Showing papers by "Michael Rutter published in 2003"

Using sex differences in psychopathology to study causal mechanisms: unifying issues and research strategies.

Abstract: Background: Although there is an extensive literature, both speculative and empirical, on postulated differences between males and females in their rates of particular types of disorder, very little is known about the mechanisms that underlie these sex differences. The study of mechanisms is important because it may provide clues on aetiological processes. The review seeks to outline what is known, what are the methodological hazards that must be dealt with, and the research strategies that may be employed. Methods: We note the need for representative general samples, and for adequate measurement and significance testing if valid conclusions are to be drawn. We put forward three levels of causes that have to be considered: a genetically determined distal basic starting point; the varied consequences of being male or female; and the proximal risk or protective factors that are more directly implicated in the causal mechanisms that predispose to psychopathology. In delineating these, we argue that three key sets of evidential criteria have to be met: a) that the risk factors differ between males and females; b) that they provide for risk or protection within each sex; and c) that when introduced into a causal model, they eliminate or reduce the sex differences in the disorders being studied. Results: A male excess mainly applies to early onset disorders that involve some kind of neurodevelopmental impairment. A female excess mainly applies to adolescent-onset emotional disorders. No variables have yet met all the necessary criteria but some good leads are available. The possible research strategies that may be employed are reviewed. Conclusions: The systematic investigation of sex differences constitutes an invaluable tool for the study of the causal processes concerned with psychopathology.

Child-parent attachment following early institutional deprivation.

Abstract: Child-parent attachment quality with an adoptive caregiver at age 4 years was examined in a sample of 111 children adopted into the United Kingdom following early severe deprivation in Romania and a comparison group of 52 nondeprived within-United Kingdom adoptees. Findings indicated that, compared with nondeprived adoptees, children who experienced early severe deprivation were less likely to be securely attached and more likely to show atypical patterns of attachment behavior; ordinary forms of insecure attachment were not associated with deprivation. Within the sample of deprived adoptees, there was a dose-response association between duration of deprivation and disturbances in attachment behavior. In addition, a minority of children who experienced severe early deprivation were classified as avoidant, secure, or dependent using conventional classification strategies, despite also exhibiting atypical patterns of attachment behaviors, and this was also more likely among children exposed to prolonged deprivation. The results raise both theoretical and methodological implications for attachment research on very deprived children.

Twins as a natural experiment to study the causes of mild language delay: I: Design; twin-singleton differences in language, and obstetric risks.

Abstract: Background:Twins tend to lag behind singletons in their language development, but the causes were unknown. The possibilities suggested include obstetric complications, twin-specific features, and postnatal differences in family interaction. The present study was designed to pit these alternatives against one another as possible causal influences. Method:The Avon Longitudinal Study of Parents and Children (ALSPAC) was used to identify the 116 twin pairs (of whom 96 participated) and 114 pairs of singletons (of whom 98 participated) whose ages were no more than 30 months apart. The McArthur Communicative Development Inventory was completed at 20 months, and the Pre-School Language Scales (PLS-3), and the McCarthy Scales of Children's Abilities at 36 months. Obstetric and perinatal complications were assessed on the basis of detailed systematic parental reports, together with a systematic coded abstraction of all medical records dealing with pregnancy and the neonatal period. Family background details were assessed from parental reports, and the primary carer's verbal functioning was assessed by the Mill Hill Vocabulary Scale. Congenital anomalies were assessed using the method of Waldrop and Halverson. Results:The language of twins was 1.7 months below that of singletons at 20 months and 3.1 months at 3 years. The verbal cognitive score of twins was about half a standard deviation lower than that of singletons. The twin–singleton differences in language level were found to be unassociated with obstetric/perinatal features as assessed from both parental reports and medical records, to birthweight or gestation, to birthweight discrepancy within the twin pair, or to congenital anomalies. Conclusions:It is concluded that obstetric/perinatal features do not account for the slower language development in twins as compared with singletons, within a sample born after at least 33 weeks gestation.

Twins as a natural experiment to study the causes of mild language delay: II: Family interaction risk factors.

Abstract: Background: Twins tend to lag behind singletons in their language development, but the causes were unknown. Method: Ninety-six twin pairs from the Avon Longitudinal Study of Parents and Children (ALSPAC), for whom birth was after at least 33 weeks of gestation, were compared with 98 pairs of singletons, no more than 30 months apart in age. Parental qualities and family interaction were assessed through standardised questionnaires and interviews and both structured and unstructured observations in the home at 20 months and 36 months. The possible causal role of postnatal family influences was assessed through five criteria: i) the feature had to differ between twins and singletons; ii) individual differences in that feature had to relate to individual differences in language level within the sample of singletons and of twins; iii) the feature as measured at 20 months had to predict language as assessed at 36 months; iv) that had to apply after controlling for language level at 20 months; and v) introduction of the predictive feature into an overall model had to obliterate the twin‐singleton difference in language level. Results: Patterns of parent‐child interaction and communication met these five criteria. The maternal factors all concerned aspects of interaction that were broadly concerned with communication: encouraging the child to speak, providing elaborating comments, engaging in reading to the child and talking about the story and its illustrations. The HOME inventory findings provided similar findings with respect to responsiveness, involvement and level of experiences involved. Family features that might have been influential, but which were not, included parental depression, breastfeeding, family size, and style of sibling interaction. Conclusion: Patterns of parent‐child interaction and communication within the normal range have environmentally mediated effects on language and account for twin‐singleton differences in language developmently. The results indicate the value of a natural experiment in testing competing causal hypotheses, and show the role of environmental factors as influences on language variations within the normal range, for both twins and singletons. Keywords: Twins, singletons, parent‐child interaction, parent‐child communication, language delay, parental depression, breastfeeding, family size, sibling interaction, natural experiment. Twins provide a different parenting task from that presented by singletons (Rutter & Redshaw, 1991). Moreover, the family constellation, with two young children at the same developmental stage, also provides a different language environment that could have implications for the communicative development of the children. The burden on parents during the infancy period is clearly greater ‐ not only because there are two babies to look after, but also because their feeding and sleeping patterns are quite likely not to coincide. It is not surprising, therefore, that the mothers of twins have been found to have higher rates of depression than the mothers of sin

Genetic and environmental risk factors in adolescent substance use.

Abstract: Background: The present study was undertaken with the goal of understanding the causes of association between substance use and both conduct disturbance (CD) and depression in adolescent boys and girls. Method: Multivariate genetic structural equation models were fitted to multi-informant, multi-wave, longitudinal data collected in extensive home interviews with parents and children with respect to 307 MZ male, 392 MZ female, 185 DZ male, and 187 DZ female, same-sex twin pairs aged 12–17 years from the Virginia Twin Study of Adolescent Behavioral Development (VTSABD). Results: Although conduct disturbance and depression were moderately associated with substance use, the pattern of genetic and environmental risk differed for males and females and across the two disorders. Genetic factors were predominant in girls’ substance use whereas boys’ use was mediated primarily by shared environmental factors reflecting family dysfunction and deviant peers. The patterns of correlations across the two waves of the study were consistent with conduct disturbance leading to substance use in both males and females, but depression leading to smoking, drug use and, to a lesser extent, alcohol use in girls. Conclusions: The comorbidity between substance use and depression, and between substance use and conduct disturbance in childhood/adolescence, probably reflects rather different mediating mechanisms – as well as a different time frame, with conduct disturbance preceding substance use but depression following it. In both, the co-occurrence partially reflected a shared liability but, in girls, genetic influences played an important role in the comorbidity involving depression, whereas in both sexes (but especially in boys) environmental factors played a substantial role. The extent to which these differences reflect genuine differences in the causal mechanisms underlying substance use and CD/depression in boys and girls revealed in the present analysis awaits replication from studies of other general population samples.

Commentary: causal processes leading to antisocial behavior.

Abstract: Conceptual, and empirical, questions are raised regarding the notion that physical aggression is the main individual risk factor for antisocial behavior, that language impairment also constitutes a risk factor, the meaning of the male preponderance for antisocial behavior, the findings on environmentally mediated risk; the role of biosocial interplay; social context effects; the construct of antisocial behavior, developmental trends; processing of experiences; and transactional effects. The main blocks to using research to develop policy are the lack of evidence on (a) the mediators of the causal processes, (b) what is needed to bring about change, (c) ways to ensure that individuals who need interventions actually receive them, and (d) differences in levels of antisocial behavior.

Categories, dimensions, and the mental health of children and adolescents.

Abstract: Concepts of mental disorder, and of the causal processes leading to disorder, have undergone radical changes over recent decades. Genetic findings, for example, have shown that (1) many conditions develop on the basis of a dimensional genetic liability; (2) the boundaries of some conditions extend much more broadly than indicated by the traditional diagnostic categories; and (3) there is substantial overlap between conditions previously thought to be distinctively different. On the other hand, genetic findings have also provided support for the validity of some diagnostic distinctions. Early molecular genetic research was conceptualized on the basis of the expectation that there would be disease-specific genes “for” schizophrenia, bipolar disorder, and the like. It has become apparent that, at best, this constitutes a misleading oversimplification. Almost all mental disorders (in childhood and adult life) have a multifactorial origin, and the genes are likely to operate through a range of direct and indirect routes. Gene-environment correlations and interactions are important, and there is a biological substrate for individual differences in responses to psychosocial stress and adversity, as well as for the effects of such stress and adversity on the organism. The empirical basis for these changes in concepts is reviewed, and the implications for clinical science and practice are considered.

Health Problems in Children Adopted from Romania: Association with Duration of Deprivation and Behavioural Problems

Abstract: This paper by Celia Beckett, Jenny Castle, Christine Groothues, Thomas G O'Connor, Michael Rutter and the English and Romanian Adoptees (ERA) study team* examines the pattern of health problems as reported by parents in a group of children adopted from Romania and relates these findings to outcomes at age six. The study is based on a representative sample of 165 children, 144 of whom had experienced institutional deprivation, and a UK adoptee group of 52 non-deprived UK adoptees. At the time of UK entry, over half of the children adopted from Romania had marked health problems. The majority had suffered severe malnutrition and there was a high incidence of respiratory, skin and gastro-intestinal infections; 13 per cent had antibodies to hepatitis B. At age six, 17 per cent of the children had conductive hearing loss, 12 per cent had continuing strabismus and 35 per cent skin problems; half of those infected with hepatitis B were still surface antigen positive. Inattention/overactivity at age six was found...

Brief measure of expressed emotion: internal consistency and stability over time.

Abstract: The study examined three methodological aspects of expressed emotion (EE) as assessed in the course of PACE (Psychosocial Assessment of Childhood Experiences) interviews with a parent. In a sample of 87 children, aged 6–13 years, enrolled in a prospective study examining the role of stress on the course of asthma, EE was assessed at three time points, 9 months apart. A high degree of agreement was found among the three concurrent measures of negative and positive EE (kappas from 0.74 to 0.97, and from 0.45 to 0.88, respectively; p ≤ 0.0001 in all instances). The temporal stability of all measures was lower, although statistically significant in all but 2 instances (kappas from 0.19 to 0.59, and from 0.11 to 0.39, respectively). The temporal stability across measures, as well as across interviewers and over time, was broadly similar (kappas from 0.21 to 0.56 for negative EE, and from 0.09 to 0.38 for positive EE, with all but three of the 36 statistically significant). The findings provide support for the underlying assumptions of the PACE-EE and show the utility of measures based on just very brief periods of non-directive interviewing, making them practical in a wide range of studies with EE just one of a larger set of measures. Copyright © 2003 Whurr Publishers Ltd.

Introduction: autism--the challenges ahead.

Abstract: There have been many important advances in research into the nature of autism and, as a result, our concepts of autism have undergone a radical change (Rutter 1999). At one time, the prevailing view was that autism was an unusually early variety of schizophrenia that had been caused, in large part, by so-called refrigerator parenting. It became clear that that was a wholly mistaken concept and that, instead, autism constitutes a neurodevelopmental disorder with a rather distinctive pattern of cognitive de¢cits, and that it is strongly genetically in£uenced. Nevertheless, we are a longway fromunderstanding the basic pathophysiology, and numerous puzzles and paradoxes remain. The aim of this symposium is to grapple with these issues, tackling the challenges from a range of di¡erent perspectives in the hope that a coming together of minds, and of di¡erent research strategies, may point the way ahead. My task is to set the scene by outlining some of these challenges in order to provoke us all to abandon the safety of our own research territory, and of the ¢ndings that are well established, in order to focus on the di⁄culties that are inherent in our favoured theories. We need to begin with implications of the huge rise in diagnosed autism (Baird et al 2000, Chakrabarti & Fombonne 2001, Fombonne 1999). To a substantial extent, this rise is a consequence of a major broadening of the concept of autism together with better ascertainment. However, is that all? When like is compared with like, has there been a real rise in the rate of autism? If that should prove to be the case, what is the environmental factor that has brought this about (the rise is unlikely to have been genetically determined)? There have been claims that the rise is due to the use of the combined measles/mumps/rubella (MMR) vaccine but that does not seem very likely. The rise began before the introduction of MMR and it continued to rise, without any plateauing, after MMR was used with the vast majority of the population (Dales et al 2001, Farrington et al 2001, Taylor et al 1999). But, if that is not the cause, what is?