Showing papers by "Michael Rutter published in 1997"

Genetics and Developmental Psychopathology: 2. The Main Effects of Genes and Environment on Behavioral Problems in the Virginia Twin Study of Adolescent Behavioral Development

Abstract: Little is known about the contribution of genetic and environmental factors to risk for juvenile psychopathology. The Virginia Twin Study of Adolescent Behavioral Development allows these contributions to be estimated. A population-based, unselected sample of 1412 Caucasian twin pairs aged 8-16 years was ascertained through Virginia schools. Assessment of the children involved semi-structured face-to-face interviews with both twins and both parents using the Child and Adolescent Psychiatric Assessment (CAPA). Self-report questionnaires were also completed by parents, children, and teachers. Measures assessed DSM-III-R symptoms of Attention Deficit Hyperactivity Disorder (ADHD). Conduct Disorder, Oppositional Defiant Disorder, Overanxious Disorder, Separation Anxiety, and Depressive Disorder. Factorially derived questionnaire scales were also extracted. Scores were normalized and standardized by age and sex. Maximum likelihood methods were used to estimate contributions of additive and nonadditive genetic effects, the shared and unique environment, and sibling imitation or contrast effects. Estimates were tested for heterogeneity over sexes. Generally, monozygotic (MZ) twins correlated more highly than dizygotic (DZ) twins, parental ratings more than child ratings, and questionnaire scales more highly than interviews. DZ correlations were very low for measures of ADHD and DZ variances were greater than MZ variances for these variables. Correlations sometimes differed between sexes but those for boy-girl pairs were usually similar to those for like-sex pairs. Most of the measures showed small to moderate additive genetic effects and moderate to large effects of the unique individual environment. Measures of ADHD and related constructs showed marked sibling contrast effects. Some measures of oppositional behavior and conduct disorder showed shared environmental effects. There were marked sex differences in the genetic contribution to separation anxiety, otherwise similar genetic effects appear to be expressed in boys and girls. Effects of rater biases on the genetic analysis are considered. The study supports a widespread influence of genetic factors on risk to adolescent psychopathology and suggests that the contribution of different types of social influence may vary consistently across domains of measurement.

Integrating nature and nurture: Implications of person-environment correlations and interactions for developmental psychopathology

Abstract: The developmental interplay between nature and nurture is discussed, with particular reference to implications for research in developmental psychopathology. The general principles include individual differences in reactivity to the environment, two-way interplay between intraindividual biology and environmental influences, and the need to consider broader social contextual features. Individuals actively process their experiences; they also act on their environment to shape and select their experiences, and individual characteristics change over time. Key findings on genetic effects include their ubiquitous influence, the multifactorial origin of most psychopathology, the involvement of several genes in most mental disorders, some genetic effects operate through dimensional risk features rather than directly on disorder, some genetic effects are dependent on gene-environment correlations and interactions, and genetic effects increase with age. Key findings on environmental effects include their ubiquitous influence, the genetic mediation of some supposed environmental effects, the importance of passive gene-environment correlations, the paucity of evidence regarding environmental effects on lifetime liability to psychopathology, the lack of understanding of environmental effects on the organism, and the importance of nonshared environmental effects. Research strategies to investigate environmental risk mediation include the range of genetically sensitive designs, migration studies, secular trend investigations, studies of nonfamilial environments, and examination of intraindividual change in relation to measured environmental alterations. Proximal processes involved in person-environment interplay are discussed in relation to person-environment interactions and evocative and active person-environment correlations.

Diagnosing Autism: Analyses of Data from the Autism Diagnostic Interview

Abstract: Results from ROC curves of items from two scales, the Autism Diagnostic Interview (ADI) and Autism Diagnostic Interview-Revised (ADI-R), operationalizing DSM-IV criteria for autism are presented for 319 autistic and 113 other subjects from 8 international autism centers. Analyses indicate that multiple items were necessary to attain adequate sensitivity and specificity if samples with varying levels of language were considered separately. Although considering only current behavior was generally sufficient when a combination cutoff and additive model was employed, predictive power was highest when history was taken into account. A single set of criteria, as operationalized by individually structured questions in the ADI/ADI-R, was effective in differentiating autism from mental handicap and language impairment in subjects with a range of chronological ages and developmental levels.

The Virginia Twin Study of Adolescent Behavioral Development: Influences of Age, Sex, and Impairment on Rates of Disorder

Abstract: Background: The Virginia Twin Study of Adolescent Behavioral Development is a cohort-longitudinal epidemiological study that uses the genetic twin design to study the development and maintenance of child psychiatric disorders. We determined the rates of DSM-III-R disorders, disorders with impairment, and age, sex, and co-morbidity effects. Methods: Families of 2762 white twins aged 8 to 16 years participated. Twins and their parents were asked systematically about risk factors and current psychiatric symptoms by means of investigator-based psychiatric interviews and questionnaires. The DSM-III-R diagnoses were made for major depressive disorder, separation anxiety, overanxious disorder, simple phobia, social phobia, agoraphobia, oppositional defiant disorder, conduct disorder, and attention deficit hyperactivity disorder. Results: The 3-month point prevalence for any DSM-III-R disorders was 413 per 1000, and that for disorders with associated impairment was 142 per 1000. Emotionnal disorders with impairment occurred in 89 per 1000, with girls being more commonly affected; behavioral disorders had a prevalence of 71 per 1000, with boys being more frequently affected. The proportion with disorder who also had functional impairment varied across disorders; anxiety and phobic disorders were particularly likely not to be accompanied by impairment. Rates of emotional and behavioral disorders increased over the age range. There was extensive comorbidity among disorders. Conclusions: The prevalence rates and patterns of findings from this study of twins are consistent with those of other epidemiological studies, supporting previous findings of few differences in rates of psychiatric disorder between twins and singletons. The importance of including measures of functional impairment is evident by its effect on rates of disorder and patterns of comorbidity.

Retrospective reporting of childhood adversity: issues in assessing long-term recall.

Abstract: Much evidence for associations between adverse experiences in childhood and personality disorder in adult life comes from retrospective accounts. This raises important questions over the reliability and validity of long-term recall. The strengths and limitations of different methods for assessing the accuracy and stability of retrospective reports are discussed. Evidence from cognitive psychology on memory and memory processes, and on the phenomenon of infantile amnesia, provides important background for assessing issues more specific to recall in studies of risk for psychopathology. Here, topics of particular concern include: memory for traumatic early experience; the effects of mood state and symptomatology on recall; recovered or false memories; and the implications of mental representations of early experience for understanding psychopathology. Current evidence suggests that while adequately reliable accounts of many early experiences can be gained using appropriate techniques, further methodological studies are needed, and investigations using retrospective methods would be wise to include corroborative evidence whenever feasible.

A Family Study of Autism: Cognitive Patterns and Levels in Parents and Siblings

Abstract: First-degree relatives of 99 autism probands and of 36 Down's syndrome controls were assessed with standardised tests of intellectual functioning, reading, and spelling. Higher mean verbal IQ scores, and discrepancies in favour of verbal scores, were characteristic of autism relatives. No consistent differences were found on performance scales, reading, and spelling tests. Among autism relatives, siblings affected with the broad phenotype of autism had significantly lower IQ scores and poorer reading and spelling performances than unaffected siblings. However, the small size of the cognitive difference and the lack of a distinctive cognitive profile indicates that standardised cognitive measures used in this study are unlikely to improve the operationalised definition of the broad phenotype of autism. The slightly superior verbal performance of relatives in the autism group might represent some form of heterozygote advantage.

Obstetric complications in autism: consequences or causes of the condition?

Abstract: Objective To determine whether and why obstetric complications are associated with autism. Method Obstetric histories, obtained at maternal interview and coded as an optimality score (OS), were compared in two groups: 78 families containing an autistic proband ( ICD-10 criteria) and 27 families containing a Down syndrome (DS) proband. The OS was examined in relation to offspring diagnosis, proband characteristics, and familial loading for autism and its phenotypic variants. Results Autistic and DS probands had a significantly elevated OS compared with unaffected siblings, regardless of birth order position. The elevation was mainly due to an increase in mild as opposed to severe obstetric adversities. In autistic probands, the OS was best predicted by familial loading for autism and its phenotypic variants, but in the absence of this measure by the number of autistic symptoms. Among siblings of autistic probands affected with autism or its variants, the OS was best predicted by the probands' OS, and in its absence, by the measure of familial loading. In DS probands and siblings the OS was associated with increased maternal age, although this did not account for the OS elevation in DS probands. Conclusions Rather than playing any principal etiological role, the obstetric adversities associated with autism either represent an epiphenomenon of the condition of derive from some shared risk factor(s).

Opportunities for psychiatry from genetic findings.

Abstract: BACKGROUND The opportunities for psychiatry deriving from available or likely genetic advances are reviewed. METHOD Clinical implications are considered in the context of both the misconceptions and benefits associated with relevant genetic findings. RESULTS Misconceptions include that: heritability estimates have a 'true' fixed value; a high heritability means that environmental interventions will be ineffective; a high heritability within groups means that differences between groups will also be due to genes; genetic effects are determinative; 'genetic' means single abnormal genes; genes associated with disease must be bad and justify eugenic measures; gene therapy will be widely applicable; and genetic screening of the general population will be useful. The benefits include demonstrations that: both genes and environment have an ubiquitous influence; some prevailing diagnostic assumptions are mistaken; genes influence development; the effects of nature and nurture are not separate; and environmental effects tend to be person-specific. The potential value of molecular genetics lies in elucidation of causal processes as they apply to both brain systems and nature-nurture interplay; improving diagnosis and genetic counselling; and the development of improved pharmacological interventions. CONCLUSION Advances in genetics will make a major impact on clinical psychiatry, and should bring practical benefits for both prevention and treatment.

Genetics and Developmental Psychopathology: 1. Phenotypic Assessment in the Virginia Twin Study of Adolescent Behavioral Development

Abstract: We introduce an overlapping cohort sequential longitudinal study of behavioral development and psychopathology in a representative sample of 1412 pairs of twins aged 8 through 16 years. Multiple phenotypic assessments involve a full psychiatric interview with each child and each parent, and supplementary parental, teacher, and child interview material and questionnaires. For the first wave of assessments, the numbers of reported DSM-III-R symptoms of Major Depressive Disorder (MDD), Separation Anxiety Disorder (SAD), Overanxious Disorder (OAD), Oppositional Defiant Disorder (ODD), Conduct Disorder (CD), and Attention Deficit Hyperactivity Disorder (ADHD), assessed through interviews, confirm patterns of age and sex trends found in other epidemiological samples, but underscore their dependence on whether the child or the parent is the informant. Correlations across domains for symptoms reported by the same informant are often as large as correlations across informants for the same domain of symptoms. Factor analyses of these symptom counts, taking account of informant view and unreliability of assessment, show the high degree of correlation between SAD and OAD, between MDD and OAD, and between CD and ODD. ADHD symptoms are relatively independent of the other domains, but show moderate correlations with CD, ODD, and MDD. Factorially derived dimensional questionnaire scales, based on child, parental, and teacher reports, show patterns of relationship to symptom counts consistent with both convergent and discriminant validity as indices of liability to clinical symptoms. Across informants, questionnaire scales provide as good a prediction of symptoms as do clinical interviews. Multitrait-multimethod confirmatory factor analysis reveals the patterns of relationship between symptoms of psychiatric disorder in children taking due account of informant and unique sources of variance. Gender differences are consistent within the correlated clusters of ODD/CD and MDD/SAD/OAD, although there are disorder-specific age trends. There are large informant-specific influences on the reporting of symptoms in clinical interviews. Dimensional questionnaire scales provide a useful source of additional information. In subsequent analyses of genetic and environmental etiology of childhood psychopathology we must expect that results may differ by informant and method of assessment. Multivariate and developmental analyses that explore the sources of these differences will shed new light on the relationship between genetic and environmentally influenced vulnerability and the manifestation of psychopathology in specific circumstances.

Comorbidity: concepts, claims and choices

Abstract: The presence of comorbidity may distort research findings but, if properly dealt with, it also provides important research opportunities to test hypotheses about causal mechanisms. Seven possible sources of artefactual comorbidity are noted. Five key alternative bases for apparent comorbidity are discussed, using medical examples to illustrate the different processes that they may represent. They are that the apparent comorbidity: (1) represents two manifestations of the same disorder; (2) reflects two stages of the same underlying condition; (3) arises from the same or correlated risk factors; (4) represents a nosologically distinct condition; and (5) is due to one condition predisposing to the other. All possibilities, however, have to start with demonstration of the distinctiveness of the two syndromes involved in the comorbidity. Such evidence may be provided by differences in: (1) pathophysiology or pathopsychology; (2) correlates likely to reflect aspects of causal processes; or (3) treatment responses and adult outcome. Copyright © 1997 Whurr Publishers Ltd.

Psychosocial Adversities in Childhood and Adult Psychopathology

Abstract: Numerous studies have reported statistical associations between adverse childhood experiences and psychopathology in adult life A range of conceptual and methodological issues needs to be borne in mind in interpreting these findings Methodological issues include implications of base rates of postulated risk and outcome measures, and the possibility of third variable effects Conceptually, further evidence is needed on the aspects of early experience most likely to contribute to risk (acute vs chronic stressors: actively negative vs lack of positive experiences; and the implications of cognitive processing of events); the specificity of effects; possible mechanisms involved in mediating effects in childhood, and approaches to testing them: and factors involved in persistence into adult life There are good reasons to assume that adverse early experience plays a contributory role in the genesis of personality disorder However, at this stage, evidence is still limited on how this comes about

Genetic and environmental influences on child reports of manifest anxiety and symptoms of separation anxiety and overanxious disorders: a community-based twin study.

Abstract: Genetic and environmental influences in the determination of individual differences in self-reported symptoms of separation anxiety (SAD), overanxious disorder (OAD), and manifest anxiety (MANX) were evaluated in children and adolescents for three age groups (8-10, 11-13, and 14-16). Symptom counts for SAD and OAD were assessed for 1,412 twin pairs using the children's version of the Child and Adolescent Psychiatric Assessment, and MANX scores were based on child report from the Revised Children's Manifest Anxiety Scales. Despite significant age and gender differences in thresholds of liability for child reports of symptoms of SAD and OAD, additive genetic and environmental effects could be set equal across age and gender for these variables. For MANX, however, the best-fitting model was a common effects sex-limitation model with estimates of heritability varying dependent upon age and gender. Parameter estimates from the ACE models of OAD and SAD showed that additive genetic variation was a necessary component in the explanation of individual differences in child-reported symptoms of OAD (h2 = .37) across gender, but does not appear to be a major contributor to the explanation of individual differences in symptoms of SAD reported by children. Shared environmental effects (c2 = .40) were found to play a moderate role for SAD but could be dropped from the model for OAD and from all of the age groups for MANX, although the parameter approached significance among 11 yr to 13-year-old males.

Mental retardation : genetic findings, clinical implications and research agenda

Abstract: The most important genetic advances in the field of mental retardation include the discovery of the novel genetic mechanism responsible for the Fragile X syndrome, and the imprinting involved in the Prader-Willi and Angelman syndromes, but there have also been advances in our understanding of the pathogenesis of Down syndrome and phenylketonuria. Genetic defects (both single gene Mendelizing disorders and cytogenetic abnormalities) are involved in a substantial proportion of cases of mild as well as severe mental retardation, indicating that the previous equating of severe mental retardation with pathology, and of mild retardation with normal variation, is a misleading over-simplication. Within the group in which no pathological cause can be detected, behaviour genetic studies indicate that genetic influences are important, but that their interplay with environmental factors, which are also important, is at present poorly understood. Research into the joint action of genetic and environmental influences in this group will be an important research area in the future.

Child psychiatric disorder. Measures, causal mechanisms, and interventions

Abstract: DURING RECENT decades there has been a spectacular burgeoning of research into child psychiatric disorders. The results have changed clinical practice in child psychiatry1and have done much to aid understanding of the childhood roots of some adult psychiatric disorders.2The set of 12 articles in this issue of theArchivesillustrate well the accomplishments and the serious challenges that remain. They cover a wide territory, but their key messages may be summarized under the headings of measurement, causal mechanisms, and therapeutic interventions. MEASUREMENT Psychiatric research continues to be troubled by difficulties in measurement.3At one time, many investigators thought that the use of standardized interviews and operationalized criteria for diagnosis would solve the problems, but it is evident that they have not. The study by Boyle et al4is helpful in focusing on the relative merits and demerits of structured respondent-based interviews and checklists. They conclude that there is

Developmental pathways in depression : multiple meanings, antecedents, andendpoints

Abstract: This article presents an overview of work conducted at the Institute of Psychiatry over the past 30 years on childhood depression. The work began with the basic question of definition and measurement. Epidemiological studies showed that depressive symptoms were quite common in children and were a good, if nonspecific, indicator of psychological disturbance. Further work in both epidemiological and clinical samples provided some evidence for the validity of a depressive syndrome . However, this work also showed that these depressive syndromes represented a heterogeneous group of phenomena. The validity of major depressive disorder in children was therefore tested further in longitudinal and family-genetic studies. These studies supported the validity of the concept but confirmed that there was heterogeneity in respect to both developmental stage at the time of onset and comorbidity with conduct disorder. We concluded that there are probably several different kinds of depressive syndromes in children. Some are strongly linked with depressive disorders in adulthood, but others are probably better conceptualized as part of another psychopathological problem altogether.

Implications of Genetic Research for Child Psychiatry

Abstract: Objective:To review implications of genetic research in child psychiatry.Method:Key advances in quantitative and molecular genetics are noted and findings are summarized with respect to autism, att...

Individual Differences and Levels of Antisocial Behavior

Abstract: In considering the interplay between biological and psychosocial processes in the causation of antisocial behavior, the usual approach has been to focus on the causal mechanisms involved in the determination of individual differences. It is important to recognize, however, that that is by no means the only causal question of importance. Policy makers tend to be more concerned with the prevention of the disorders causing social disability than with whether the disorder is shown by this individual or that one. Scientists, too, have needed to study the causal factors involved in either changes in level over time or differences between groups such as those based on gender, age, or country of residence or of origin (Rutter & Smith, 1995). Criminologists sometimes assume that differences in level apply only to aggregated data but, of course, that is not so. Thus, the reduction in level of crime during early adult life applies to individuals as well as to groups. But the differences among individuals in liability to antisocial behaviour provides quite different information. The individual differences concern population variance whereas levels concern overall rates or frequencies.