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BackgroundCognitive impairment is a clinically important feature of schizophrenia. Polygenic risk score (PRS) methods have demonstrated genetic overlap between schizophrenia, bipolar disorder (BD), major depressive disorder (MDD), educational attainment (EA), and IQ, but very few studies have examined associations between these PRS and cognitive phenotypes within schizophrenia cases.MethodsWe combined genetic and cognitive data in 3034 schizophrenia cases from 11 samples using the general intelligence factor g as the primary measure of cognition. We used linear regression to examine the association between cognition and PRS for EA, IQ, schizophrenia, BD, and MDD. The results were then meta-analyzed across all samples. A genome-wide association studies (GWAS) of cognition was conducted in schizophrenia cases.ResultsPRS for both population IQ (P = 4.39 × 10-28) and EA (P = 1.27 × 10-26) were positively correlated with cognition in those with schizophrenia. In contrast, there was no association between cognition in schizophrenia cases and PRS for schizophrenia (P = .39), BD (P = .51), or MDD (P = .49). No individual variant approached genome-wide significance in the GWAS.ConclusionsCognition in schizophrenia cases is more strongly associated with PRS that index cognitive traits in the general population than PRS for neuropsychiatric disorders. This suggests the mechanisms of cognitive variation within schizophrenia are at least partly independent from those that predispose to schizophrenia diagnosis itself. Our findings indicate that this cognitive variation arises at least in part due to genetic factors shared with cognitive performance in populations and is not solely due to illness or treatment-related factors, although our findings are consistent with important contributions from these factors.

Introduction: Increasing use of CT examinations has led to concerns of possible negative cognitive effects for children. The objective of this study is to examine if the ionizing radiation dose from a CT head scan at the age of 6–16 years affects academic performance and high school eligibility at the end of compulsory school. Materials and methods: A total of 832 children, 535 boys and 297 girls, from a previous trial where CT head scan was randomized on patients presenting with mild traumatic brain injury, were followed. Age at inclusion was 6–16 years (mean of 12.1), age at follow up 15–18 years (mean of 16.0), and time between injury and follow up one week up to 10 years (mean of 3.9). Participants' radiation exposure status was linked with the total grade score, grades in mathematics and the Swedish language, eligibility for high school at the end of compulsory school, previously measured GOSE-score, and their mothers' education level. The Chi-Square Test, Student's t-Test and factorial logistics were used to analyze data. Results: Although estimates of school grades and high school eligibility were generally higher for the unexposed, the results showed no statistically significant differences between the exposed and unexposed participants in any of the aforementioned variables. Conclusions: Any effect on high school eligibility and school grades from a CT head scan at the age of 6–16 years is too small to be detected in a study of more than 800 patients, half of whom were randomly assigned to CT head scan exposure. [ABSTRACT FROM AUTHOR]

Abstract Background Relationships between cognitive deficits and brain morphological changes observed in schizophrenia are alternately explained by less gray matter in the brain cerebral cortex, by alterations in neural circuitry involving the basal ganglia, and by alteration in cerebellar structures and related neural circuitry. This work explored a model encompassing all of these possibilities to identify the strongest morphological relationships to cognitive skill in schizophrenia. Methods Seventy-one patients with schizophrenia and sixty-five healthy control subjects were characterized by neuropsychological tests covering six functional domains. Measures of sixteen brain morphological structures were taken using semi-automatic and fully manual tracing of MRI images, with the full set of measures completed on thirty of the patients and twenty controls. Group differences were calculated. A Bayesian decision-theoretic method identified those morphological features, which best explained neuropsychological test scores in the context of a multivariate response linear model with interactions. Results Patients performed significantly worse on all neuropsychological tests except some regarding executive function. The most prominent morphological observations were enlarged ventricles, reduced posterior superior vermis gray matter volumes, and increased putamen gray matter volumes in the patients. The Bayesian method associated putamen volumes with verbal learning, vigilance, and (to a lesser extent) executive function, while caudate volumes were associated with working memory. Vermis regions were associated with vigilance, executive function, and, less strongly, visuo-motor speed. Ventricular volume was strongly associated with visuo-motor speed, vocabulary, and executive function. Those neuropsychological tests, which were strongly associated to ventricular volume, showed only weak association to diagnosis, possibly because ventricular volume was regarded a proxy for diagnosis. Diagnosis was strongly associated with the other neuropsychological tests, implying that the morphological associations for these tasks reflected morphological effects and not merely group volumetric differences. Interaction effects were rarely associated, indicating that volumetric relationships to neuropsychological performance were similar for both patients and controls. Conclusion The association of subcortical and cerebellar structures to verbal learning, vigilance, and working memory supports the importance of neural connectivity to these functions. The finding that a morphological indicator of diagnosis (ventricular volume) provided more explanatory power than diagnosis itself for visuo-motor speed, vocabulary, and executive function suggests that volumetric abnormalities in the disease are more important for cognition than non-morphological features.

Background The question has been raised whether low dose radiation toward the brain in childhood can affect cognitive functions. Purpose To examine if a head computed tomography (CT) examination in childhood affect later cognitive functions. Material and Methods A total of 147 participants (67 girls/women, 80 boys/men) from a previous randomized controlled trial on management strategies after mild head injury (head CT examination or in-hospital observation) were followed up. Participants were aged 6-16 years (mean age = 11.2 ± 2.8) at first inclusion and 11-24 years (mean age = 17.8 ± 2.9) at follow-up. Computerized neuropsychological measures used for the assessment were motor speed and coordination, reaction time, selective attention, visuospatial ability, verbal and non-verbal short-term and long-term memory, and executive function tests from the neurocognitive test battery EuroCog and the Wechsler Memory Scale III. Results were analyzed with Student's t-tests and multivariate analyses adjusting for sex, age at time of injury/exposure, and age at assessment were performed with Factorial ANOVAs. Results The exposed and unexposed groups did not differ in any of the neuropsychological measures and results did not change when sex, age at time of injury/exposure, and age at assessment were included in the analyses. Conclusion A head CT examination at the age of 6-16 years does not seem to affect later cognitive functions. [ABSTRACT FROM AUTHOR]

Background. Women with breast cancer (BC) report cognitive impairment. Receiving a BC diagnosis may have a negative psychological impact. We sought to determine whether a diagnosis of BC and subsequent surgical treatment reduced cognitive function. Material and methods. We recruited women, who had a positive radiographic finding, consecutively from the mammography screening program at Stockholm South General Hospital. All subjects completed the Headminder Web-based neuropsychological battery Cognitive Stability Index (CSI) for response speed, processing speed, memory, and attention at enrolment (T1, Baseline). CSI was administered again, after BC was ruled out, or after sector resection or mastectomy, if BC was confirmed by cytology or biopsy (T2, Retest). Results and conclusion. Of the 148 women approached, 146 were enrolled; 69 were healthy and 77 had BC. Comparison between groups at baseline, according to independent t-test, showed significant differences in response speed and processing speed. Cognitive abilities did not decline in either group on any of the measured domains. Our results suggest that a diagnosis of BC and subsequent surgery is not associated with substantial cognitive decline at retest. However, the lack of improvement in attention at retest among BC patients may be suggestive of a decline. [ABSTRACT FROM AUTHOR]

Objective: To examine gender differences in prediction of long-term outcome in first episode psychosis (FEP). Method: Eighty-one male and 72 female FEP patients were compared regarding the sensitivity and specificity of the Predictive Rating Scale (PRS). The contributions of pre-admission clinical and socio-demographic characteristics to a poor 5-year outcome were analysed for males and females separately. Gender differences in the relations between predictors and outcome were examined using the equality of correlation comparing correlation coefficients. Results: The sensitivity of the PRS was significantly better for males than for females. The following items: ‘the highest Global Assessment of Functioning (GAF) the year before first admission ≤70’ and ‘GAF at first admission ≤30’ explained most of the variance of a poor 5-year outcome for males, whereas for females the corresponding items were ‘the highest educational level is compulsory school’, ‘living with parents’ and ‘contact with friends ≤2–3 times/month’. When the PRS was adapted assigning a weight of two to the item ‘the highest educational level is compulsory school’ for females, the sensitivity increased. Conclusion: This study revealed that the predictors for poor outcome differ between male and female patients with FEP. Copyright © 2008 John Wiley & Sons, Ltd. [ABSTRACT FROM AUTHOR]

Abstract: Objective: To investigate cognitive outcome after on and off pump coronary artery bypass grafting. Methods: Seventy patients between 50 and 80 years with stable angina pectoris, ejection fraction >30%, serum creatinine <150μmol/l, and lack of tight main stem stenosis were randomized to on or off pump coronary artery bypass grafting. Standardized neuropsychological tests evaluated attention, verbal and visuo-spatial short-term and working memory, verbal learning, delayed recall, visuo-motor speed, and aspects of executive functions. Levels of anxiety and depression were also investigated. Testing was performed before and at 1 week, 1 and 6 months after surgery. Results: There was no difference in cognitive impairment (defined as a 20% reduction in at least 20% of the tests) between groups. The incidence at 1 week post-operatively was 57% in the on pump group and 58% in the off pump group, after 1 month 30% and 12% and after 6 months 19% and 15%, respectively (p for interaction=0.19). There was no difference between groups in anxiety (p =0.18) or depression (p =0.48). Conclusions: This prospective, randomized study showed no differences in post-operative cognitive function after on pump compared to off pump coronary artery bypass grafting in low risk patients. [Copyright &y& Elsevier]

Background: Relationships between cognitive deficits and brain morphological changes observed in schizophrenia are alternately explained by less gray matter in the brain cerebral cortex, by alterations in neural circuitry involving the basal ganglia, and by alteration in cerebellar structures and related neural circuitry. This work explored a model encompassing all of these possibilities to identify the strongest morphological relationships to cognitive skill in schizophrenia., Methods: Seventy-one patients with schizophrenia and sixty-five healthy control subjects were characterized by neuropsychological tests covering six functional domains. Measures of sixteen brain morphological structures were taken using semi-automatic and fully manual tracing of MRI images, with the full set of measures completed on thirty of the patients and twenty controls. Group differences were calculated. A Bayesian decision-theoretic method identified those morphological features, which best explained neuropsychological test scores in the context of a multivariate response linear model with interactions., Results: Patients performed significantly worse on all neuropsychological tests except some regarding executive function. The most prominent morphological observations were enlarged ventricles, reduced posterior superior vermis gray matter volumes, and increased putamen gray matter volumes in the patients. The Bayesian method associated putamen volumes with verbal learning, vigilance, and (to a lesser extent) executive function, while caudate volumes were associated with working memory. Vermis regions were associated with vigilance, executive function, and, less strongly, visuo-motor speed. Ventricular volume was strongly associated with visuo-motor speed, vocabulary, and executive function. Those neuropsychological tests, which were strongly associated to ventricular volume, showed only weak association to diagnosis, possibly because ventricular volume was regarded a proxy for diagnosis. Diagnosis was strongly associated with the other neuropsychological tests, implying that the morphological associations for these tasks reflected morphological effects and not merely group volumetric differences. Interaction effects were rarely associated, indicating that volumetric relationships to neuropsychological performance were similar for both patients and controls., Conclusion: The association of subcortical and cerebellar structures to verbal learning, vigilance, and working memory supports the importance of neural connectivity to these functions. The finding that a morphological indicator of diagnosis (ventricular volume) provided more explanatory power than diagnosis itself for visuo-motor speed, vocabulary, and executive function suggests that volumetric abnormalities in the disease are more important for cognition than non-morphological features.