognitive reserve.

METHODS

This is a multicenter randomized trial with an experimental test-retest design study with control group. Two groups will be included: a community comparison group (CC) and a Off-BDSZ group. A total of 108 Off-BDSZ and 65 CC aged between 6 and 25 years will be recruited. Off-BDSZ participants will be randomized to receive either Cognitive Reserve EnhAncement ThErapy (CREATE) (n=54), or a supportive approach (n=54). The CC group will be assessed at baseline. The duration of the intervention will be 3 months, with 12 weekly group sessions. The primary outcome will be the improvement in CR measured according to change in the Cognitive Reserve Assessment Scale in Health (CRASH) and Cognitive Reserve scale for Adolescents (CORE-A). All participants will be blindly evaluated using clinical, cognitive and neuroimaging measures at baseline, at three months (after the psychological intervention), and at twelve-month follow-up after treatment completion.

DISCUSSION

The results will provide insight into whether the CREATE-Offspring version may enhance cognitive reserve (CR) in child, adolescent and young adult Off-BDSZ as well as advance knowledge about changes in clinical manifestations, neuropsychological performance and brain structure and function associated with improving CR. This novel and cost-effective intervention represents an advance in the framework of preventive interventions in mental health.

TRIAL REGISTRATION

Clinicaltrials.gov, NCT03722082. Registered on 26 October 2018.

Social cognition in youth with a first-degree relative with schizophrenia: A systematic scoping review

Social-cognitive deficits are present in individuals at familial high-risk (FHR) for schizophrenia and may play a role in the onset of the illness. No literature review has examined the social-cognitive profiles of youth at FHR who are within the peak window of risk for developing schizophrenia, which could provide insight on the endophenotypic role of social cognition. This systematic scoping review (1) summarizes the evidence on social-cognitive deficits in youth at FHR, (2) explores brain correlates, and (3) describes social-cognitive deficits and prodromal symptom associations. We searched PsycInfo and PubMed for studies investigating social cognition in FHR youth aged 35 or younger and included 19 studies (FHR=639; controls=689). Studies report that youth at FHR have difficulty recognizing negative emotions, particularly fear. Youth at FHR also have difficulty performing complex theory of mind tasks. Abnormality in corticolimbic and temporoparietal regions are observed in youth at FHR during social-cognitive tasks, but results are inconsistent. Finally, there is evidence for negative associations between prodromal symptoms and performance on emotion regulation and theory of mind tasks, but the research is scarce. This review highlights the need for studies on youth at FHR using longitudinal designs and extensive social-cognitive, brain imaging and clinical measures.

An ERP study on proactive and reactive response inhibition in individuals with schizotypy

Schizotypy, a subclinical group at risk for schizophrenia, has been found to show impairments in response inhibition. However, it remains unclear whether this impairment is accompanied by outright stopping (reactive inhibition) or preparation for stopping (proactive inhibition). We recruited 20 schizotypy and 24 non-schizotypy individuals to perform a modified stop-signal task with electroencephalographic (EEG) data recorded. This task consists of three conditions based on the probability of stop signal: 0% (no stop trials, only go trials), 17% (17% stop trials), and 33% (33% stop trials), the conditions were indicated by the colour of go stimuli. For proactive inhibition (go trials), individuals with schizotypy exhibited significantly lesser increase in go response time (RT) as the stop signal probability increasing compared to non-schizotypy individuals. Individuals with schizotypy also exhibited significantly increased N1 amplitude on all levels of stop signal probability and increased P3 amplitude in the 17% stop condition compared with non-schizotypy individuals. For reactive inhibition (stop trials), individuals with schizotypy exhibited significantly longer stop signal reaction time (SSRT) in both 17% and 33% stop conditions and smaller N2 amplitude on stop trials in the 17% stop condition than non-schizotypy individuals. These findings suggest that individuals with schizotypy were impaired in both proactive and reactive response inhibition at behavioural and neural levels.

Neuropsychological, clinical and environmental predictors of severe mental disorders in offspring of patients with schizophrenia

Offspring of individuals with schizophrenia (SZCOff) are at an increased risk for this disorder. Neuropsychological decline is a core feature of the disorder and researchers have reported increasing impairments in cognition during the prodromal phase in high-risk adolescents. Additionally, factors like the presence of prodromal symptoms or specific behavioral patterns could predict, together with neurocognitive functioning, the risk of conversion to severe mental disorders in SCZOff. This study aims to compare the neuropsychological functioning of a sample of 41 SCZOff children and adolescents and 105 community control offspring (CCOff) and to develop a prediction model to examine whether neuropsychological functioning, clinical and behavioral factors predict subsequent risk of severe mental disorders. We collected demographic, clinical and neuropsychological data. We found significant differences between groups in working memory, speed of processing, verbal memory and learning, visual memory and intelligence quotient (IQ). The socioeconomic status, verbal memory, working memory and positive prodromal symptoms predicted a significant proportion of the dependent variable variance. In conclusion, SCZOff showed neurocognitive impairments in several neuropsychological domains compared to CCOff. Neuropsychological functioning, environmental factors and positive prodromal symptoms could predict the risk of onset of severe mental disorders in SCZOff.

Systematic review and meta-analysis of the relationship between genetic risk for schizophrenia and facial emotion recognition

BACKGROUND

Recent research has highlighted that facial emotion recognition deficits are more common in people with schizophrenia, but the reason for this association is not well understood. Comparing facial recognition deficits in unaffected individuals at higher genetic risk for schizophrenia with individuals at lower genetic risk could increase our understanding of this relationship.

METHODS

We systematically reviewed studies reporting on the relationship between genetic risk of schizophrenia and facial emotion recognition deficits. Meta-analyses were performed where sufficient data were available, otherwise we conducted narrative summaries. Meta-analyses were performed both for generalised and specific facial emotion recognition deficits.

RESULTS

34 studies were included in this review with 23 included in meta-analyses. Meta-analysis indicated strong evidence of a deficit in facial emotion recognition in first-degree relatives of people with schizophrenia compared with controls (SMD 0.38 95% CI 0.26 to 0.51, p ≤ 0.001). Further meta-analyses demonstrated strong evidence of a deficit in the recognition of negative valence facial expressions (SMD 0.19 CI 0.06 to 0.32, p = 0.004) but no evidence of deficit in the recognition of neutral or positive valance.

CONCLUSIONS

There is strong evidence of facial emotion recognition deficits in first-degree relatives of people with schizophrenia. Our findings suggest that such deficits in people with schizophrenia arise prior to the onset of the disorder, though cannot inform whether that association is causal or due to confounding. Emotion recognition deficits, particularly to negative emotions, might be useful predictors of schizophrenia risk.

The interaction between positive schizotypy and high sensitivity C-reactive protein on response inhibition in female individuals

This study aimed to measure the associations between high sensitivity C-reactive protein (hsCRP), childhood maltreatment (CM), schizotypy and response inhibition, and to explore the interactions between hsCRP, CM and schizotypy on response inhibition. Two hundred and fourteen participants completed the Stop-Signal Task (SST), the Schizotypy Personality Questionnaire (SPQ) and the Childhood Trauma Questionnaire-Short Form (CTQ), which measured response inhibition, schizotypy and history of CM respectively. The level of hsCRP was also measured. The high schizotypy group (n = 114) had higher scores on SPQ and CTQ, higher hsCRP levels and longer SST reaction times (SSRTs) than the low schizotypy group (n = 100). In female participants, SSRT had a positive correlation with the SPQ positive factor and the disorganized SPQ factor and a positive correlation with physical neglect. HsCRP was positively correlated with the SPQ negative factor and positive SPQ factor. In male participants, SSRT was negatively correlated with emotional neglect and physical neglect. The majority of correlations between CTQ and SPQ variables were significant in both female and male participants. In female participants, hsCRP significantly predicted SSRT, and hsCRP significantly interacted with positive schizotypy in predicting SSRT.

Prospective memory in non-psychotic first-degree relatives of patients with schizophrenia: a meta-analysis

Prospective memory (PM) could be impaired in the non-psychotic first-degree relatives of patients with schizophrenia. This meta-analysis systematically examined the PM of non-psychotic first-degree relatives of patients with schizophrenia. Both Chinese and English databases were systematically searched for articles from the inception of the databases through November 13, 2018. Case-control studies of PM in non-psychotic first-degree relatives of patients with schizophrenia were included in the analyses. Confidence intervals (CIs) and standardized mean differences (SMDs) were calculated utilizing the random effects model. Four studies (n=268) that compared PM performance between non-psychotic first-degree relatives of patients with schizophrenia (n=136) and healthy controls (n=132) were included. Three studies were rated as "high quality", while the quality of evidence of the three outcomes included in this meta-analysis was moderate. Compared with the healthy controls, the non-psychotic first-degree relatives of patients with schizophrenia showed impairments in overall PM (two studies, n=127; SMD: -0.46; 95% CI=-0.82, -0.11, P=0.01; I=0%), event-based PM (EBPM) (four studies, n=268; SMD: -0.56; 95% CI=-0.80, -0.31, P<0.00001; I=0%), and time-based PM (TBPM) (four studies, n=268; SMD: -0.66; 95% CI=-0.90, -0.41, P<0.00001; I=0%). This meta-analysis demonstrated that the overall PM, EBPM, and TBPM might be impaired in the non-psychotic first-degree relatives of patients with schizophrenia.

Developmental aspects of schizophrenia and related disorders: possible implications for treatment strategies

Schizophrenia and other schizophrenia-spectrum disorders are neurodevelopmental disorders which may share genetic susceptibility factors and represent differential expressions of an underlying vulnerability. Schizophrenia may have its onset in childhood and can be reliably diagnosed. However, developmental factors modulate disease expression in children. Although the prevalence of schizophrenia in childhood is low, children who develop schizophrenia in adult life may show subtle and non-specific developmental abnormalities, consistent with the neurodevelopmental hypothesis. Studies of the schizophrenia prodrome also demonstrate that abnormalities may be apparent years before the onset of positive symptoms. Such evidence raises the possibility of using preventive approaches in the treatment of schizophrenia. Further advances in our knowledge of the aetiopathology of schizophrenia (and the identification of endophenotypes within the group of schizophrenia and related disorders) may further improve our ability to predict disease development, making implementation of preventive interventions more achievable.

A molecular pathway analysis stresses the role of inflammation and oxidative stress towards cognition in schizophrenia

Cognitive processes have a genetic component and are impaired in Schizophrenia (SKZ). The exact nature of such impairment escapes definition. The aim of the present contribution was the identification of the molecular pathways enriched with mutations (SNPs) associated with cognitive performance during antipsychotic treatment. 765 individuals from the CATIE study, males = 559, mean age 40.93 ± 11.03 were included. Working memory and the verbal memory were the evaluated outcomes. A mixed regression model for repeated measures served in R for clinical and molecular pathway analysis. The analysis of quality was conducted under the following criteria: minor allele frequency >0.01, genotype call rate >95%, missing data frequency <5%, Hardy-Weimberg equilibrium threshold >0.0001. The inflation factor was controlled by lambda values. Input for the pathway analysis was SNPs at a p level <0.05 of association genome-wide. Gender, age, education and the duration of the disease were the clinical and socio-demographic variables associated with the cognitive performance. 4268977 SNPs were available after imputation and quality analysis. Pathways related to inflammation and oxidation were the most strongly associated with verbal memory and working memory at a conservative adjusted p value < 0.01. We report that inflammation and in particular the pathway associated with arachidonic acid was enriched in mutations associated with poorer performance at the verbal memory and working memory tasks in SKZ patients.

Neuropsychological characteristics of child and adolescent offspring of patients with schizophrenia or bipolar disorder

BACKGROUND

Schizophrenia (SZ) and bipolar disorder (BD) are considered neurobiological disorders which share some clinical, cognitive and neuroimaging characteristics. Studying child and adolescent offspring of patients diagnosed with bipolar disorder (BDoff) or schizophrenia (SZoff) is regarded as a reliable method for investigating early alterations and vulnerability factors for these disorders. This study compares the neuropsychological characteristics of SZoff, BDoff and a community control offspring group (CC) with the aim of examining shared and differential cognitive characteristics among groups.

METHODS

41 SZoff, 90 BDoff and 107 CC were recruited. They were all assessed with a complete neuropsychological battery which included intelligence quotient, working memory (WM), processing speed, verbal memory and learning, visual memory, executive functions and sustained attention.

RESULTS

SZoff and BDoff showed worse performance in some cognitive areas compared with CC. Some of these difficulties (visual memory) were common to both offspring groups, whereas others, such as verbal learning and WM in SZoff or PSI in BDoff, were group-specific.

CONCLUSIONS

The cognitive difficulties in visual memory shown by both the SZoff and BDoff groups might point to a common endophenotype in the two disorders. Difficulties in other cognitive functions would be specific depending on the family diagnosis.

Endophenotypes in Schizophrenia for the Perinatal Period: Criteria for Validation

Endophenotypes are disease-associated phenotypes that are thought to reflect the neurobiological or other mechanisms that underlie the more overt symptoms of a psychiatric illness. Endophenotypes have been critical in understanding the genetics, neurobiology, and treatment of schizophrenia. Because psychiatric illnesses have multiple causes, including both genetic and nongenetic risk factors, an endophenotype linked to one of the mechanisms may be expressed more frequently than the disease itself. However, in schizophrenia research, endophenotypes have almost exclusively been studied in older adolescents or adults who have entered or passed through the age of risk for the disorder. Yet, schizophrenia is a neurodevelopmental disorder where prenatal development starts a cascade of brain changes across the lifespan. Endophenotypes have only minimally been utilized to explore the perinatal development of vulnerability. One major impediment to the development of perinatally-useful endophenotypes has been the established validity criteria. For example, the criterion that the endophenotype be more frequently present in those with disease than those without is difficult to demonstrate when there can be a decades-long period between endophenotype measurement and the age of greatest risk for onset of the disorder. This article proposes changes to the endophenotype validity criteria appropriate to perinatal research and reviews how application of these modified criteria helped identify a perinatally-usable phenotype of risk for schizophrenia, P50 sensory gating, which was then used to propose a novel perinatal primary prevention intervention.

Prospective memory performance in non-psychotic first-degree relatives of patients with schizophrenia: a controlled study

Objective

We aimed at investigating prospective memory and its socio-demographic and neurocognitive correlates in non-psychotic, first-degree relatives (FDRs) of patients with schizophrenia compared to patients with first episode schizophrenia (FES), and healthy controls (HCs).

Methods

Forty-seven FES patients, 50 non-psychotic FDRs (23 offspring and 27 siblings) of patients with chronic schizophrenia (unrelated to the FES group) and 51 HCs were studied. The Chinese version of the Cambridge Prospective Memory Test (C-CAMPROMPT) was used to measure time-based prospective memory (TBPM) and event-based prospective memory (EBPM) performance. Other cognitive functions (involving respective memory and executive functions) were evaluated with standardized tests.

Results

After controlling for basic demographic characteristics including age, gender and educational level, there was a significant difference between FDRs, FES and HCs with respect to both TBPM (F_(2,142) = 10.4, p<0.001) and EBPM (F_(2,142) = 10.8, p<0.001). Multiple linear regression analyses revealed that lower scores of the Hopkins Verbal Learning Test-Revised (HVLT-R) and the STROOP Word-Color Test (SWCT) contributed to TBPM impairment, while lower educational level and higher scores of the Color Trails Test-2 (CTT-2) contributed to EBPM deficit in FDRs.

Conclusions

FDRs share similar but attenuated prospective memory impairments with schizophrenia patients, suggesting that prospective memory deficits may represent an endophenotype of schizophrenia.

Ecological assessment of executive functions in adolescents genetically at high risk for schizophrenia

OBJECTIVE

This study sought to examine specific executive deficits in the real-life environment among adolescents genetically at high risk for schizophrenia and understand the role of the genetic risk, victimization and family functioning, and their interaction on the deficits.

METHODS

The study included 96 non-affected adolescent offspring and siblings of patients with schizophrenia in the high-risk group (HR) and 193 healthy adolescents in the healthy control group (HC), all aged between 9 and 20 years. All participants completed assessments of executive functions (EFs), victimization, and family functioning.

RESULTS

The multivariate analysis revealed that the HR group reported more difficulties on the Shift, Plan/Organize, and Task Completion scale than the HC group. Significant main effects were also detected for victimization level on all domains of EFs and for adaptability level on Inhibit, Working Memory, Plan, and Task Completion scales. Besides, the group×victimization level interactions were significant for Working Memory and Task Completion scales. Hierarchical regression analysis revealed that the genetic risk and victimization were predictors of executive deficits.

CONCLUSIONS

The HR group showed impaired EFs in the everyday environment. And, the genetic risk for schizophrenia and victimization may be related to executive dysfunction. Our results may provide clues about explaining the mechanisms of executive impairments in the HR group and help to identify new targets for early interventions.

The 22q11.2 deletion syndrome as a window into complex neuropsychiatric disorders over the lifespan

Evidence is rapidly accumulating that rare, recurrent copy number variants represent large effect risk factors for neuropsychiatric disorders. 22q11.2 deletion syndrome (22q11DS) (velocardiofacial syndrome or DiGeorge syndrome) is the most common known contiguous gene deletion syndrome and is associated with diverse neuropsychiatric disorders across the life span. One of the most intriguing aspects of the syndrome is the variability in clinical and cognitive presentation: children with 22q11DS have high prevalence of autism spectrum, attention deficit, and anxiety disorders, as well as psychotic-like features, and up to 30% of adolescents and adults develop schizophrenia-like psychosis. Recently, cases of early-onset Parkinson's disease in adults have been reported, collectively suggesting a role for disrupted dopaminergic neurotransmission in the observed neuropsychiatric phenotypes. There is also some evidence that 22q11DS-associated autism spectrum disorder and schizophrenia represent two unrelated phenotypic manifestations, consistent with a neuropsychiatric pleiotropy model. This genetic lesion thus provides a unique model for the discovery of specific genomic risk and (potentially) protective factors for neuropsychiatric disease. Here, we provide an overview of neuropsychiatric findings to date, which highlight the value of this syndrome in mapping the developmental trajectory of dimensional phenotypes that traverse multiple diagnostic categories. Potential sources of genetic variability that may contribute to the disorder's heterogeneous presentation are reviewed. Because of its known genetic etiology, animal models can readily be developed that recapitulate specific aspects of the syndrome. Future research directions involve translational models and potential for drug screenable targets in the context of this human model system.

Converging levels of analysis on a genomic hotspot for psychosis: insights from 22q11.2 deletion syndrome

Schizophrenia is a devastating neurodevelopmental disorder that, despite extensive research, still poses a considerable challenge to attempts to unravel its heterogeneity, and the complex biochemical mechanisms by which it arises. While the majority of cases are of unknown etiology, accumulating evidence suggests that rare genetic mutations, such as 22q11.2 Deletion Syndrome (22qDS), can play a significant role in predisposition to the illness. Up to 25% of individuals with 22qDS eventually develop schizophrenia; conversely, this deletion is estimated to account for 1-2% of schizophrenia cases overall. This locus of Chromosome 22q11.2 contains genes that encode for proteins and enzymes involved in regulating neurotransmission, neuronal development, myelination, microRNA processing, and post-translational protein modifications. As a consequence of the deletion, affected individuals exhibit cognitive dysfunction, structural and functional brain abnormalities, and neurodevelopmental anomalies that parallel many of the phenotypic characteristics of schizophrenia. As an illustration of the value of rare, highly penetrant genetic subtypes for elucidating pathological mechanisms of complex neuropsychiatric disorders, we provide here an overview of the cellular, network, and systems-level anomalies found in 22qDS, and review the intriguing evidence for this disorder's association with schizophrenia. This article is part of the Special Issue entitled 'Neurodevelopmental Disorders'.

Neurocognition in youth and young adults under age 30 at familial risk for schizophrenia: a quantitative and qualitative review

INTRODUCTION

Neurocognitive dysfunction is a central feature of schizophrenia and is observed during all phases of the illness. Because schizophrenia is known to run in families, studying neurocognitive function in first-degree, nonpsychotic relatives has been a widely utilised strategy for almost 50 years for understanding presumed "genetic risk". Studying nonpsychotic relatives ("familial high-risk", or FHR) allows for identification of cognitive vulnerability markers independent of confounds associated with psychosis.

METHODS

Prior meta-analyses have elucidated the level and pattern of cognitive deficits in the premorbid, prodromal, and postonset periods of psychosis, and in relatives regardless of age. However, no prior quantitative analyses have specifically focused on studies of young first-degree relatives of individuals with schizophrenia who have not passed through the peak age illness risk (<age 30). The English language literature of neuropsychological studies of first-degree relatives for schizophrenia was identified up to 15 May 2011.

RESULTS

From 33 studies, 28 studies met our criteria for quantitative review, utilising >70 individual tests and 250 variables.

CONCLUSIONS

In general, young FHR individuals demonstrated deficits with a moderate level of severity compared with healthy controls. The largest average effect sizes (ESs), based on tests given in at least three independent studies, were on estimates of Full Scale IQ (d= -0.777), followed by Vocabulary (d= -0.749) and single word reading tests (d= -0.698) (often used as estimates of IQ). Measures of declarative memory, sustained attention, working memory and others had more modest ESs. Deficits were milder than in established schizophrenia, but often as severe as in clinical high-risk or putatively prodromal participants and in older relatives examined in prior meta-analyses. Additionally, while assessed from a more limited literature, youth at FHR for schizophrenia tended to show worse neurocognitive functioning than those at FHR for affective psychosis. This suggests that genetic risk for schizophrenia as reflected in a positive FHR carries an especially heavy impact on cognitive ability.

Comparison between young siblings and offspring of subjects with schizophrenia: clinical and neuropsychological characteristics

INTRODUCTION

High rates of psychopathology and worse performance in cognitive areas have been described in high risk (HR) first degree relatives of subjects with schizophrenia. The present study aimed to examine clinical and neuropsychological characteristics in two different groups of first degree relatives of patients with schizophrenia - one of siblings (HRs), and one of offspring (HRo) - and compare them with healthy controls (HC).

METHODS

Participants were 30 HRo, 26 HRs and 33 HC, all aged between 7 and 16 years. Clinical and neuropsychological assessments were completed by all participants.

RESULTS

No significant differences were observed between HR groups in DSM-IV diagnoses. The most prevalent diagnosis in both HR samples was attention deficit/hyperactivity disorder (ADHD) followed by oppositional defiant disorder and generalized anxiety disorder. Both HR groups obtained worse scores than HC on prodromal symptoms, premorbid adjustment and behavioral problem scales. In cognitive areas, HRo performed worse than HC on most WISC-IV index scores, logical memory, visual memory and perceptual organization, whereas HRs only performed worse in WISC-IV indexes, logical memory and perceptual organization. Most of these differences remained stable after controlling for ADHD. The comparison between HRo and HRs showed significant differences in prodromal symptoms and working memory after controlling for ADHD.

CONCLUSION

Similar abnormalities in HRo and HRs were found in relation to clinical and neuropsychological variables. Subtle differences were found between HR groups with HRo showing difficulties in more clinical and neuropsychological areas than HRs and HC. This suggests that, the specific kind of family relationship should to be taken into account in future HR research.

Research review: Cholinergic mechanisms, early brain development, and risk for schizophrenia

The onset of diagnostic symptomology for neuropsychiatric diseases is often the end result of a decades-long process of aberrant brain development. Identification of novel treatment strategies aimed at normalizing early brain development and preventing mental illness should be a major therapeutic goal. However, there are few models for how this goal might be achieved. This review uses the development of a psychophysiological correlate of attentional deficits in schizophrenia to propose a developmental model with translational primary prevention implications. Review of genetic and neurobiological studies suggests that an early interaction between alpha7 nicotinic receptor density and choline availability may contribute to the development of schizophrenia-associated attentional deficits. Therapeutic implications, including perinatal dietary choline supplementation, are discussed.

Cognitive profiles of healthy siblings of schizophrenia patients: application of the cognitive domains of the MATRICS consensus battery

Even though a large body of data suggests the presence of various types of cognitive deficits in the unaffected relatives of schizophrenia patients, more study is needed to clarify the comparative sensitivities of specific cognitive measures for relative-control differences. In this study, the authors compared the cognitive profiles of unaffected siblings of schizophrenia patients and those of patients and normal controls, and attempted to identify cognitive markers that might be associated with genetic liability to schizophrenia. Eighty-eight clinically stable schizophrenia patients, 44 healthy patient siblings, and 100 normal controls were evaluated using comprehensive neuropsychological tests. The domain structure of the MATRICS consensus cognitive battery was adopted, and both domain scores and individual test scores were used in the analysis. Performances of the sibling group were intermediate between those of patients and controls on most measures. A significant difference between the sibling and control groups was observed only in the Category Fluency Test. This cognitive deficit might be caused by familial predisposition to schizophrenia and could be a candidate of endophenotype for schizophrenia.

Relationship between clinical and neuropsychological characteristics in child and adolescent first degree relatives of subjects with schizophrenia

INTRODUCTION

Studies have shown higher rates of psychopathology and cognitive difficulties among relatives of schizophrenia patients than among the general population. This study aimed to analyze the relationship between clinical and neuropsychological characteristics in children and adolescents at high genetic risk for schizophrenia.

METHODS

Participants were 26 children and adolescent first-degree relatives of subjects diagnosed with schizophrenia (high-risk [HR] group) and 20 controls whose parents and siblings did not meet DSM-IV criteria for any psychotic disorder. These two groups were matched by age, sex and socio-economic status and clinical and neuropsychological assessments were completed by all participants.

RESULTS

Among HR children 42.3% were diagnosed with one or more DSM-IV axis I psychiatric disorders. The most common diagnoses were attention deficit/hyperactivity disorder (ADHD) (34.6%) and generalized anxiety disorder (3.8%) There were significant differences between HR children and controls with respect to prodromal symptoms, behavioral problems and premorbid adjustment, as well as on the majority of intelligence subscales, working memory and logical memory. When differences between HR with ADD (HR-ADD), HR without ADD (HR-NADD) and controls were analyzed, significantly higher scores on clinical scales of prodromal symptoms, behavioral problems and premorbid adjustment were found in HR-ADD than in HR-NADD or controls. There were no significant differences in cognitive domains between HR-ADD and HR-NADD, but there were between HR-ADD and controls and between HR-NADD and controls on the Verbal Comprehension Index, Perceptual Reasoning Index, Working Memory Index and GAI.

CONCLUSIONS

Compared to controls, HR children showed more clinical symptoms and cognitive abnormalities. HR children with ADD had worse clinical symptoms than did HR without ADD, although there were no differences in terms of cognitive abnormalities. Both HR groups seem to have similar deficits in neuropsychological performance.

Cognitive performance and cigarette smoking in first-episode psychosis

The purpose of this study is to describe possible differences in cognitive functioning between smoking and non-smoking patients with first-episode psychosis and to determine whether there is a better cognitive profile associated with smoking. We assessed 61 first-episode psychosis patients with a neuropsychological battery that included computerized measurements of attention, working memory, and executive functioning. Patients were grouped into two categories: non-smokers (0 cigarettes/day; n = 30) and smokers (>/=20 cigarettes/day; n = 31). No significant differences were detected in sociodemographic and clinical data between the two groups. For attention tasks, smokers exhibited shorter reaction times in the sustained attention test than non-smokers (P = 0.039) and needed less time to complete the Stroop interference test (P = 0.013). In the working memory task, smokers exhibited shorter reaction times (P = 0.029) and presented a significantly lower percentage of omission (P = 0.002) and commission errors (P = 0.020) than non-smokers. For executive functioning, no differences were detected between groups in performance on the Wisconsin Card Sorting Test. Results indicate that first-episode psychosis patients who are nicotine users have better cognitive functioning in the areas of attention and working memory than patients who are not nicotine users. This study supports the cognitive approach to the self-medication hypothesis, to explain the high rates of cigarette smoking among psychosis patients. These results may be relevant for developing new strategies involving nicotinic receptors for cognitive enhancement in psychosis.

CNTRICS final task selection: working memory

The third meeting of the Cognitive Neuroscience Treatment Research to Improve Cognition in Schizophrenia (CNTRICS) was focused on selecting promising measures for each of the cognitive constructs selected in the first CNTRICS meeting. In the domain of working memory, the 2 constructs of interest were goal maintenance and interference control. CNTRICS received 3 task nominations for each of these constructs, and the breakout group for working memory evaluated the degree to which each of these tasks met prespecified criteria. For goal maintenance, the breakout group for working memory recommended the AX-Continuous Performance Task/Dot Pattern Expectancy task for translation for use in clinical trial contexts in schizophrenia research. For interference control, the breakout group recommended the recent probes and operation/symmetry span tasks for translation for use in clinical trials. This article describes the ways in which each of these tasks met the criteria used by the breakout group to recommend tasks for further development.

Neurocognitive allied phenotypes for schizophrenia and bipolar disorder

Psychiatric disorders are genetically complex and represent the end product of multiple biological and social factors. Links between genes and disorder-related abnormalities can be effectively captured via assessment of phenotypes that are both associated with genetic effects and potentially contributory to behavioral abnormalities. Identifying intermediate or allied phenotypes as a strategy for clarifying genetic contributions to disorders has been successful in other areas of medicine and is a promising strategy for identifying susceptibility genes in complex psychiatric disorders. There is growing evidence that schizophrenia and bipolar disorder, rather than being wholly distinct disorders, share genetic risk at several loci. Further, there is growing evidence of similarity in the pattern of cognitive and neurobiological deficits in these groups, which may be the result of the effects of these common genetic factors. This review was undertaken to identify patterns of performance on neurocognitive and affective tasks across probands with schizophrenia and bipolar disorder as well as unaffected family members, which warrant further investigation as potential intermediate trait markers. Available evidence indicates that measures of attention regulation, working memory, episodic memory, and emotion processing offer potential for identifying shared and illness-specific allied neurocognitive phenotypes for schizophrenia and bipolar disorder. However, very few studies have evaluated neurocognitive dimensions in bipolar probands or their unaffected relatives, and much work in this area is needed.

The stability of inhibitory and working memory deficits in children and adolescents who are children of parents with schizophrenia

Cognitive deficits are a central feature of schizophrenia and occur in first-degree relatives of schizophrenic probands, even in the absence of psychotic symptoms. A number of cognitive domains have been implicated including measures of response inhibition and working memory. While the stability of cognitive deficits has been demonstrated in individuals with schizophrenia, stability of deficits has not been explored in first-degree relatives. This report focuses on 25 children (ages 6-15 years), all with at least one schizophrenic parent. The children were assessed twice, utilizing inhibitory and working memory tasks, with a mean 2.6 years between visits. Stop reaction time (a measure of motor inhibition) and performance on a counting span task (a measure of verbal working memory) were borderline to mildly impaired (compared with a typically developing comparison group) at both visits with similar effect sizes (stopping task time 1, effect size = 0.46, time 2 effect size = 0.50; counting span time 1 effect size = 0.53, time 2 effect size = 0.42). For these 2 tasks, individual age-adjusted scores also correlated across both time points (r = 0.41-0.76) suggesting that individual children maintained deficits across time. As etiologically driven strategies are developed for the cognitive deficits of schizophrenia, expansion of these treatments to relatives who share the cognitive but not the psychotic symptoms may be worth exploring.

Impaired working speed and executive functions as frontal lobe dysfunctions in young first-degree relatives of schizophrenic patients

The aim of the investigation was to detect neuropsychological markers, such as sustained and selective attention and executive functions, which contribute to the vulnerability to schizophrenia especially in young persons. Performance was assessed in 32 siblings and children of schizophrenic patients and 32 matched controls using Wisconsin Card Sorting Test, Colour-Word-Interference-Test, Trail Making Test, and d2-Concentration-Test. The first-degree relatives showed certain impairments on all four tests, in particular, slower times on all time-limited tests. These results suggest the need for more time when completing neuropsychological tasks involving selected and focused attention, as well as cognitive flexibility, as a possible indicator of genetic vulnerability to schizophrenia.

Neuropsychological functioning in adolescents and young adults at genetic risk for schizophrenia and affective psychoses: results from the Harvard and Hillside Adolescent High Risk Studies

Siblings and offspring of persons with schizophrenia carry elevated genetic risk for the illness and manifest attentional and memory impairments. Because less is known about other neuropsychological functions and their specificity in adolescents, we conducted a genetic high-risk (HR) study of schizophrenia (HR-SCZ) and affective psychosis (HR-AFF). Participants (ages 12-25) were from the Harvard Adolescent High-Risk and Hillside Family studies, including 73 HR-SCZ, 18 HR-AFF, and 84 community controls (CCs) recruited in metropolitan Boston and New York. Groups were compared on overall neurocognitive functioning, 6 domains, and 13 test scores, controlling for age, parental education, and correlated data within families. The HR-SCZ group was significantly impaired overall, while the HR-AFF group demonstrated a trend toward overall impairment. HR-SCZ subjects showed significantly lower Verbal Ability (d = .73) and Executive Functioning/Working Memory (d = .47) than CCs. HR-AFF subjects showed reduced Verbal Ability (d = .64) compared to CCs. Excluding 12 CCs with a parental history of depression (without psychosis) led to larger differences between HR and CC groups across domains. Moreover, HR-SCZ and CC group differences in Verbal Memory (d = .39) and Visual-Spatial (d = .34) became statistically significant. There were no significant differences between HR-SCZ and HR-AFF groups. Data support a modest neuropsychological deficit in persons at genetic HR for psychosis, with a broader range of deficits in HR-SCZ. Future work should assess the relationship of neurocognition to adaptive functioning and possible onset of psychosis in HR samples. Ascertainment criteria for controls may markedly influence results and interpretation of group differences.

Psychotic symptoms in children and adolescents with 22q11.2 deletion syndrome: Neuropsychological and behavioral implications

Individuals with 22q11.2 deletion syndrome (22q11DS) are at increased risk for developing schizophrenia: half of affected adolescents report transient psychotic experiences and up to 30% of adults are diagnosed with schizophrenia. Prospective studies have shown that psychotic symptoms in childhood are predictive of later schizophreniform disorders. The current study aimed to define the prevalence and correlates of psychotic symptoms (PS) in young children and adolescents with 22q11DS. Forty-three children and adolescents with 22q11DS (mean age = 10.62+/-11.19) participated in this study. The occurrence of PS and their neuropsychological and behavioral correlates were investigated through semi-structured interviews and standardized measures. Psychotic symptoms were reported in 28% of the total sample and 17% of pre-adolescent children, and associated with decreased verbal IQ scores [F(1) = 4.41, p = 0.042]. Compared to young patients without PS, young patients with PS were perceived by their parents as more anxious-depressed [F(1) = 4.76, p = 0.035] and withdrawn [F(1) = 7.63, p = 0.009], with reduced adaptive socialization skills [F(1) = 6.88, p = 0.012]. Results suggest that psychotic manifestations are present earlier than typically reported in youngsters with 22q11DS and are accompanied by reduced verbal IQ performance and decreased adaptative social skills. The symptomatic, neuropsychological and behavioral characteristics observed in the current study may constitute central markers of increased risk for psychosis in 22q11DS.

Cognitive deficits in the families of patients with schizophrenia

PURPOSE OF REVIEW

Studies of first-degree relatives of patients with schizophrenia over the past 25 years have reported a number of cognitive deficits, primarily in the domains of memory and executive function. Nevertheless, due to a number of methodological issues, such as including different types of relatives and not controlling for possible psychopathology, it is not yet clear that these findings can fully support a conclusion of heritability of cognitive dysfunction associated with a schizophrenia genotype.

RECENT FINDINGS

Several recent meta-analyses have shown that the most consistent deficit shown by relatives is impaired performance on 'maintenance plus' frontal-lobe tasks requiring increased effort and higher central executive processing. Studies of multiplex families (multiple diagnoses in one family) also report that family members tend to have more difficulty on executive function tasks. Another interesting trend is research on subgroups of patients and relatives displaying distinct cognitive syndromes, particularly a subgroup with a generalized cognitive deficit.

SUMMARY

As methodological designs improve, this field of study holds promise not only for understanding the neurobiological mechanisms of schizophrenia and the associated cognitive deficits, but also for possibly describing endophenotypes that may lead to identifying at-risk patients and relatives.

ADHD and schizophrenia phenomenology: visual scanpaths to emotional faces as a potential psychophysiological marker?

Commonalities in the clinical phenomenology and psychopharmacology of ADHD and schizophrenia are reviewed. The potential of psychostimulants to produce psychotic symptoms emphasizes the need for objective psychophysiological distinctions between these disorders. Impaired emotion perception in both disorders is discussed. It is proposed that visual scanpaths to facial expressions of emotion might prove a potentially useful psychophysiological distinction between ADHD and schizophrenia. There is consistent evidence that both facial affect recognition and scanpaths to facial expressions are impaired in schizophrenia, with emerging empirical evidence showing that facial affect recognition is impaired in ADHD also. Brain imaging studies show reduced activity in the medial prefrontal and limbic (amygdala) brain regions required to process emotional faces in schizophrenia, but suggest more localized loss of activity in these regions in ADHD. As amygdala activity in particular has been linked to effective visual scanning of face stimuli, it is postulated that condition-specific breakdowns in these brain regions that subserve emotional behavior might manifest as distinct scanpath aberrations to facial expressions of emotion in schizophrenia and ADHD.

Early biomarkers of psychosis

Biological traits that are predictive of the later development of psychosis have not yet been identified. The complex, multidetermined nature of schizophrenia and other psychoses makes it unlikely that any single biomarker will be both sensitive and specific enough to unambiguously identify individuals who will later become psychotic. However, current genetic research has begun to identify genes associated with schizophrenia, some of which have phenotypes that appear early in life. While these phenotypes have low predictive power for identifying individuals who will become psychotic, they do serve as biomarkers for pathophysiological processes that can become the targets of prevention strategies. Examples are given from work on the role of the alpha(T)nicotinic receptor and its gene CHRNA7 on chromosome 15 in the neurobiology and genetic transmission of schizophrenia.

Saccadic eye movement task identifies cognitive deficits in children with schizophrenia, but not in unaffected child relatives

BACKGROUND

The delayed oculomotor response (DOR) task requires response inhibition followed by movement of gaze towards a known spatial location without a current stimulus. Abnormalities in response inhibition and in the spatial accuracy of the eye movement are found in individuals with schizophrenia and in many of their relatives, supporting the use of these saccadic abnormalities as endophenotypes in genetic studies. It is unknown whether school-age children, either with psychosis or as relatives of a schizophrenic proband, can be included.

METHOD

One hundred eighty-seven children, ages 5.8-16.0 years - 45 children with childhood-onset schizophrenia, 64 children with a first-degree relative with schizophrenia, and 84 typically developing children - completed DOR tasks with 1 and 3 second delays.

RESULTS

Children with childhood-onset schizophrenia demonstrated impaired response inhibition and impaired spatial accuracy compared to both relatives and typicals; however, relatives and typicals did not differ from each other.

CONCLUSIONS

Children with childhood-onset schizophrenia have saccadic abnormalities similar to those found in adults with schizophrenia, supporting the continuity of executive function deficits in childhood-onset with adolescent and adult-onset schizophrenia. However, saccadic tasks are not sensitive to genetic risk in non-psychotic children and 6-15-year-old children should not be included in genetic studies utilizing this endophenotype.

From clinical research to clinical practice: a 4-year review of ziprasidone

Ziprasidone is a second-generation antipsychotic that received Food and Drug Administration approval in February 2001. It has a unique receptor profile that includes high-affinity antagonist activity at dopamine D2 receptors, inverse agonist activity at serotonin (5-HT)2A receptors, agonist activity at 5-HTlA receptors, and a relatively high affinity for the serotonin and norepinephrine transporters. The 5-HTIA affinity, together with the inhibitory effect on mono-amine reuptake, may underlie the hypothesized beneficial effects on comorbid affective and cognitive abnormalities in schizophrenia and schizoaffective disorder. The short-term efficacy of ziprasidone for core positive symptoms of schizophrenia appears to be comparable to other conventional and atypical antipsychotics. The short-term efficacy of ziprasidone in acute mania has been established based on two 3-week, double-blind, placebo-controlled trials.Open-label treatment for up to 52 weeks confirms the sustained efficacy and safety of ziprasidone in bipolar disorder. Maintenance studies in schizophrenia and schizoaffective disorder indicate that long-term ziprasidone therapy is effective in preventing relapse, while maintaining cognitive and psychosocial benefits. The safety database suggests that the overall cardiovascular and cerebrovascular risk associated with ziprasidone is lower than with other atypicals, with notably lower risk of drug-related increases in weight, glucose, or lipids. The data also suggest a modestly increased risk of QTc prolongation that is not dose related or linked to torsades de pointes. Switching to ziprasidone from other atypicals appears to improve both clinical symptoms and metabolic parameters, though more studies are needed to fully characterize these benefits. This monograph summarizes the efficacy, tolerability, and safety of oral ziprasidone in the treatment of schizophrenia, schizoaffective disorder, and bipolar mania.

Gait disturbances in patients with schizophrenia and adaptation to treadmill walking

This study evaluated the gait patterns of schizophrenic patients at free gait and at three fixed velocities on a treadmill. The effects of illness and antipsychotic treatment on gait parameters and on adaptation to treadmill walking were compared. Gait parameters of 14 drug-naive schizophrenic patients, 14 patients treated with conventional antipsychotics, 14 patients treated with olanzapine, as well as 14 matched controls were assessed on a walkway and on a treadmill at three different velocities (very slow, intermediately slow, and comfortable) using an ultrasonic movement analysis system. At free gait, all patients showed a significantly decreased gait velocity, predominantly due to a shorter stride length, when compared to the controls, with the most striking difference observed between the patients treated with conventional neuroleptics and the controls (ANOVA, P < or = 0.001). Cadence (steps per second) did not differ between the investigated groups. When gait was evaluated on the treadmill, differences in stride length and cadence were significant only at the very slow treadmill velocity (ANOVA, P < or = 0.05). In all patient groups, mean stride length was decreased and cadence compensationally increased. Significant differences between the patient groups were no longer detectable. With increasing treadmill velocities, gait parameters of all patient groups normalized. The results show that, like in patients with Parkinson's Disease, impaired gait parameters can also be normalized in schizophrenic patients by external stimulation via treadmill walking.