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146 result(s) for "Kirov, George"
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Schizophrenia-associated genomic copy number variants and subcortical brain volumes in the UK Biobank
Schizophrenia is a highly heritable disorder for which anatomical brain alterations have been repeatedly reported in clinical samples. Unaffected at-risk groups have also been studied in an attempt to identify brain changes that do not reflect reverse causation or treatment effects. However, no robust associations have been observed between neuroanatomical phenotypes and known genetic risk factors for schizophrenia. We tested subcortical brain volume differences between 49 unaffected participants carrying at least one of the 12 copy number variants associated with schizophrenia in UK Biobank and 9063 individuals who did not carry any of the 93 copy number variants reported to be pathogenic. Our results show that CNV carriers have reduced volume in some of the subcortical structures previously shown to be reduced in schizophrenia. Moreover, these associations partially accounted for the association between pathogenic copy number variants and cognitive impairment, which is one of the features of schizophrenia.
Cognitive performance and functional outcomes of carriers of pathogenic copy number variants: analysis of the UK Biobank
Rare copy number variants (CNVs) are associated with risk of neurodevelopmental disorders characterised by varying degrees of cognitive impairment, including schizophrenia, autism spectrum disorder and intellectual disability. However, the effects of many individual CNVs in carriers without neurodevelopmental disorders are not yet fully understood, and little is known about the effects of reciprocal copy number changes of known pathogenic loci.AimsWe aimed to analyse the effect of CNV carrier status on cognitive performance and measures of occupational and social outcomes in unaffected individuals from the UK Biobank. We called CNVs in the full UK Biobank sample and analysed data from 420 247 individuals who passed CNV quality control, reported White British or Irish ancestry and were not diagnosed with neurodevelopmental disorders. We analysed 33 pathogenic CNVs, including their reciprocal deletions/duplications, for association with seven cognitive tests and four general measures of functioning: academic qualifications, occupation, household income and Townsend Deprivation Index. Most CNVs (24 out of 33) were associated with reduced performance on at least one cognitive test or measure of functioning. The changes on the cognitive tests were modest (average reduction of 0.13 s.d.) but varied markedly between CNVs. All 12 schizophrenia-associated CNVs were associated with significant impairments on measures of functioning. CNVs implicated in neurodevelopmental disorders, including schizophrenia, are associated with cognitive deficits, even among unaffected individuals. These deficits may be subtle but CNV carriers have significant disadvantages in educational attainment and ability to earn income in adult life.Declaration of interestNone.
Medical consequences of pathogenic CNVs in adults: analysis of the UK Biobank
BackgroundGenomic CNVs increase the risk for early-onset neurodevelopmental disorders, but their impact on medical outcomes in later life is still poorly understood. The UK Biobank allows us to study the medical consequences of CNVs in middle and old age in half a million well-phenotyped adults.MethodsWe analysed all Biobank participants for the presence of 54 CNVs associated with genomic disorders or clinical phenotypes, including their reciprocal deletions or duplications. After array quality control and exclusion of first-degree relatives, we compared 381 452 participants of white British or Irish origin who carried no CNVs with carriers of each of the 54 CNVs (ranging from 5 to 2843 persons). We used logistic regression analysis to estimate the risk of developing 58 common medical phenotypes (3132 comparisons).Results and conclusionsMany of the CNVs have profound effects on medical health and mortality, even in people who have largely escaped early neurodevelopmental outcomes. Forty-six CNV–phenotype associations were significant at a false discovery rate threshold of 0.1, all in the direction of increased risk. Known medical consequences of CNVs were confirmed, but most identified associations are novel. Deletions at 16p11.2 and 16p12.1 had the largest numbers of significantly associated phenotypes (seven each). Diabetes, hypertension, obesity and renal failure were affected by the highest numbers of CNVs. Our work should inform clinicians in planning and managing the medical care of CNV carriers.
Analysis of copy number variations at 15 schizophrenia-associated loci
A number of copy number variants (CNVs) have been suggested as susceptibility factors for schizophrenia. For some of these the data remain equivocal, and the frequency in individuals with schizophrenia is uncertain. To determine the contribution of CNVs at 15 schizophrenia-associated loci (a) using a large new data-set of patients with schizophrenia (n = 6882) and controls (n = 6316), and (b) combining our results with those from previous studies. We used Illumina microarrays to analyse our data. Analyses were restricted to 520 766 probes common to all arrays used in the different data-sets. We found higher rates in participants with schizophrenia than in controls for 13 of the 15 previously implicated CNVs. Six were nominally significantly associated (P<0.05) in this new data-set: deletions at 1q21.1, NRXN1, 15q11.2 and 22q11.2 and duplications at 16p11.2 and the Angelman/Prader-Willi Syndrome (AS/PWS) region. All eight AS/PWS duplications in patients were of maternal origin. When combined with published data, 11 of the 15 loci showed highly significant evidence for association with schizophrenia (P<4.1×10(-4)). We strengthen the support for the majority of the previously implicated CNVs in schizophrenia. About 2.5% of patients with schizophrenia and 0.9% of controls carry a large, detectable CNV at one of these loci. Routine CNV screening may be clinically appropriate given the high rate of known deleterious mutations in the disorder and the comorbidity associated with these heritable mutations.
Schizophrenia, autism spectrum disorders and developmental disorders share specific disruptive coding mutations
People with schizophrenia are enriched for rare coding variants in genes associated with neurodevelopmental disorders, particularly autism spectrum disorders and intellectual disability. However, it is unclear if the same changes to gene function that increase risk to neurodevelopmental disorders also do so for schizophrenia. Using data from 3444 schizophrenia trios and 37,488 neurodevelopmental disorder trios, we show that within shared risk genes, de novo variants in schizophrenia and neurodevelopmental disorders are generally of the same functional category, and that specific de novo variants observed in neurodevelopmental disorders are enriched in schizophrenia ( P  = 5.0 × 10 −6 ). The latter includes variants known to be pathogenic for syndromic disorders, suggesting that schizophrenia be included as a characteristic of those syndromes. Our findings imply that, in part, neurodevelopmental disorders and schizophrenia have shared molecular aetiology, and therefore likely overlapping pathophysiology, and support the hypothesis that at least some forms of schizophrenia lie on a continuum of neurodevelopmental disorders. Overlapping genes have been implicated in schizophrenia and neurodevelopmental disorders. Here, the authors overlap de novo variants in the two types of disorders and find variants in these genes with the same functional effect and in some cases the same specific variants.
Evaluation of cumulative cognitive deficits from electroconvulsive therapy
Electroconvulsive therapy (ECT) is the most effective acute treatment for severe depression, but widely held concerns about memory problems may limit its use. To find out whether repeated or maintenance courses of ECT cause cumulative cognitive deterioration. Analysis of the results of 10 years of cognitive performance data collection from patients who have received ECT. The 199 patients had a total of 498 assessments, undertaken after a mean of 15.3 ECT sessions (range 0-186). A linear mixed-effect regression model was used, testing whether an increasing number of ECT sessions leads to deterioration in performance. The total number of previous ECT sessions had no effect on cognitive performance. The major factors affecting performance were age, followed by the severity of depression at the time of testing and the number of days since the last ECT session. Repeated courses of ECT do not lead to cumulative cognitive deficits. This message is reassuring for patients, carers and prescribers who are concerned about memory problems and confusion during ECT.
Clinical indicators of treatment-resistant psychosis
Around 30% of individuals with schizophrenia remain symptomatic and significantly impaired despite antipsychotic treatment and are considered to be treatment resistant. Clinicians are currently unable to predict which patients are at higher risk of treatment resistance. To determine whether genetic liability for schizophrenia and/or clinical characteristics measurable at illness onset can prospectively indicate a higher risk of treatment-resistant psychosis (TRP). In 1070 individuals with schizophrenia or related psychotic disorders, schizophrenia polygenic risk scores (PRS) and large copy number variations (CNVs) were assessed for enrichment in TRP. Regression and machine-learning approaches were used to investigate the association of phenotypes related to demographics, family history, premorbid factors and illness onset with TRP. Younger age at onset (odds ratio 0.94, P = 7.79 × 10-13) and poor premorbid social adjustment (odds ratio 1.64, P = 2.41 × 10-4) increased risk of TRP in univariate regression analyses. These factors remained associated in multivariate regression analyses, which also found lower premorbid IQ (odds ratio 0.98, P = 7.76 × 10-3), younger father's age at birth (odds ratio 0.97, P = 0.015) and cannabis use (odds ratio 1.60, P = 0.025) increased the risk of TRP. Machine-learning approaches found age at onset to be the most important predictor and also identified premorbid IQ and poor social adjustment as predictors of TRP, mirroring findings from regression analyses. Genetic liability for schizophrenia was not associated with TRP. People with an earlier age at onset of psychosis and poor premorbid functioning are more likely to be treatment resistant. The genetic architecture of susceptibility to schizophrenia may be distinct from that of treatment outcomes.
Effects of pathogenic CNVs on physical traits in participants of the UK Biobank
Background Copy number variants (CNVs) have been shown to increase risk for physical anomalies, developmental, psychiatric and medical disorders. Some of them have been associated with changes in weight, height, and other physical traits. As most studies have been performed on children and young people, these effects of CNVs in middle-aged and older people are not well established. The UK Biobank recruited half a million adults who provided a variety of physical measurements. We called all CNVs from the Affymetrix microarrays and selected a set of 54 CNVs implicated as pathogenic (including their reciprocal deletions/duplications) and that were found in five or more persons. Linear regression analysis was used to establish their association with 16 physical traits relevant to human health. Results 396,725 participants of white British or Irish descent (excluding first-degree relatives) passed our quality control filters. Out of the 864 CNV/trait associations, 214 were significant at a false discovery rate of 0.1, most of them novel. Many of these traits increase risk for adverse health outcomes: e.g. increases in weight, waist-to-hip ratio, pulse rate and body fat composition. Deletions at 16p11.2, 16p12.1, NRXN1 and duplications at 16p13.11 and 22q11.2 produced the highest numbers of significant associations. Five CNVs produced average changes of over one standard deviation for the 16 traits, compared to controls: deletions at 16p11.2 and 22q11.2, and duplications at 3q29, the Williams-Beuren and Potocki-Lupski regions. CNVs at 1q21.1, 2q13, 16p11.2 and 16p11.2 distal, 16p12.1, 17p12 and 17q12 demonstrated one or more mirror image effects of deletions versus duplications. Conclusions Carriers of many CNVs should be monitored for physical traits that increase morbidity and mortality. Genes within these CNVs can give insights into biological processes and therapeutic interventions.
Ketamine or ECT? What Have We Learned From the KetECT and ELEKT-D Trials?
Abstract 1. Two recent clinical trials, KetECT and ELEKT-D, compared the effectiveness of ketamine and electroconvulsive therapy (ECT) for major depressive disorder. Notably, these trials reported marked differences in ECT's clinical outcomes of, with remission rates of 63% for KetECT and a strikingly lower rate of 22% for ELEKT-D, while the remission rates for ketamine were 46% and 38%, respectively. Considering that the primary objective of both trials was to compare the standard treatment (ECT) with an experimental intervention (ketamine), it is crucial to highlight the pronounced disparities in ECT’s clinical outcomes. This article offers a comprehensive comparison of these trials while also exploring how patient characteristics, treatment protocols, and study designs may contribute to such pronounced outcome discrepancies. These differences highlight the heterogeneous nature of depression and underscore the need for personalized treatments. These studies also provide valuable insights into identifying the most suitable candidates for ketamine and ECT.
What Are the Precipitating Factors of Suicide in South Korea? A Systematic Review
AimsToday the problem of suicide remains one of the topical issues among Asian countries like South Korea. The primary objective of this Systematic Review (SR) was the identification of the risk factors in suicide attempts and completions in South Korea. South Korea has one of the highest reported suicide rates in the world, and there was no prior systematic review on this topic. The main intention was to provide evidence-based results for future research studies and to inform suicide prevention policies.MethodsPubMed, Science Direct, and Medline databases were searched from 1990 to October 2022. Studies focused on the problem of suicide in South Korea were selected with an emphasis on risk factors. Since the rate of suicide rises with age, studies examining 18-year-olds and above were included. Studies examining people of different sociodemographic backgrounds and people diagnosed with psychiatric/psychological disorders and those who attempted suicide, as well as those without a psychiatric/psychological problem, were also included. To assess the overall quality of the included studies, the Critical Appraisal Skills Programme (CASP) checklist was applied for the evaluation of case-control and cohort studies. The National Institutes of Health (NIH) Quality Assessment Tool was implemented for the evaluation of cross-sectional studies. The Jadad Scale was used to assess the risk of bias. PRISMA reporting guidelines were followed.ResultsTen studies met the eligibility criteria to be included in SR: Four cross-sectional, two cross-cultural, and four cohort studies. Risk of bias assessment demonstrated low quality and moderate risk of bias. The quality assessment showed an acceptable level of relevance and quality. Findings suggested factors leading to suicide in South Korea were mental health conditions, financial status, such as unemployment and low income, education level less than high school, and households with poor living conditions. The identified risk factors significantly increased the likelihood of suicide ideation, suicide attempt and suicide completion among people in South Korea. Stigma was identified as a barrier to those with mental health conditions seeking professional help.ConclusionThe identified risk factors are similar across the world; however, the suicide rates are not as high in other Western cultures as they are in South Korea. Future studies could compare Western countries to hierarchical countries to identify if there are any local risk factors that can help guide local prevention policies and educational programs with city officials’ engagement. Moreover, it would be essential to investigate the impact of stigma thoroughly since it is still hard to clarify whether it is a cultural issue or a worldwide issue preventing individuals from getting professional help.