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Genetic and environmental contributions to cannabis dependence in a national young adult twin sample
- M. T. LYNSKEY, A. C. HEATH, E. C. NELSON, K. K. BUCHOLZ, P. A. F. MADDEN, W. S. SLUTSKE, D. J. STATHAM, N. G. MARTIN
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- Journal:
- Psychological Medicine / Volume 32 / Issue 2 / February 2002
- Published online by Cambridge University Press:
- 08 April 2017, pp. 195-207
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Background. This paper examines genetic and environmental contributions to risk of cannabis dependence.
Method. Symptoms of cannabis dependence and measures of social, family and individual risk factors were assessed in a sample of 6265 young adult male and female Australian twins born 1964–1971.
Results. Symptoms of cannabis dependence were common: 11·0% of sample (15·1% of men and 7·8% of women) reported two or more symptoms of dependence. Correlates of cannabis dependence included educational attainment, exposure to parental conflict, sexual abuse, major depression, social anxiety and childhood conduct disorder. However, even after control for the effects of these factors, there was evidence of significant genetic effects on risk of cannabis dependence. Standard genetic modelling indicated that 44·7% (95% CI = 15–72·2) of the variance in liability to cannabis dependence could be accounted for by genetic factors, 20·1% (95% CI = 0–43·6) could be attributed to shared environment factors and 35·3% (95% CI = 26·4–45·7) could be attributed to non-shared environmental factors. However, while there was no evidence of significant gender differences in the magnitude of genetic and environmental influences, a model which assumed both genetic and shared environmental influences on risks of cannabis dependence among men and shared environmental but no genetic influences among women provided an equally good fit to the data.
Conclusions. There was consistent evidence that genetic risk factors are important determinants of risk of cannabis dependence among men. However, it remains uncertain whether there are genetic influences on liability to cannabis dependence among women.
Sequential sampling: a novel method in farm animal welfare assessment
- C. A. E. Heath, D. C. J. Main, S. Mullan, M. J. Haskell, W. J. Browne
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Lameness in dairy cows is an important welfare issue. As part of a welfare assessment, herd level lameness prevalence can be estimated from scoring a sample of animals, where higher levels of accuracy are associated with larger sample sizes. As the financial cost is related to the number of cows sampled, smaller samples are preferred. Sequential sampling schemes have been used for informing decision making in clinical trials. Sequential sampling involves taking samples in stages, where sampling can stop early depending on the estimated lameness prevalence. When welfare assessment is used for a pass/fail decision, a similar approach could be applied to reduce the overall sample size. The sampling schemes proposed here apply the principles of sequential sampling within a diagnostic testing framework. This study develops three sequential sampling schemes of increasing complexity to classify 80 fully assessed UK dairy farms, each with known lameness prevalence. Using the Welfare Quality herd-size-based sampling scheme, the first ‘basic’ scheme involves two sampling events. At the first sampling event half the Welfare Quality sample size is drawn, and then depending on the outcome, sampling either stops or is continued and the same number of animals is sampled again. In the second ‘cautious’ scheme, an adaptation is made to ensure that correctly classifying a farm as ‘bad’ is done with greater certainty. The third scheme is the only scheme to go beyond lameness as a binary measure and investigates the potential for increasing accuracy by incorporating the number of severely lame cows into the decision. The three schemes are evaluated with respect to accuracy and average sample size by running 100 000 simulations for each scheme, and a comparison is made with the fixed size Welfare Quality herd-size-based sampling scheme. All three schemes performed almost as well as the fixed size scheme but with much smaller average sample sizes. For the third scheme, an overall association between lameness prevalence and the proportion of lame cows that were severely lame on a farm was found. However, as this association was found to not be consistent across all farms, the sampling scheme did not prove to be as useful as expected. The preferred scheme was therefore the ‘cautious’ scheme for which a sampling protocol has also been developed.
Missouri Mothers and Their Children: A Family Study of the Effects of Genetics and the Prenatal Environment
- Valerie S. Knopik, Andrew C. Heath, Kristine Marceau, Rohan H. C. Palmer, John E. McGeary, Alexandre Todorov, Allison Schettini Evans
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- Journal:
- Twin Research and Human Genetics / Volume 18 / Issue 5 / October 2015
- Published online by Cambridge University Press:
- 29 July 2015, pp. 485-496
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The Missouri Mothers and Their Children Study (MO-MATCH) was specifically designed to critically investigate prenatal environmental influences on child attention problems and associated learning and cognitive deficits. The project began as a pilot study in 2004 and was formally launched in 2008. Participants in the study were initially identified via the Department of Vital Statistics birth record (BR) database. Interview and lab-based data were obtained from: (1) mothers of Missouri-born children (born 1998–2005), who smoked during one pregnancy but not during another pregnancy; (2) biological fathers when available; and (3) the children (i.e., full sibling pairs discordant for exposure to maternal smoking during pregnancy (SDP). This within-mother, between-pregnancy contrast provides the best possible methodological control for many stable maternal and familial confounding factors (e.g., heritable and socio-demographic characteristics of the mother that predict increased probability of SDP). It also controls for differences between mothers who do and do not smoke during pregnancy, and their partners, that might otherwise artifactually create, or alternatively mask, associations between SDP and child outcomes. Such a design will therefore provide opportunities to determine less biased effect sizes while also allowing us to investigate (on a preliminary basis) the possible contribution of paternal or other second-hand smoke exposure during the pre, peri, and postnatal periods to offspring outcome. This protocol has developed a cohort that can be followed longitudinally through periods typically associated with increased externalizing symptoms and substance used initiation.
Contributors
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- By Mitchell Aboulafia, Frederick Adams, Marilyn McCord Adams, Robert M. Adams, Laird Addis, James W. Allard, David Allison, William P. Alston, Karl Ameriks, C. Anthony Anderson, David Leech Anderson, Lanier Anderson, Roger Ariew, David Armstrong, Denis G. Arnold, E. J. Ashworth, Margaret Atherton, Robin Attfield, Bruce Aune, Edward Wilson Averill, Jody Azzouni, Kent Bach, Andrew Bailey, Lynne Rudder Baker, Thomas R. Baldwin, Jon Barwise, George Bealer, William Bechtel, Lawrence C. Becker, Mark A. Bedau, Ernst Behler, José A. Benardete, Ermanno Bencivenga, Jan Berg, Michael Bergmann, Robert L. Bernasconi, Sven Bernecker, Bernard Berofsky, Rod Bertolet, Charles J. Beyer, Christian Beyer, Joseph Bien, Joseph Bien, Peg Birmingham, Ivan Boh, James Bohman, Daniel Bonevac, Laurence BonJour, William J. Bouwsma, Raymond D. Bradley, Myles Brand, Richard B. Brandt, Michael E. Bratman, Stephen E. Braude, Daniel Breazeale, Angela Breitenbach, Jason Bridges, David O. Brink, Gordon G. Brittan, Justin Broackes, Dan W. Brock, Aaron Bronfman, Jeffrey E. Brower, Bartosz Brozek, Anthony Brueckner, Jeffrey Bub, Lara Buchak, Otavio Bueno, Ann E. Bumpus, Robert W. Burch, John Burgess, Arthur W. Burks, Panayot Butchvarov, Robert E. Butts, Marina Bykova, Patrick Byrne, David Carr, Noël Carroll, Edward S. Casey, Victor Caston, Victor Caston, Albert Casullo, Robert L. Causey, Alan K. L. Chan, Ruth Chang, Deen K. Chatterjee, Andrew Chignell, Roderick M. Chisholm, Kelly J. Clark, E. J. Coffman, Robin Collins, Brian P. Copenhaver, John Corcoran, John Cottingham, Roger Crisp, Frederick J. Crosson, Antonio S. Cua, Phillip D. Cummins, Martin Curd, Adam Cureton, Andrew Cutrofello, Stephen Darwall, Paul Sheldon Davies, Wayne A. Davis, Timothy Joseph Day, Claudio de Almeida, Mario De Caro, Mario De Caro, John Deigh, C. F. Delaney, Daniel C. Dennett, Michael R. DePaul, Michael Detlefsen, Daniel Trent Devereux, Philip E. Devine, John M. Dillon, Martin C. Dillon, Robert DiSalle, Mary Domski, Alan Donagan, Paul Draper, Fred Dretske, Mircea Dumitru, Wilhelm Dupré, Gerald Dworkin, John Earman, Ellery Eells, Catherine Z. Elgin, Berent Enç, Ronald P. Endicott, Edward Erwin, John Etchemendy, C. Stephen Evans, Susan L. Feagin, Solomon Feferman, Richard Feldman, Arthur Fine, Maurice A. Finocchiaro, William FitzPatrick, Richard E. Flathman, Gvozden Flego, Richard Foley, Graeme Forbes, Rainer Forst, Malcolm R. Forster, Daniel Fouke, Patrick Francken, Samuel Freeman, Elizabeth Fricker, Miranda Fricker, Michael Friedman, Michael Fuerstein, Richard A. Fumerton, Alan Gabbey, Pieranna Garavaso, Daniel Garber, Jorge L. A. Garcia, Robert K. Garcia, Don Garrett, Philip Gasper, Gerald Gaus, Berys Gaut, Bernard Gert, Roger F. Gibson, Cody Gilmore, Carl Ginet, Alan H. Goldman, Alvin I. Goldman, Alfonso Gömez-Lobo, Lenn E. Goodman, Robert M. Gordon, Stefan Gosepath, Jorge J. E. Gracia, Daniel W. Graham, George A. Graham, Peter J. Graham, Richard E. Grandy, I. Grattan-Guinness, John Greco, Philip T. Grier, Nicholas Griffin, Nicholas Griffin, David A. Griffiths, Paul J. Griffiths, Stephen R. Grimm, Charles L. Griswold, Charles B. Guignon, Pete A. Y. Gunter, Dimitri Gutas, Gary Gutting, Paul Guyer, Kwame Gyekye, Oscar A. Haac, Raul Hakli, Raul Hakli, Michael Hallett, Edward C. Halper, Jean Hampton, R. James Hankinson, K. R. Hanley, Russell Hardin, Robert M. Harnish, William Harper, David Harrah, Kevin Hart, Ali Hasan, William Hasker, John Haugeland, Roger Hausheer, William Heald, Peter Heath, Richard Heck, John F. Heil, Vincent F. Hendricks, Stephen Hetherington, Francis Heylighen, Kathleen Marie Higgins, Risto Hilpinen, Harold T. Hodes, Joshua Hoffman, Alan Holland, Robert L. Holmes, Richard Holton, Brad W. Hooker, Terence E. Horgan, Tamara Horowitz, Paul Horwich, Vittorio Hösle, Paul Hoβfeld, Daniel Howard-Snyder, Frances Howard-Snyder, Anne Hudson, Deal W. Hudson, Carl A. Huffman, David L. Hull, Patricia Huntington, Thomas Hurka, Paul Hurley, Rosalind Hursthouse, Guillermo Hurtado, Ronald E. Hustwit, Sarah Hutton, Jonathan Jenkins Ichikawa, Harry A. Ide, David Ingram, Philip J. Ivanhoe, Alfred L. Ivry, Frank Jackson, Dale Jacquette, Joseph Jedwab, Richard Jeffrey, David Alan Johnson, Edward Johnson, Mark D. Jordan, Richard Joyce, Hwa Yol Jung, Robert Hillary Kane, Tomis Kapitan, Jacquelyn Ann K. Kegley, James A. Keller, Ralph Kennedy, Sergei Khoruzhii, Jaegwon Kim, Yersu Kim, Nathan L. King, Patricia Kitcher, Peter D. Klein, E. D. Klemke, Virginia Klenk, George L. Kline, Christian Klotz, Simo Knuuttila, Joseph J. Kockelmans, Konstantin Kolenda, Sebastian Tomasz Kołodziejczyk, Isaac Kramnick, Richard Kraut, Fred Kroon, Manfred Kuehn, Steven T. Kuhn, Henry E. Kyburg, John Lachs, Jennifer Lackey, Stephen E. Lahey, Andrea Lavazza, Thomas H. Leahey, Joo Heung Lee, Keith Lehrer, Dorothy Leland, Noah M. Lemos, Ernest LePore, Sarah-Jane Leslie, Isaac Levi, Andrew Levine, Alan E. Lewis, Daniel E. Little, Shu-hsien Liu, Shu-hsien Liu, Alan K. L. Chan, Brian Loar, Lawrence B. Lombard, John Longeway, Dominic McIver Lopes, Michael J. Loux, E. J. Lowe, Steven Luper, Eugene C. Luschei, William G. Lycan, David Lyons, David Macarthur, Danielle Macbeth, Scott MacDonald, Jacob L. Mackey, Louis H. Mackey, Penelope Mackie, Edward H. Madden, Penelope Maddy, G. B. Madison, Bernd Magnus, Pekka Mäkelä, Rudolf A. Makkreel, David Manley, William E. Mann (W.E.M.), Vladimir Marchenkov, Peter Markie, Jean-Pierre Marquis, Ausonio Marras, Mike W. Martin, A. P. Martinich, William L. McBride, David McCabe, Storrs McCall, Hugh J. McCann, Robert N. McCauley, John J. McDermott, Sarah McGrath, Ralph McInerny, Daniel J. McKaughan, Thomas McKay, Michael McKinsey, Brian P. McLaughlin, Ernan McMullin, Anthonie Meijers, Jack W. Meiland, William Jason Melanson, Alfred R. Mele, Joseph R. Mendola, Christopher Menzel, Michael J. Meyer, Christian B. Miller, David W. Miller, Peter Millican, Robert N. Minor, Phillip Mitsis, James A. Montmarquet, Michael S. Moore, Tim Moore, Benjamin Morison, Donald R. Morrison, Stephen J. Morse, Paul K. Moser, Alexander P. D. Mourelatos, Ian Mueller, James Bernard Murphy, Mark C. Murphy, Steven Nadler, Jan Narveson, Alan Nelson, Jerome Neu, Samuel Newlands, Kai Nielsen, Ilkka Niiniluoto, Carlos G. Noreña, Calvin G. Normore, David Fate Norton, Nikolaj Nottelmann, Donald Nute, David S. Oderberg, Steve Odin, Michael O’Rourke, Willard G. Oxtoby, Heinz Paetzold, George S. Pappas, Anthony J. Parel, Lydia Patton, R. P. Peerenboom, Francis Jeffry Pelletier, Adriaan T. Peperzak, Derk Pereboom, Jaroslav Peregrin, Glen Pettigrove, Philip Pettit, Edmund L. Pincoffs, Andrew Pinsent, Robert B. Pippin, Alvin Plantinga, Louis P. Pojman, Richard H. Popkin, John F. Post, Carl J. Posy, William J. Prior, Richard Purtill, Michael Quante, Philip L. Quinn, Philip L. Quinn, Elizabeth S. Radcliffe, Diana Raffman, Gerard Raulet, Stephen L. Read, Andrews Reath, Andrew Reisner, Nicholas Rescher, Henry S. Richardson, Robert C. Richardson, Thomas Ricketts, Wayne D. Riggs, Mark Roberts, Robert C. Roberts, Luke Robinson, Alexander Rosenberg, Gary Rosenkranz, Bernice Glatzer Rosenthal, Adina L. Roskies, William L. Rowe, T. M. Rudavsky, Michael Ruse, Bruce Russell, Lilly-Marlene Russow, Dan Ryder, R. M. Sainsbury, Joseph Salerno, Nathan Salmon, Wesley C. Salmon, Constantine Sandis, David H. Sanford, Marco Santambrogio, David Sapire, Ruth A. Saunders, Geoffrey Sayre-McCord, Charles Sayward, James P. Scanlan, Richard Schacht, Tamar Schapiro, Frederick F. Schmitt, Jerome B. Schneewind, Calvin O. Schrag, Alan D. Schrift, George F. Schumm, Jean-Loup Seban, David N. Sedley, Kenneth Seeskin, Krister Segerberg, Charlene Haddock Seigfried, Dennis M. Senchuk, James F. Sennett, William Lad Sessions, Stewart Shapiro, Tommie Shelby, Donald W. Sherburne, Christopher Shields, Roger A. Shiner, Sydney Shoemaker, Robert K. Shope, Kwong-loi Shun, Wilfried Sieg, A. John Simmons, Robert L. Simon, Marcus G. Singer, Georgette Sinkler, Walter Sinnott-Armstrong, Matti T. Sintonen, Lawrence Sklar, Brian Skyrms, Robert C. Sleigh, Michael Anthony Slote, Hans Sluga, Barry Smith, Michael Smith, Robin Smith, Robert Sokolowski, Robert C. Solomon, Marta Soniewicka, Philip Soper, Ernest Sosa, Nicholas Southwood, Paul Vincent Spade, T. L. S. Sprigge, Eric O. Springsted, George J. Stack, Rebecca Stangl, Jason Stanley, Florian Steinberger, Sören Stenlund, Christopher Stephens, James P. Sterba, Josef Stern, Matthias Steup, M. A. Stewart, Leopold Stubenberg, Edith Dudley Sulla, Frederick Suppe, Jere Paul Surber, David George Sussman, Sigrún Svavarsdóttir, Zeno G. Swijtink, Richard Swinburne, Charles C. Taliaferro, Robert B. Talisse, John Tasioulas, Paul Teller, Larry S. Temkin, Mark Textor, H. S. Thayer, Peter Thielke, Alan Thomas, Amie L. Thomasson, Katherine Thomson-Jones, Joshua C. Thurow, Vzalerie Tiberius, Terrence N. Tice, Paul Tidman, Mark C. Timmons, William Tolhurst, James E. Tomberlin, Rosemarie Tong, Lawrence Torcello, Kelly Trogdon, J. D. Trout, Robert E. Tully, Raimo Tuomela, John Turri, Martin M. Tweedale, Thomas Uebel, Jennifer Uleman, James Van Cleve, Harry van der Linden, Peter van Inwagen, Bryan W. Van Norden, René van Woudenberg, Donald Phillip Verene, Samantha Vice, Thomas Vinci, Donald Wayne Viney, Barbara Von Eckardt, Peter B. M. Vranas, Steven J. Wagner, William J. Wainwright, Paul E. Walker, Robert E. Wall, Craig Walton, Douglas Walton, Eric Watkins, Richard A. Watson, Michael V. Wedin, Rudolph H. Weingartner, Paul Weirich, Paul J. Weithman, Carl Wellman, Howard Wettstein, Samuel C. Wheeler, Stephen A. White, Jennifer Whiting, Edward R. Wierenga, Michael Williams, Fred Wilson, W. Kent Wilson, Kenneth P. Winkler, John F. Wippel, Jan Woleński, Allan B. Wolter, Nicholas P. Wolterstorff, Rega Wood, W. Jay Wood, Paul Woodruff, Alison Wylie, Gideon Yaffe, Takashi Yagisawa, Yutaka Yamamoto, Keith E. Yandell, Xiaomei Yang, Dean Zimmerman, Günter Zoller, Catherine Zuckert, Michael Zuckert, Jack A. Zupko (J.A.Z.)
- Edited by Robert Audi, University of Notre Dame, Indiana
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- The Cambridge Dictionary of Philosophy
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- 05 August 2015
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- 27 April 2015, pp ix-xxx
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Navigating the iceberg: reducing the number of parameters within the Welfare Quality® assessment protocol for dairy cows
- C. A. E. Heath, W. J. Browne, S. Mullan, D. C. J. Main
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The Welfare Quality® protocols provide a multidimensional assessment of welfare, which is lengthy, and hence limited in terms of practicality. The aim of this study was to investigate potential ‘iceberg indicators’ which could reliably predict the overall classification as a means of reducing the length of time for an assessment and so increase the feasibility of the Welfare Quality® protocol as a multidimensional assessment of welfare. Full Welfare Quality® assessments were carried out on 92 dairy farms in England and Wales. The farms were all classified as Acceptable or Enhanced. Logistic regression models with cross validation were used to compare model fit for the overall classification on farms. ‘Absence of prolonged thirst’, on its own, was found to correctly classify farms 88% of the time. More generally, the inclusion of more measures in the models was not associated with greater predictive ability for the overall classification. Absence of prolonged thirst could thus, in theory, be considered to be an iceberg indicator for the Welfare Quality® protocol, and could reduce the length of time for a farm assessment to 15 min. Previous work has shown that the parameters within the Welfare Quality® protocol are important and relevant for welfare assessment. However, it is argued that the credibility of the published aggregation system is compromised by the finding that one resource measure (Absence of prolonged thirst) is a major driver for the overall classification. It is therefore suggested that the prominence of Absence of prolonged thirst in this role may be better understood as an unintended consequence of the published measure aggregation system rather than as reflecting a realistic iceberg indicator.
Imidazole-Based Solvents and Membranes for CO2 Capture Applications
- Jason E. Bara, Matthew S. Shannon, W. Jeffrey Horne, John W. Whitley, Haining Liu, David A. Wallace, Heath Turner, Sergey P. Verevkin, Nathan Brown, Greg Staab, Rene Kupfer
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- Journal:
- MRS Online Proceedings Library Archive / Volume 1673 / 2014
- Published online by Cambridge University Press:
- 30 July 2014, mrss14-1673-i02-08
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- 2014
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Imidazoles present a tunable, versatile and economical platform for the development of novel liquid solvents and polymer membranes for CO2 capture. An overview of our studies in this area is presented, with emphasis on characterization of structure-property relationships in imidazole-based materials through both experimental and computational studies. To this end, a growing library of systematically varied imidazole compounds has been synthesized using only commercial available starting materials and straightforward reactions. Using this library of compounds, we have sought to understand and develop predictive models for thermophysical properties relating to process design, including: density, viscosity, vapor pressure, pKa and CO2 absorption capacity. Furthermore, we have discovered that imidazoles are stable in the presence of SO2 and can form reversible 1:1 adducts, which can be beneficial as SO2 is typically present at ppm levels alongside CO2 in flue gas from coal-fired power plants.
Offspring ADHD as a Risk Factor for Parental Marital Problems: Controls for Genetic and Environmental Confounds
- Alice C. Schermerhorn, Brian M. D'Onofrio, Wendy S. Slutske, Robert E. Emery, Eric Turkheimer, K. Paige Harden, Andrew C. Heath, Nicholas G. Martin
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- Journal:
- Twin Research and Human Genetics / Volume 15 / Issue 6 / December 2012
- Published online by Cambridge University Press:
- 10 September 2012, pp. 700-713
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Background: Previous studies have found that child attention-deficit/hyperactivity disorder (ADHD) is associated with more parental marital problems. However, the reasons for this association are unclear. The association might be due to genetic or environmental confounds that contribute to both marital problems and ADHD. Method: Data were drawn from the Australian Twin Registry, including 1,296 individual twins, their spouses, and offspring. We studied adult twins who were discordant for offspring ADHD. Using a discordant twin pairs design, we examined the extent to which genetic and environmental confounds, as well as measured parental and offspring characteristics, explain the ADHD–marital problems association. Results: Offspring ADHD predicted parental divorce and marital conflict. The associations were also robust when comparing differentially exposed identical twins to control for unmeasured genetic and environmental factors, when controlling for measured maternal and paternal psychopathology, when restricting the sample based on timing of parental divorce and ADHD onset, and when controlling for other forms of offspring psychopathology. Each of these controls rules out alternative explanations for the association. Conclusion: The results of the current study converge with those of prior research in suggesting that factors directly associated with offspring ADHD increase parental marital problems.
Parental depression and offspring psychopathology: a Children of Twins study
- A. L. Singh, B. M. D'Onofrio, W. S. Slutske, E. Turkheimer, R. E. Emery, K. P. Harden, A. C. Heath, P. A. F. Madden, D. J. Statham, N. G. Martin
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- Psychological Medicine / Volume 41 / Issue 7 / July 2011
- Published online by Cambridge University Press:
- 08 November 2010, pp. 1385-1395
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Background
Associations between parental depression and offspring affective and disruptive disorders are well documented. Few genetically informed studies have explored the processes underlying intergenerational associations.
MethodA semi-structured interview assessing DSM-III-R psychiatric disorders was administered to twins (n=1296) from the Australian Twin Register (ATR), their spouses (n=1046) and offspring (n=2555). We used the Children of Twins (CoT) design to delineate the extent to which intergenerational associations were consistent with a causal influence or due to genetic confounds.
ResultsIn between-family analyses, parental depression was associated significantly with offspring depression [hazard ratio (HR) 1.52, 95% confidence interval (CI) 1.20–1.93] and conduct disorder (CD; HR 2.27, CI 1.31–3.93). Survival analysis indicated that the intergenerational transmission of depression is consistent with a causal (environmental) inference, with a significant intergenerational association in offspring of discordant monozygotic (MZ) twin pairs (HR 1.39, CI 1.00–1.94). Logistic regression analysis suggested that the parental depression–offspring CD association was due to shared genetic liability in the parents and offspring. No intergenerational association was found when comparing the offspring of discordant MZ twins [odds ratio (OR) 1.41, CI 0.63–3.14], but offspring of discordant dizygotic (DZ) twins differed in their rates of CD (OR 2.53, CI 0.95–6.76). All findings remained after controlling for several measured covariates, including history of depression and CD in the twins' spouses.
ConclusionsThe mechanisms underlying associations between parental depression and offspring psychopathology seem to differ depending on the outcome. The results are consistent with a causal environmental role of parental depression in offspring depression whereas common genetic factors account for the association of parental depression and offspring CD.
Bulimia nervosa and major depression: a study of common genetic and environmental factors
- Ellen E. Walters, Michael C. Neale, Lindon J. Eaves, Andrew C. Heath, Ronald C. Kessler, Kenneth S. Kendler
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- Journal:
- Psychological Medicine / Volume 22 / Issue 3 / August 1992
- Published online by Cambridge University Press:
- 09 July 2009, pp. 617-622
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A genetic analysis of the co-occurrence of bulimia and major depression (MD) was performed on 1033 female twin pairs obtained from a population based register. Personal interviews were conducted and clinical diagnoses made according to DSM-III-R criteria.
Additive genes, but not family environment, are found to play an important aetiological role in both bulimia and MD. The genetic liabilities of the two disorders are correlated 0·456. While unique environmental factors account for around half of the variation in liability to both bulimia and MD, these risk factors appear to be unrelated, i.e., each disorder has its own set of unique environmental risk factors. Thus, the genetic liability of bulimia and MD is neither highly specific nor entirely nonspecific. There is some genetic correlation between the two disorders as well as some genetic and environmental risk factors unique to each disorder. Limitations and directions for future research are discussed.
Detection of specific IgM in varicella and herpes zoster by antibody-capture redioimmunoassay
- H. O. Kangro, A. Ward, S. Argent, R. B. Heath, J. E. Cradock-Watson, Margaret K. S. Ridehalgh
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- Journal:
- Epidemiology & Infection / Volume 101 / Issue 1 / August 1988
- Published online by Cambridge University Press:
- 15 May 2009, pp. 187-195
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A simple and sensitive M antibody-capture radioimmunoassay (MACRIA) is described which utilizes crude commercial VZV antigen and a single monoclonal anti-VZV antibody. This was compared to the immunofluorescence (IF) test for IgM antibody and was used to study IgM responses in sera from 261 patients with varicella and 220 patients with herpes zoster.
With MACRIA, IgM antibodies were detected in all patients with varicella. The IgM antibodies appeared shortly after onset of rash, reached peak levels between 1 and 4 weeks after onset and then declined to low or undetectable levels in most, though not all, patients after 3 months. IgM antibodies were also detected in 98·2% of patients with herpes zoster, but the levels of IgM were significantly lower than after varicella and there was wider individual variation both in magnitude and duration of the IgM responses, in some cases only lasting 2–3 weeks.
Comparison between MACRIA and IF showed good agreement in the detection of IgM antibodies following varicella. Discordant results were obtained with 13% of sera. of which 81% were taken either early or late after onset of rash and contained very low IgM levels. In contrast, 62 (28%) of the 220 sera from patients with zoster gave discordant results in the two tests, all except five being MACRIA positive but IF-negative. The largest proportion of discordant results were obtained with sera taken more than 3 months after onset of rash, but 18 (29%) contained high IgM levels and were taken during the period of peak IgM responses. The diagnostic applications of the VZV MACRIA are discussed.
Changes in ascertainment of Hib and its influence on the estimation of disease incidence in the United Kingdom
- S. LADHANI, M. P. SLACK, P. T. HEATH, M. E. RAMSAY
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- Journal:
- Epidemiology & Infection / Volume 135 / Issue 5 / July 2007
- Published online by Cambridge University Press:
- 09 November 2006, pp. 861-867
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Enhanced surveillance for Hib infection, initially covering Wales and five English regions, began in 1990 and in 1995 was extended to the whole of England and Wales. To determine whether changes in the ascertainment of Haemophilus influenzae may have affected estimates of Hib disease incidence, data from January 1990 to December 2003 were analysed. A total of 8887 and 4020 (45%) cases of H. influenzae and Hib respectively were reported. The proportion of isolates that were serotyped increased over time, and therefore reported incidence may have underestimated the true incidence in the early years of the study. Adjusting for this under-ascertainment, the incidence in children aged <5 years declined from a peak of 28·3/100 000 in 1991 to 0·97/100 000 in 1998 and increased to 3·8/100 000 in 2003. Following the implementation of universal vaccination a dramatic decline in the true incidence of invasive Hib disease occurred. The observation of the subsequent resurgence was real but the highest incidence reached was 85% below the corrected incidence in the pre-vaccine era. Continued high-quality surveillance is needed in order to accurately monitor and detect changes in disease incidence.
A twin study of genetic and environmental influences on suicidality in men
- Q. FU, A. C. HEATH, K. K. BUCHOLZ, E. C. NELSON, A. L. GLOWINSKI, J. GOLDBERG, M. J. LYONS, M. T. TSUANG, T. JACOB, M. R. TRUE, S. A. EISEN
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- Journal:
- Psychological Medicine / Volume 32 / Issue 1 / January 2002
- Published online by Cambridge University Press:
- 05 February 2002, pp. 11-24
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Background. Previous studies that have examined genetic influences on suicidal behaviour were confounded by genetic vulnerability for psychiatric risk factors. The present study examines genetic influences on suicidality (i.e. suicidal ideation and/or suicide attempt) after controlling for the inheritance of psychiatric disorders.
Methods. Sociodemographics, combat exposure, lifetime DSM-III-R major depression, bipolar disorder, childhood conduct disorder, adult antisocial personality disorder, panic disorder, post-traumatic stress disorder, drug dependence, alcohol dependence and lifetime suicidal ideation and attempt were assessed in 3372 twin pairs from the Vietnam Era Twin Registry who were assessed in 1987 and 1992. Genetic risk factors for suicidality were examined in a multinomial logistic regression model. Additive genetic, shared environmental and non-shared environmental effects on suicidality were estimated using structural equation modelling, controlling for other risk factors.
Results. The prevalence of suicidal ideation and suicide attempt were 16·1% and 2·4% respectively. In a multinomial regression model, co-twin’s suicidality, being white, unemployment, being other than married, medium combat exposure and psychiatric disorders were significant predictors for suicidal ideation. Co-twin’s suicidality, unemployment, marital disruption, low education attainment and psychiatric disorders (except childhood conduct disorder) were significant predictors for suicide attempt. Model-fitting suggested that suicidal ideation was influenced by additive genetic (36%) and non-shared environmental (64%) effects, while suicide attempt was affected by additive genetic (17%), shared environmental (19%) and non-shared environmental (64%) effects.
Conclusions. There may be a genetic susceptibility specific to both suicidal ideation and suicide attempt in men, which is not explained by the inheritance of common psychiatric disorders.
On the “Specifics” of Specific Reading Disability and Specific Language Impairment
- G. M. McArthur, J. H. Hogben, V. T. Edwards, S. M. Heath, E. D. Mengler
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- Journal:
- The Journal of Child Psychology and Psychiatry and Allied Disciplines / Volume 41 / Issue 7 / October 2000
- Published online by Cambridge University Press:
- 02 November 2000, pp. 869-874
- Print publication:
- October 2000
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The reading and oral language scores of 110 children with a specific reading disability (SRD) and 102 children with a specific language impairment (SLI) indicated that approximately 53% of children with an SRD and children with an SLI could be equally classified as having an SRD or an SLI, 55% of children with an SRD have impaired oral language, and 51% of children with an SLI have a reading disability. Finding that a large percentage of children can be equally classified as SRD or SLI has repercussions for the criteria used to define an SRD, for conceptualising subgroups of learning disability, and for estimates of the incidence of SRD. Further, it highlights the need for future studies to assess both the reading and oral language abilities of SRD and SLI participants to determine how specifically impaired and homogeneous samples really are.
A Study of Psychodynamic Changes in Untreated Neurotic Patients: I. Improvements that are questionable on dynamic criteria
- D. H. Malan, H. A. Bacal, E. S. Heath, F. H. G. Balfour
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- Journal:
- The British Journal of Psychiatry / Volume 114 / Issue 510 / May 1968
- Published online by Cambridge University Press:
- 29 January 2018, pp. 525-551
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- May 1968
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Short Courses of E.C.T. and Simulated E.C.T. in Chronic Schizophrenia
- E. S. Heath, Anne Adams, P. L. G. Wakeling
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- Journal:
- The British Journal of Psychiatry / Volume 110 / Issue 469 / November 1964
- Published online by Cambridge University Press:
- 29 January 2018, pp. 800-807
- Print publication:
- November 1964
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The problem of treating the “back ward” chronic schizophrenic is likely to remain for some years to come, and with it the problem of establishing the genuine effectiveness of particular treatments. Disentangling effective from non-effective therapeutic techniques in “total-push” programmes is particularly complicated. What precisely is responsible for the minimal improvements observed: some subtle change in “ward climate”, the altered medication or the new music therapist? Writers who view mental illness primarily as a breakdown in normal interactional relationships with other persons have stressed the therapeutic importance of certain types of social milieu (e.g. Martin, 1962). Others (e.g. Greenblatt et al., 1955) have suggested that the success of even the physical treatments can be explained in terms of the optimism and enthusiasm with which they are carried out. However, there are few systematic research attempts to disentangle the physiological from the psychological variables.