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

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

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

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

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

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

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]

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

The continuity of effect of schizophrenia polygenic risk score and patterns of cannabis use on transdiagnostic symptom dimensions at first-episode psychosis: findings from the EU-GEI study

Diagnostic categories do not completely reflect the heterogeneous expression of psychosis. Using data from the EU-GEI study, we evaluated the impact of schizophrenia polygenic risk score (SZ-PRS) and patterns of cannabis use on the transdiagnostic expression of psychosis. We analysed first-episode psychosis patients (FEP) and controls, generating transdiagnostic dimensions of psychotic symptoms and experiences using item response bi-factor modelling. Linear regression was used to test the associations between these dimensions and SZ-PRS, as well as the combined effect of SZ-PRS and cannabis use on the dimensions of positive psychotic symptoms and experiences. We found associations between SZ-PRS and (1) both negative (B = 0.18; 95%CI 0.03–0.33) and positive (B = 0.19; 95%CI 0.03–0.35) symptom dimensions in 617 FEP patients, regardless of their categorical diagnosis; and (2) all the psychotic experience dimensions in 979 controls. We did not observe associations between SZ-PRS and the general and affective dimensions in FEP. Daily and current cannabis use were associated with the positive dimensions in FEP (B = 0.31; 95%CI 0.11–0.52) and in controls (B = 0.26; 95%CI 0.06–0.46), over and above SZ-PRS. We provide evidence that genetic liability to schizophrenia and cannabis use map onto transdiagnostic symptom dimensions, supporting the validity and utility of the dimensional representation of psychosis. In our sample, genetic liability to schizophrenia correlated with more severe psychosis presentation, and cannabis use conferred risk to positive symptomatology beyond the genetic risk. Our findings support the hypothesis that psychotic experiences in the general population have similar genetic substrates as clinical disorders

Animal defense strategies and anxiety disorders

Anxiety disorders are classified according to symptoms, time course and therapeutic response. Concurrently, the experimental analysis of defensive behavior has identified three strategies of defense that are shared by different animal species, triggered by situations of potential, distal and proximal predatory threat, respectively. The first one consists of cautious exploration of the environment for risk assessment. The associated emotion is supposed to be anxiety and its pathology, Generalized Anxiety Disorder. The second is manifested by oriented escape or by behavioral inhibition, being related to normal fear and to Specific Phobias, as disorders. The third consists of disorganized flight or complete immobility, associated to dread and Panic Disorder. Among conspecific interactions lies a forth defense strategy, submission, that has been related to normal social anxiety (shyness) and to Social Anxiety Disorder. In turn, Posttraumatic Stress Disorder and Obsessive-Compulsive Disorder do not seem to be directly related to innate defense reactions. Such evolutionary approach offers a reliable theoretical framework for the study of the biological determinants of anxiety disorders, and a sound basis for psychiatric classification

INTERACTION AMONG ZINC, GLUCOSE, and INSULIN in NORMAL INDIVIDUALS DURING GLUCOSE and TOLBUTAMIDE PERFUSION

Reports in the literature have shown that acute or chronic zinc administration may cause hyperglycemia, with a fall in serum or insular insulin occurring in experimental animals. On the other hand, under conditions of both acute and chronic hyperglycemia, an increase, a decrease, or a normal level of blood zinc has been observed in studies conducted on humans. Thus, the objective of the investigation described here was to determine the relationship existing among zinc, glucose, and insulin under acute conditions. Thirty-six subjects of both sexes (mean age, 23 yr) were tested at 7:00 A.M. after a 12-h fast. Two antecubital veins of both forearms were punctured and maintained with physiological saline. Three experiments were performed in which zinc was administered orally, and hypertonic glucose and tolbutamid were administered intravenously. Blood samples were then collected over a period ranging from 93 to 240 min after the basal times of - 30 and 0 min. Hyperzincemia did not cause changes in plasma glucose or insulin either in the absence of or during perfusion of glucose. Hyperglycemia, hypoglycemia, and hyperinsulinemia did not modify serum zinc levels. These results demonstrate that acute zinc administration did not change carbohydrate metabolism and that sudden variations in glucose and insulin levels did not modify the serum profile of zinc.UNIV São Paulo,FAC CIENCIAS FARMACEUT RIBEIRAO PRETO,BR-14049 RIBEIRAO PRETO,SP,BRAZILESCOLA PAULISTA MED SCH,BR-04023 São Paulo,BRAZILESCOLA PAULISTA MED SCH,BR-04023 São Paulo,BRAZILWeb of Scienc