335 research outputs found

    Defensive responses to threat scenarios in Brazilians reproduce the pattern of Hawaiian Americans and non-human mammals

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    A former study with scenarios conducted in Hawaii has suggested that humans share with non-human mammals the same basic defensive strategies - risk assessment, freezing, defensive threat, defensive attack, and flight. The selection of the most adaptive strategy is strongly influenced by features of the threat stimulus - magnitude, escapability, distance, ambiguity, and availability of a hiding place. Aiming at verifying if these strategies would be consistent in a different culture, 12 defensive scenarios were translated into Portuguese and adapted to the Brazilian culture. The sample consisted of male and female undergraduate students divided into two groups: 76 students, who evaluated the five dimensions of each scenario and 248 medical students, who chose the most likely response for each scenario. In agreement with the findings from studies of non-human mammal species, the scenarios were able to elicit different defensive behavioral responses, depending on features of the threat. "Flight" was chosen as the most likely response in scenarios evaluated as an unambiguous and intense threat, but with an available route of escape, whereas "attack" was chosen in an unambiguous, intense and close dangerous situation without an escape route. Less urgent behaviors, such as "check out", were chosen in scenarios evaluated as less intense, more distant and more ambiguous. Moreover, the results from the Brazilian sample were similar to the results obtained in the original study with Hawaiian students. These data suggest that a basic repertoire of defensive strategies is conserved along the mammalian evolution because they share similar functional benefits in maintaining fitness.CNP

    Effect of escitalopram on the processing of emotional faces

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    Serotonin has been implicated in the neurobiology of depressive and anxiety disorders, but little is known about its role in the modulation of basic emotional processing. The aim of this study was to determine the effect of the selective serotonin reuptake inhibitor, escitalopram, on the perception of facial emotional expressions. Twelve healthy male volunteers completed two experimental sessions each, in a randomized, balanced order, double-blind design. A single oral dose of escitalopram (10 mg) or placebo was administered 3 h before the task. Participants were presented to a task composed of six basic emotions (anger, disgust, fear, happiness, sadness, and surprise) that were morphed between neutral and each standard emotion in 10% steps. Escitalopram facilitated the recognition of sadness and inhibited the recognition of happiness in male, but not female faces. No drug effect on subjective measures was detected. These results confirm that serotonin modulates the recognition of emotional faces, and suggest that the gender of the face can have a role in this modulation. Further studies including female volunteers are needed

    The response of social anxiety disorder patients to threat scenarios differs from that of healthy controls

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    The objective of the present study was to evaluate the response of social anxiety disorder (SAD) patients to threat scenarios. First-choice responses to 12 scenarios describing conspecific threatening situations and mean scores of defensive direction and defensive intensity dimensions were compared between 87 SAD patients free of medication and 87 matched healthy controls (HC). A significant gender difference in the first-choice responses was identified for seven scenarios among HCs but only for two scenarios among SAD patients. A significantly higher proportion of SAD patients chose "freezing" in response to "Bush" and "Noise" scenarios, whereas the most frequent response by HCs to these scenarios was "check out". SAD males chose "run away" and "yell" more often than healthy men in response to the scenarios "Park" and "Elevator", respectively. There was a positive correlation between the severity of symptoms and both defensive direction and defensive intensity dimensions. Factorial analysis confirmed the gradient of defensive reactions derived from animal studies. SAD patients chose more urgent defensive responses to threat scenarios, seeming to perceive them as more dangerous than HCs and tending to move away from the source of threat. This is consistent with the hypothesis that the physiopathology of anxiety disorders involves brain structures responsible for defensive behaviors

    Effect of D2R, NMDAR and CB1R genetic variants associated with cannabis use and childhood trauma in first-episode psychosis in a Brazilian population [abstract only]

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    Introduction Gene-environment interactions increase psychosis risk (Gayer-Anderson et al. Soc Psychiatry Psychiatr Epidemiol 2020; 55(5):645-657). However, identifying the genetic variants involved and how they interact with environmental risk factors underlying psychosis remains challenging. Objectives To investigate whether there are gene-environment interactions in the relationships of childhood trauma, lifetime cannabis use, and single nucleotide variants (SNVs) of dopamine D2 receptor (D2R: DRD2), N-methyl-d-aspartate receptor (NMDAR: GRIN1, GRIN2A and GRIN2B) and cannabinoid receptor type 1 (CB1R: CNR1) with psychosis. Methods In a population-based case-control study nested in an incident study (STREAM, Brazil) (Del-Ben et al. Br J of Psychiatry 2019; 215(6):726-729), part of the EU-GEI consortium (Gayer-Anderson et al. Soc Psychiatry Psychiatr Epidemiol 2020; 55(5):645-657), 143 first-episode psychosis patients and 286 community-based controls of both sexes aged between 16 and 64 years were included over a period of 3 years. Twenty-three SNVs of D2R (rs1799978, rs7131056, rs6275), NMDAR (GRIN1: rs4880213, rs11146020; GRIN2A: rs1420040, rs11866328; GRIN2B: rs890, rs2098469, rs7298664), and CB1R genes (CNR1: rs806380, rs806379, rs1049353, rs6454674, rs1535255, rs2023239, rs12720071, rs6928499, rs806374, rs7766029, rs806378, rs10485170, rs9450898), were genotyped from peripheral blood DNA using a custom Illumina HumanCoreExome-24 BeadChip. Environmental adversities were evaluated using the Cannabis Experience Questionnaire (Di Forti et al. The Lancet Psychiatry 2009; 6(5):427–436) and the Childhood Trauma Questionnaire (Grassi-Oliveira et al. Rev Saude Publica 2006; 40(2):249-55). Associations between SNVs and environmental risk factors were performed using the nonparametric multifactor dimensionality reduction software (version 3.0.2). Results Single locus analysis showed no association among the 23 SNVs with psychosis; however, gene-environment analysis was significant for the polymorphic loci rs12720071 and rs7766029 in CNR1. The best association models were the two-factor representing by the combination of CNR1 rs12720071 with lifetime cannabis use (p<0.001), and CNR1 rs12720071 with childhood trauma (p<0.05), both suggesting an increased risk of psychosis. Additionally, when considering the interaction of both environmental factors in the same model, we found CNR1 rs7766029 to be associated with psychosis (p<0.001). Conclusions Our study supports the hypothesis of gene-environment interactions for psychosis involving the T allele carriers of CNR1 SNVs (rs12720071 and rs7766029), childhood trauma and lifetime cannabis use in psychosis

    Gene and environmental risk factors: interplay between CNR1 genetic variants cannabis use, childhood trauma and psychosis [abstract only]

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    Background: Cannabis use and childhood trauma have been proposed as environmental risk factors for psychosis and its known that gene-environment (G×E) interactions increase the risk of psychosis [1]. In particular, a recent finding suggests a link between genetic variants in the cannabinoid receptor type 1 (CNR1) gene, which encodes CB1 receptors and is expressed widely in the central and peripheral systems, and cannabis playing a role in the multifactorial pathogenesis of psychosis [2]. However, how the genetic variants interact with lifetime cannabis use and other environmental risk factors, such as childhood trauma, underlying psychosis remains challenging. Objective: To investigate whether there are associations of gene and environmental factors with psychosis, as well as G×E interactions in the relationship between lifetime cannabis use, childhood trauma, and single nucleotide variants (SNVs) of CNR1 and psychosis in a Brazilian sample. Methods: In a population-based case-control study nested in an incident study (STREAM, Brazil) [3], part of the WP2 EU-GEI consortium, 143 first-episode psychosis patients (FEPp) and 286 community-based controls of both sexes, aged between 16 and 64 years, were included over a period of three years. Thirteen SNVs of CNR1 gene (rs806380, rs806379, rs1049353, rs6454674, rs1535255, rs2023239, rs12720071, rs6928499, rs806374, rs7766029, rs806378, rs10485170, rs9450898), were genotyped from peripheral blood DNA using a custom Illumina HumanCoreExome-24 BeadChip genotyping arrays (GWAS Cardiff chip). Environmental adversities were evaluated using the Cannabis Experience and the Childhood Trauma Questionnaires. Data were analysed using a binary logistic regression model (Adj OR, 95% CI), including a binary outcome (community-based controls and FEPp), adjusted by sex, age, skin colour, years of education and tobacco smoking. Genotype frequencies were analysed under the dominant model (homozygous ancestral x heterozygous + homozygous variant). The significance level was set at α≤0.05. Results: Lifetime cannabis use and childhood trauma increased the risk for psychosis (OR=3.7; 2.6-6.195% CI, p<0.001; OR=3.0; 1.9-4.7 95% CI, p<0.001, respectively). We also showed that the presence of CNR1 rs12720071-T-allele moderated the association between lifetime cannabis use and psychosis (OR=6.0; 2.0-17.5 95% CI; p=0.001). Moreover, the combination of CNR1 rs12720071-T-allele carriers with childhood trauma also suggests a change in the risk of psychosis (OR=3.6; 1.4-9.0 95% CI; p=0.006). No significant associations between the environmental factors and other SNVs were found. Conclusions: We demonstrated a significant interaction between CNR1 rs12720071 SNV and two important environmental risk factors in their association with psychosis. T allele carriers of CNR1 rs12720071 had a higher risk of psychosis when lifetime cannabis use or childhood trauma were present. Our results suggest a G×E interaction involving the CNR1 gene, trauma and cannabis in psychosis. We will explore the associations between genetic and epigenetic markers of the CNR1 gene with environmental factors in larger and longer follow-up cohorts to better understand the mechanisms of endocannabinoid system dysfunction in the etiology of psychosis

    Social disadvantage, linguistic distance, ethnic minority status and first-episode psychosis: Results from the EU-GEI case-control study

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    BackgroundEthnic minority groups in Western countries face an increased risk of psychotic disorders. Causes of this long-standing public health inequality remain poorly understood. We investigated whether social disadvantage, linguistic distance and discrimination contributed to these patterns.MethodsWe used case-control data from the EUropean network of national schizophrenia networks studying Gene-Environment Interactions (EU-GEI) study, carried out in 16 centres in six countries. We recruited 1130 cases and 1497 population-based controls. Our main outcome measure was first-episode ICD-10 psychotic disorder (F20-F33), and exposures were ethnicity (white majority, black, mixed, Asian, North-African, white minority and other), generational status, social disadvantage, linguistic distance and discrimination. Age, sex, paternal age, cannabis use, childhood trauma and parental history of psychosis were included as a priori confounders. Exposures and confounders were added sequentially to multivariable logistic models, following multiple imputation for missing data.ResultsParticipants from any ethnic minority background had crude excess odds of psychosis [odds ratio (OR) 2.03, 95% confidence interval (CI) 1.69-2.43], which remained after adjustment for confounders (OR 1.61, 95% CI 1.31-1.98). This was progressively attenuated following further adjustment for social disadvantage (OR 1.52, 95% CI 1.22-1.89) and linguistic distance (OR 1.22, 95% CI 0.95-1.57), a pattern mirrored in several specific ethnic groups. Linguistic distance and social disadvantage had stronger effects for first- A nd later-generation groups, respectively.ConclusionSocial disadvantage and linguistic distance, two potential markers of sociocultural exclusion, were associated with increased odds of psychotic disorder, and adjusting for these led to equivocal risk between several ethnic minority groups and the white majority

    Jumping to conclusions, general intelligence, and psychosis liability: Findings from the multi-centre EU-GEI case-control study

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    BackgroundThe 'jumping to conclusions' (JTC) bias is associated with both psychosis and general cognition but their relationship is unclear. In this study, we set out to clarify the relationship between the JTC bias, IQ, psychosis and polygenic liability to schizophrenia and IQ.MethodsA total of 817 first episode psychosis patients and 1294 population-based controls completed assessments of general intelligence (IQ), and JTC, and provided blood or saliva samples from which we extracted DNA and computed polygenic risk scores for IQ and schizophrenia.ResultsThe estimated proportion of the total effect of case/control differences on JTC mediated by IQ was 79%. Schizophrenia polygenic risk score was non-significantly associated with a higher number of beads drawn (B = 0.47, 95% CI-0.21 to 1.16, p = 0.17); whereas IQ PRS (B = 0.51, 95% CI 0.25-0.76, p &lt; 0.001) significantly predicted the number of beads drawn, and was thus associated with reduced JTC bias. The JTC was more strongly associated with the higher level of psychotic-like experiences (PLEs) in controls, including after controlling for IQ (B =-1.7, 95% CI-2.8 to-0.5, p = 0.006), but did not relate to delusions in patients.ConclusionsOur findings suggest that the JTC reasoning bias in psychosis might not be a specific cognitive deficit but rather a manifestation or consequence, of general cognitive impairment. Whereas, in the general population, the JTC bias is related to PLEs, independent of IQ. The work has the potential to inform interventions targeting cognitive biases in early psychosis

    Measurement of the polarisation of W bosons produced with large transverse momentum in pp collisions at sqrt(s) = 7 TeV with the ATLAS experiment

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    This paper describes an analysis of the angular distribution of W->enu and W->munu decays, using data from pp collisions at sqrt(s) = 7 TeV recorded with the ATLAS detector at the LHC in 2010, corresponding to an integrated luminosity of about 35 pb^-1. Using the decay lepton transverse momentum and the missing transverse energy, the W decay angular distribution projected onto the transverse plane is obtained and analysed in terms of helicity fractions f0, fL and fR over two ranges of W transverse momentum (ptw): 35 < ptw < 50 GeV and ptw > 50 GeV. Good agreement is found with theoretical predictions. For ptw > 50 GeV, the values of f0 and fL-fR, averaged over charge and lepton flavour, are measured to be : f0 = 0.127 +/- 0.030 +/- 0.108 and fL-fR = 0.252 +/- 0.017 +/- 0.030, where the first uncertainties are statistical, and the second include all systematic effects.Comment: 19 pages plus author list (34 pages total), 9 figures, 11 tables, revised author list, matches European Journal of Physics C versio

    Observation of a new chi_b state in radiative transitions to Upsilon(1S) and Upsilon(2S) at ATLAS

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    The chi_b(nP) quarkonium states are produced in proton-proton collisions at the Large Hadron Collider (LHC) at sqrt(s) = 7 TeV and recorded by the ATLAS detector. Using a data sample corresponding to an integrated luminosity of 4.4 fb^-1, these states are reconstructed through their radiative decays to Upsilon(1S,2S) with Upsilon->mu+mu-. In addition to the mass peaks corresponding to the decay modes chi_b(1P,2P)->Upsilon(1S)gamma, a new structure centered at a mass of 10.530+/-0.005 (stat.)+/-0.009 (syst.) GeV is also observed, in both the Upsilon(1S)gamma and Upsilon(2S)gamma decay modes. This is interpreted as the chi_b(3P) system.Comment: 5 pages plus author list (18 pages total), 2 figures, 1 table, corrected author list, matches final version in Physical Review Letter
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