565 research outputs found

    Symptoms of major depression: Their stability, familiality, and prediction by genetic, temperamental, and childhood environmental risk factors

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    Background: Psychiatry has long sought to develop biological diagnostic subtypes based on symptomatic differences. This effort assumes that symptoms reflect, with good fidelity, underlying etiological processes. We address this question for major depression (MD). Methods: We examine, in twins from a population-based registry, similarity in symptom endorsement in individuals meeting criteria for last-year MD at separate interview waves and in concordant twin pairs. Among individuals with MD, we explore the impact of genetic-temperamental and child adversity risk factors on individual reported symptoms. Aggregated criteria do not separate insomnia from hypersomnia, weight gain from loss, etc. while disaggregated criteria do. Results: In twins with MD at two different waves, the mean tetrachoric correlations (+/- SEM) for aggregated and disaggregated DSM-IV A criteria were, respectively, + 0.31 +/- 0.06 and + 0.34 +/- 0.03. In monozygotic (MZ) and dizygotic (DZ) twin pairs concordant for last-year MD, the mean tetrachoric correlations for aggregated and disaggregated criteria were, respectively, + 0.33 +/- 0.07 and + 0.43 +/- 0.04, and + 0.05 +/- 0.08 and + 0.07 +/- 0.04. In individuals meeting MD criteria, neuroticism predicted the most MD symptoms (10), followed by childhood sexual abuse (8), low parental warmth (6), and genetic risk (4). Conclusions: The correlations for individual depressive symptoms over multiple episodes and within MZ twins concordant for MD are modest suggesting the important role of transient influences. The multidetermination of individual symptoms was further evidenced by their prediction by personality and exposure to early life adversities. The multiple factors influencing symptomatic presentation inMDmay contribute to our difficulties in isolating clinical depressive subtypes with distinct pathophysiologies

    Evaluation of a new trauma-related drinking to cope measure: Latent structure and heritability

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    Posttraumatic stress disorder (PTSD) and alcohol use disorder (AUD) commonly co-occur, share latent genetic risk, and are associated with many negative public health outcomes. Via a self-medication framework, trauma-related drinking to cope (TRD), an unexplored phenotype to date, may help explain why these two disorders co-occur, thus serving as an essential target for treatment and prevention efforts. This study sought to create a novel measure of TRD and to investigate its indirect influences on the association between PTSD and AUD, as well as its potential shared molecular genetic risk with PTSD in a genetically-informative study of college students. A sample of 1,896 undergraduate students with a history of trauma and alcohol use provided genotypic data and completed an online assessment battery. The psychometric properties of TRD and how it relates to relevant constructs were examined using descriptive statistics and structural equation modeling. Results of a correlated multiple mediator model indicated that, while accounting for the effects of generalized drinking motives, TRD partially mediated the relation between PTSD and alcohol use problems (β = 0.213, p \u3c .001), consistent with the self-medication hypothesis, and that this relationship was stronger for males (β = 0.804, p \u3c .001) than for females (β = 0.463, p \u3c .001). Results were substantiated using longitudinal data. Genotypic analyses to be presented will include univariate genome wide complex trait analyses (GCTA) to establish SNP-based heritability associated with TRD and PTSD, separately, as well as bivariate GCTA to examine potential overlap in heritability between TRD and PTSD.https://scholarscompass.vcu.edu/gradposters/1047/thumbnail.jp

    The Genetic and Environmental Sources of Resemblance Between Normative Personality and Personality Disorder Traits

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    Recent work has suggested a high level of congruence between normative personality, most typically represented by the big five factors, and abnormal personality traits. In 2,293 Norwegian adult twins ascertained from a population-based registry, the authors evaluated the degree of sharing of genetic and environmental influences on normative personality, assessed by the Big Five Inventory (BFI), and personality disorder traits (PDTs), assessed by the Personality Inventory for DSM-S-Norwegian Brief Form (PID-5NBF). For four of the five BFI dimensions, the strongest genetic correlation was observed with the expected PID-5-NBF dimension (e.g., neuroticism with negative affectivity [+], conscientiousness with disinhibition [-]). However, neuroticism, conscientiousness, and agreeableness had substantial genetic correlations with other PID-S-NBF dimensions (e.g., neuroticism with compulsivity [+], agreeableness with detachment [-]). Openness had no substantial genetic correlations with any PID-5-NBF dimension. The proportion of genetic risk factors shared in aggregate between the BFI traits and the PID-5-NBF dimensions was quite high for conscientiousness and neuroticism, relatively robust for extraversion and agreeableness, but quite low for openness. Of the six PID-S-NBF dimensions, three (negative affectivity, detachment, and disinhibition) shared, in aggregate, most of their genetic risk factors with normative personality traits. Genetic factors underlying psychoticism, antagonism, and compulsivity were shared to a lesser extent, suggesting that they are influenced by etiological factors not well indexed by the BFI

    Genetic and Environmental Structure of DSM-IV Criteria for Antisocial Personality Disorder: A Twin Study

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    Results from previous studies on DSM-IV and DSM-5 Antisocial Personality Disorder (ASPD) have suggested that the construct is etiologically multidimensional. To our knowledge, however, the structure of genetic and environmental influences in ASPD has not been examined using an appropriate range of biometric models and diagnostic interviews. The 7 ASPD criteria (section A) were assessed in a population-based sample of 2794 Norwegian twins by a structured interview for DSM-IV personality disorders. Exploratory analyses were conducted at the phenotypic level. Multivariate biometric models, including both independent and common pathways, were compared. A single phenotypic factor was found, and the best-fitting biometric model was a single-factor common pathway model, with common-factor heritability of 51% (95% CI 40–67%). In other words, both genetic and environmental correlations between the ASPD criteria could be accounted for by a single common latent variable. The findings support the validity of ASPD as a unidimensional diagnostic construct

    The Impact Of Technology And Teachers\u27 Perceptions Of Changes In Student Learning

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    Today’s cell phones are small computers in their own right, many having the capability of Internet searching and downloading information, exchanging data, taking and storing pictures, and its most popular function with the current generation of young people: text messaging. While on the surface it appears that text messaging has brought users together and improved communication, its effects on learning and social relationships are cause for concern. Personal interviews and online surveys conducted with over 100 educators present a real and sometimes disturbing look at new challenges in teaching and communicating with today’s students. Reading and writing ability is declining, as well as the ability of maintaining personal relationships. Social presence theory, media richness theory, and Social information processing theory, as well as nonverbal communication, all play an active role in the new communication habits that are common with text messaging. The importance of understanding digital communication and teaching with technology is vital in order for our students to maintain a competitive edge in their educational success and relationships during their school years and beyond; but future success also depends on their ability to communicate thoughts and ideas beyond digital capabilities, even in today’s fast-paced technologically-driven society. The findings within this study note the adaptability of educators as they face new challenges incorporating technology into education. Conversely, students are falling into a more silent type of communication; one that not only threatens to destroy their reading and writing ability within their school years and beyond, but one that could also seriously threaten their chances of creating and enjoying positive relationships

    Gas emissions, minerals, and tars associated with three coal fires, Powder River Basin, USA.

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    Ground-based surveys of three coal fires and airborne surveys of two of the fires were conducted near Sheridan, Wyoming. The fires occur in natural outcrops and in abandoned mines, all containing Paleocene-age subbituminous coals. Diffuse (carbon dioxide (CO(2)) only) and vent (CO(2), carbon monoxide (CO), methane, hydrogen sulfide (H(2)S), and elemental mercury) emission estimates were made for each of the fires. Additionally, gas samples were collected for volatile organic compound (VOC) analysis and showed a large range in variation between vents. The fires produce locally dangerous levels of CO, CO(2), H(2)S, and benzene, among other gases. At one fire in an abandoned coal mine, trends in gas and tar composition followed a change in topography. Total CO(2) fluxes for the fires from airborne, ground-based, and rate of fire advancement estimates ranged from 0.9 to 780mg/s/m(2) and are comparable to other coal fires worldwide. Samples of tar and coal-fire minerals collected from the mouth of vents provided insight into the behavior and formation of the coal fires

    Network Psychometrics

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    This chapter provides a general introduction of network modeling in psychometrics. The chapter starts with an introduction to the statistical model formulation of pairwise Markov random fields (PMRF), followed by an introduction of the PMRF suitable for binary data: the Ising model. The Ising model is a model used in ferromagnetism to explain phase transitions in a field of particles. Following the description of the Ising model in statistical physics, the chapter continues to show that the Ising model is closely related to models used in psychometrics. The Ising model can be shown to be equivalent to certain kinds of logistic regression models, loglinear models and multi-dimensional item response theory (MIRT) models. The equivalence between the Ising model and the MIRT model puts standard psychometrics in a new light and leads to a strikingly different interpretation of well-known latent variable models. The chapter gives an overview of methods that can be used to estimate the Ising model, and concludes with a discussion on the interpretation of latent variables given the equivalence between the Ising model and MIRT.Comment: In Irwing, P., Hughes, D., and Booth, T. (2018). The Wiley Handbook of Psychometric Testing, 2 Volume Set: A Multidisciplinary Reference on Survey, Scale and Test Development. New York: Wile

    ACSL6 Is Associated with the Number of Cigarettes Smoked and Its Expression Is Altered by Chronic Nicotine Exposure

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    Individuals with schizophrenia tend to be heavy smokers and are at high risk for tobacco dependence. However, the nature of the comorbidity is not entirely clear. We previously reported evidence for association of schizophrenia with SNPs and SNP haplotypes in a region of chromosome 5q containing the SPEC2, PDZ-GEF2 and ACSL6 genes. In this current study, analysis of the control subjects of the Molecular Genetics of Schizophrenia (MGS) sample showed similar pattern of association with number of cigarettes smoked per day (numCIG) for the same region. To further test if this locus is associated with tobacco smoking as measured by numCIG and FTND, we conducted replication and meta-analysis in 12 independent samples (n\u3e16,000) for two markers in ACSL6 reported in our previous schizophrenia study. In the meta-analysis of the replication samples, we found that rs667437 and rs477084 were significantly associated with numCIG (p = 0.00038 and 0.00136 respectively) but not with FTND scores. We then used in vitro and in vivo techniques to test if nicotine exposure influences the expression of ACSL6 in brain. Primary cortical culture studies showed that chronic (5-day) exposure to nicotine stimulated ACSL6 mRNA expression. Fourteen days of nicotine administration via osmotic mini pump also increased ACSL6 protein levels in the prefrontal cortex and hippocampus of mice. These increases were suppressed by injection of the nicotinic receptor antagonist mecamylamine, suggesting that elevated expression ofACSL6 requires nicotinic receptor activation. These findings suggest that variations in theACSL6 gene may contribute to the quantity of cigarettes smoked. The independent associations of this locus with schizophrenia and with numCIG in non-schizophrenic subjects suggest that this locus may be a common liability to both conditions
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