Institutional care: risk from family background or pattern of rearing?

Previous research has shown that children receiving substitute parental care tend to have high rates of emotional/behavioural disturbance, but uncertainty remains on the extent to which this derives from genetic risk, adverse experiences before receiving substitute care, or from risks associated with substitute care experiences. In order to examine the effects of institutional rearing (as a specific form of substitute care), two groups of primary school children reared in substitute care from before the age of 12 months were compared: 19 children in residential group (institutional) care and 19 in continuous stable foster family care (matched for age and gender). The two groups were similar in coming from biological families with high rates of psychopathology and social malfunctioning, but differed with respect to pattern of rearing. Both groups were compared with classroom controls, using teacher questionnaires, systematic classroom observations, and standardised cognitive testing. Parental questionnaires were also obtained for the two substitute care groups. As found previously, the combined substitute care groups differed from controls in showing a high level of hyperactivity/inattention. The observational measures showed a similar effect, indicating that the elevated rate was not attributable to rater bias. The teacher questionnaire and observational measures showed, however, that the increased level of hyperactivity/ inattention was substantially higher in the institutional group than the foster family group. Parental questionnaire ratings showed the same contrast between the groups, except that the main difference was on unsociability and emotional disturbance rather than hyperactivity/ inattention. It is concluded that, against a background of genetic and early environmental risk, institutional rearing predisposes to a pattern of hyperactivity/inattention.

An evaluation of different approaches for behavior genetic analyses with psychiatric symptom scores

We used a simulation study to evaluate six approaches for behavior genetic analyses of psychiatric symptom scores. For the selection of the correct model, the best results were obtained with approaches using transformed scores in combination with a procedure involving p-values. With normalizing transformations, the chi 2 test statistic gave a reasonable impression of the overall fit of the model but was less accurate when used as a difference test. The asymptotic distribution free estimation methods yielded chi 2s that were much too large. All data analysis techniques yielded substantially biased parameter estimates. The most biased results were obtained with normalizing transformations. The least biased results were obtained with tobit correlations, but because of its large standard errors the most precise estimates were obtained with polychoric correlations and optimal scale scores. An empirical study showed that a recognition of the role of methodological factors was helpful to understand part of the differences between assessment instruments, raters, and data analysis techniques that were found in the real data.

Autism screening questionnaire: diagnostic validity

BACKGROUND

Good interview and diagnostic measures for autism and other pervasive developmental disorders (PDDs) are available but there is a lack of a good screening questionnaire.

AIMS

To develop and test a screening questionnaire based on items in the best available diagnostic interview--the Autism Diagnostic Interview--Revised (ADI-R).

METHOD

A 40-item scale, the Autism Screening Questionnaire (ASQ), was developed and tested on a sample of 160 individuals with PDD and 40 with non-PDD diagnoses.

RESULTS

The ASQ has good discriminative validity with respect to the separation of PDD from non-PDD diagnoses at all IQ levels, with a cut-off of 15 proving most effective. The differentiation between autism and other varieties of PDD was weaker.

CONCLUSIONS

The ASQ is an effective screening questionnaire for PDD.

Maternal and fetal cardiovascular effects of transdermal glyceryl trinitrate and intravenous ritodrine

OBJECTIVE

To determine the maternal and fetal cardiovascular effects of transdermal glyceryl trinitrate compared with ritodrine for acute tocolysis.

METHODS

Sixty women in preterm labor were enrolled in this study that was part of a multicenter study of glyceryl trinitrate. Once randomized, the women received transdermal glyceryl trinitrate or intravenous ritodrine for acute tocolysis. Measurements of maternal pulse, blood pressure (BP), and fetal heart rate (FHR) were recorded for up to 24 hours and compared over the treatment course.

RESULTS

Changes from baseline in mean maternal heart rate, FHR, and maternal BP (mean arterial pressure [MAP]) were compared between the glyceryl trinitrate and ritodrine groups over the entire treatment course. The mean change from baseline in maternal heart rate was 21.1 beats per minute less (95% confidence interval [CI] 15.7, 26.5, P < .001), and the mean maternal heart rate was 21.8 beats per minute lower (95% CI 16.9, 26.7, P < .001) in the glyceryl trinitrate group. The mean change in FHR was 9.2 beats per minute less (95% CI 3.8, 14.6, P = .001) and the mean FHR significantly lower (6.9 beats per minute, 95% CI 1.9, 11.9, P = .008) during glyceryl trinitrate treatment. Ritodrine had a significantly hypotensive effect on MAP (95% CI -4.3, 0.0, P = .03). Mean arterial pressure was not significantly different over the treatment course.

CONCLUSION

At doses required for acute tocolysis, transdermal glyceryl trinitrate had minimal effects on maternal pulse, BP, and FHR, and significantly fewer adverse cardiovascular effects than intravenous ritodrine. Thus, transdermal glyceryl trinitrate might be a safer treatment for women in preterm labor.

Validity of the Malaise Inventory in general population samples

BACKGROUND

The Malaise Inventory is a commonly used self-completion scale for assessing psychiatric morbidity. There is some evidence that it may represent two separate psychological and somatic subscales rather than a single underlying factor of distress. This paper provides further information on the factor structure of the Inventory and on the reliability and validity of the total scale and two sub-scales.

METHODS

Two general population samples completed the full Inventory: over 11,000 subjects from the National Child Development Study at ages 23 and 33, and 544 mothers of adolescents included in the Isle of Wight epidemiological surveys.

RESULTS

The internal consistency of the full 24-item scale and the 15-item psychological subscale were found to be acceptable, but the eight-item somatic sub-scale was less reliable. Factor analysis of all 24 items identified a first main general factor and a second more purely psychological factor. Receiver operating characteristic (ROC) analysis indicated that the validity of the scale held for men and women separately and for different socio-economic groups, by reference to external criteria covering current or recent psychiatric morbidity and service use, and that the psychological sub-scale had no greater validity than the full scale.

CONCLUSIONS

This study did not support the separate scoring of a somatic sub-scale of the Malaise Inventory. Use of the 15-item psychological sub-scale can be justified on the grounds of reduced time and cost for completion, with little loss of reliability or validity, but this approach would not significantly enhance the properties of the Inventory by comparison with the full 24-item scale. Inclusion of somatic items may be more problematic when the full scale is used to compare particular sub-populations with different propensities for physical morbidity, such as different age groups, and in these circumstances it would be a sensible precaution to utilise the 15-item psychological sub-scale.

Tobacco, alcohol and drug use in eight- to sixteen-year-old twins: the Virginia Twin Study of Adolescent Behavioral Development

OBJECTIVE

This study reports prevalences of lifetime and current alcohol, tobacco and drug use in adolescents; examines associations between substance use and a number of putative risk factors; and estimates the contribution of genetic, shared and unique environmental influences on substance use.

METHOD

Substance use data were collected using the Child and Adolescent Psychiatric Assessment on a population sample of 1,412 male and female monozygotic and dizygotic twin pairs, aged 8 through 16, from the Virginia Twin Study of Adolescent Behavioral Development.

RESULTS

Heritabilities were estimated to be 84% and 82% for liability to lifetime and current tobacco use, respectively. For alcohol use the role of genes and environment varied according to the context of reporting. Liability to lifetime alcohol use was estimated to be under environmental control, with 71% of the variation shared by members of a twin pair and 29% unique to individual twins. Lifetime alcohol use without the permission of a parent or guardian and current use of alcohol were predominantly explained by genetic factors (h2 = 72% and 74%). The role of genetic factors increased and that of unique environmental factors decreased with increasing severity of alcohol use. Lifetime use of any drug showed a heritability of 45%, with the shared environment accounting for 47% of the variation. Shared environmental factors explained most of the variation in marijuana use.

CONCLUSIONS

Genetic factors explained a significant proportion of the variation in the use of tobacco, alcohol and other drugs. Shared environmental factors contributed significantly to lifetime alcohol use and other drug use.

Nurse versus technician: the dilemma of intensive care nursing

A definition of technology and technician is offered, relating this to nursing in the intensive care unit. It is evident that technicians are focused upon the goal of providing care to the machinery. Intensive care nurses possess attributes of the technician, but also take into account the wider issues surrounding the patient. A conclusion that technology is a means to aid the nurse during his/her nursing practice is drawn.

Mild mental retardation: psychosocial functioning in adulthood

BACKGROUND

Evidence on the adult adaptation of individuals with mild mental retardation (MMR) is sparse, and knowledge of the factors associated with more and less successful functioning in MMR samples yet more limited.

METHOD

Prospective data from the National Child Development Study were used to examine social circumstances and psychosocial functioning in adulthood in individuals with MMR and in a non-retarded comparison group.

RESULTS

For many individuals with MMR, living circumstances and social conditions in adulthood were poor and potential stressors high. Self-reports of psychological distress in adulthood were markedly elevated, but relative rates of psychiatric service use fell between childhood and adulthood, as reflected in attributable risks. Childhood family and social disadvantage accounted for some 20-30% of variations between MMR and non-retarded samples on a range of adult outcomes. Early social adversity also played a significant role in contributing to variations in functioning within the MMR sample.

CONCLUSIONS

MMR appears to be associated with substantial continuing impairment for many individuals.

The influence of genetic factors and life stress on depression among adolescent girls

BACKGROUND

The possible causes of greater depression among adolescent girls were investigated by examining variation in the influence of genetic and environmental risk factors among 182 prepubertal female, 237 prepubertal male, 314 pubertal female, and 171 pubertal male twin pairs from the Virginia Twin Study of Adolescent Behavioral Development.

OBJECTIVES

To compare the trajectory of depressive symptoms among boys and girls from childhood to adolescence; to analyze the role of genetic, shared, and unique environmental factors in depression among prepubertal and pubertal male and female twins; and to investigate a possible link between liability to depression and one salient index of the child's environment: past-year life events.

METHODS

Child-reported depression was assessed using the Child and Adolescent Psychiatric Interview and ratings of past-year life events and pubertal status obtained by maternal questionnaire and interview, respectively.

RESULTS

The impact of life events on depression was particularly evident in the adolescent girls. The results from model fitting indicate increased heritability for depression in this group, and its long-term consistency was mediated primarily by latent genetic factors. Model fitting also showed that at least part of the liability to depression and to life events can be linked to a common set of genes in the adolescent girls, and there is a notable developmental increase in the genetic variance for life events.

CONCLUSIONS

The greater heritability for depression in pubertal girls, its genetic mediation over time, and the increase in genetic variance for life events may be one possible explanation for the emergence of increased depression among pubertal girls and its persistence through adolescence.

Genetic and environmental influences on subtypes of conduct disorder behavior in boys

Oppositional and conduct disorders are a heterogeneous collection of disruptive behaviors associated with diverse risk factors and varying outcomes. Data from males in the Virginia Twin Study of Adolescent Behavioral Development (VTSABD) are used to explore the relative importance of genetic and environmental influences on four previously described disruptive subtypes: property violations, status violations, oppositional behavior, and aggression. Striking differences between results according to mother and child ratings are found, indicating the need to consider carefully the origin of rater differences. Child ratings indicate support for a general genetic liability, with greatest influence on property violations, oppositional behavior and aggression. Maternal ratings suggest that the genetic factors influencing conduct disorder behavior are more specific to the behavioral area, with the stronger genetic influence on property violations and aggression.

Assortative mating for major psychiatric diagnoses in two population-based samples

BACKGROUND

Previous studies on assortment for psychiatric disorders have reported discrepant findings. We aimed to test whether there is a significant association for psychiatric diagnoses, including alcoholism, generalized anxiety disorder, major depressive disorder, panic disorder and phobias between husbands and wives in two population-based samples. We further evaluated whether marital resemblance occurs primarily within or across psychiatric disorders and if assortment for psychopathology is primary or secondary to assortment for correlated variables.

METHODS

A model for mate selection addressed whether the correlation between mates for psychiatric disorders arises from direct assortment (primary homogamy) or through correlation with other variables for which assortment occurs (secondary homogamy) or through cross-variable assortment. The model accounted for within-person co-morbidity as well as across-spouse data.

RESULTS

Findings suggested that a moderate degree of assortment exists both within and across psychiatric diagnoses. Only a small amount of the observed marital resemblance for mental illness could be explained by assortment for correlated variables such as age, religious attendance and education. Similar results were obtained for the two samples separately and confirmed in their joint analysis, revealing that the co-morbidity and assortment findings, except for the marital correlation for age, religious attendance and education, replicate across samples.

CONCLUSIONS

Significant but moderate primary assortment exists for psychiatric disorders. The bias in twin studies that have ignored the small amount of assortment is negligible.

Short normal children and environmental disadvantage: a longitudinal study of growth and cognitive development from 4 to 11 years

The aim of this investigation was to follow up a sample of exceptionally short but medically healthy children, and a normal comparison group, previously studied at 4 years of age. They lived in an inner-city area which was, on objective criteria, seriously disadvantaged in socioeconomic terms. When first seen at 4 years, cases were significantly impaired in cognitive abilities relative to comparisons, although firstborns were much less severely affected. Of the original 46 cases, 45 were assessed again at 11 years. Most continued to live in the same geographical area. Case children remained exceptionally short, even when parental stature was taken into account, although a degree of catch-up had occurred. One third had special educational needs, and a similar proportion had been referred for speech therapy. Verbal and nonverbal cognitive skills of both case and comparison children had, on the whole, changed little and group differences persisted. In conclusion, short normal children from socioeconomically disadvantaged backgrounds are at high risk of educational failure at elementary school.

Psychiatric epidemiology

Statisticians working in psychiatric epidemiology regularly confront a variety of problems that are rare in other branches of epidemiology. These problems range from the frequent absence of 'objective' biological markers and consequent reliance on informant and self-reports of considerable fallability, to the perhaps corresponding frequent use of multivariate statistical methods such as latent variable modelling. Equally, such difficulties can be regarded as challenges that offer the statistician a critical role.

Genetic "clocks" and "soft" events: a twin model for pubertal development and other recalled sequences of developmental milestones, transitions, or ages at onset

We propose and explore a twin model to examine the basis for synchrony that often characterizes different facets of normal development. In so doing we also present an approach to the analysis of "soft" events; events for which available reports of dates or ages of occurrence are unreliable or inconsistent. Discrepancies among reports are accounted for by a statistical measurement model. This combines current status error reflecting uncertain definition of onset and two mechanisms for the phenomenon of "telescoping," namely, systematic compression of the time scale and heteroscedastic random measurement error. Statistically, the model can be viewed as a mixed generalized linear model with random effects within both mean and variance functions or, alternatively, as involving multiplicative random effects. We apply the model to multiple maternal reports on menarche and onset of breast development in twin daughters. Fitted to data from the Virginia Twin Study Of Adolescent and Behavioral Development by the use of penalized/predictive quasi-likelihood, the model provided much improved estimates of the true age-at-onset distribution as compared to those from a naive analysis. Results suggested that the observed variance was made up almost entirely of genetic variance and measurement error variance due to telescoping and current status errors and that the timing of breast development and menarche are largely under the control of a common set of genes. Results also indicated that maternal recollections of the onset of breast development were both more poorly defined and subject to greater recall errors than maternal recollections of menarche.

Genetic influences on childhood hyperactivity: contrast effects imply parental rating bias, not sibling interaction

BACKGROUND

Previous twin studies of hyperactivity have supported a 'contrast effect', whereby the more hyperactive the rating of one twin, the less the rating of the other. It has not been clear whether contrast effects occur in the twins' behaviour or in the ratings made of their behaviour but the implications for hyperactivity are different under the two models.

METHOD

We use hyperactivity ratings from mothers and teachers for 1644 twin pairs in the Virginia Twin Study of Adolescent Behavioral Development (VTSABD) to explore the origin of contrast effects, making use of independent teacher reports in a proportion of twins. Models were fitted separately for the two informants and jointly to ratings combined through a latent variable, using structural equation modelling.

RESULTS

Models for maternal data confirm the contrast effect previously reported. Teacher ratings show a different form of bias, with both twin confusion and correlated errors representing alternative but not mutually exclusive explanations of the data. Latent variable modelling of the joint responses allowed comparison of a model in which the contrast effect was placed on maternal ratings, representing bias, versus one in which the contrast occurred in the underlying 'true' phenotype. The fit of the former model was significantly better.

CONCLUSIONS

Support is provided for the notion of contrast effects as a form of rater bias in maternal hyperactivity ratings. Different bias in teacher reports highlight that no one report can be considered a gold standard. The extent to which such biases may distort information for other data sources such as sib-pair studies of concordance/discordance is discussed.

Autism, affective and other psychiatric disorders: patterns of familial aggregation

BACKGROUND

The liability to autism confers a risk for a range of more subtle autistic-like impairments, but it remains unclear whether it also confers a risk for other psychiatric disturbances.

METHODS

To investigate this, we studied the pattern of familial aggregation of psychiatric disorders in relatives of 99 autistic and 36 Down's probands, using family history and direct interview measures.

RESULTS

Family history data showed that motor tics, obsessive-compulsive (OCD) and affective disorders were significantly more common in relatives of autistic probands and that individuals with OCD were more likely to exhibit autistic-like social and communication impairments. Direct interview data confirmed the increased rate of affective disorders (especially major depressive disorder) in the first-degree relatives. There was no evidence to indicate significant co-morbidity between affective disorders and the broadly defined phenotype of autism. Moreover, the characteristics of the probands' and the relatives' that were associated with the liability to familiarity of the broader phenotype of autism differed from those that predicted the liability to the familiarity of affective disorders. Examination of the onset of affective disorders suggested that the increased risk was not confined to the period following the birth of the child with autism.

CONCLUSIONS

Overall, the results indicated that OCD, but not affective disorders, may index an underlying liability to autism. They also indicated that the increased risk of affective disorders was not solely the consequence of the stress of raising a child with autism and that further research will be required to clarify the mechanisms involved.

Infant adoption: psychosocial outcomes in adulthood

Adoption studies are able to provide important insights into the impact of changed rearing environments for children's development. A number of studies reporting on the childhood adjustment of adoptees have found an increased risk for disruptive behaviour problems when compared with children brought up in intact families. The long-term implications of adoption for psychosocial adjustment in adult life are less clear. We have used data from the National Child Development Study (NCDS) to examine the psychosocial functioning over a number of life-domains of an unselected sample of adoptees, non-adopted children from similar birth circumstances, and other members of the cohort. Adopted women showed very positive adult adjustment across all the domains examined in this study, whilst our findings suggest some difficulty in two specific domains (employment and social support) for adopted men. Implications of the findings are discussed.

A comparative study of Greek children in long-term residential group care and in two-parent families: II. Possible mediating mechanisms

Forty-one children reared in group care were compared with 41 age- and sex-matched family care children according to interview, questionnaire, and observation measures of behavioural and scholastic functioning. Individual differences in outcome within the group care sample were examined in relation to a range of possible risk/protective indicators. The strongest predictor of outcome proved to be the reason for admission into residential care, with the implication that the outcome was best for children who had experienced stable, harmonious family relationships in their early years. The risk and protective effects applied to both the children's behaviour and scholastic attainments but, although the two were intercorrelated, neither accounted for the other. All subgroups of children in institutional care failed to show a lack of confiding peer relationships, with the pattern of findings suggesting that this stemmed from some aspect of experiences (possibly involving peer relationships) during residential care, as well as from discontinuity in caregiving during the early years.

Genetics and developmental psychopathology: 2. The main effects of genes and environment on behavioral problems in the Virginia Twin Study of Adolescent Behavioral Development

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.

Genetics and developmental psychopathology: 1. Phenotypic assessment in the Virginia Twin Study of Adolescent Behavioral Development

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.

Maternal depressive symptoms and ratings of emotional disorder symptoms in children and adolescents

This study uses information collected on two occasions from a probability sample of families with 8- to 12-year-old children (N = 718) participating in a general population study in 1983 and follow-up in 1987. It focuses on the association between maternal depressive symptoms and emotional disorder in children and adolescents, taking into consideration the influences of informant rating errors, contextual variables (economic disadvantage and family dysfunction), and child gender. Covariance structure analysis revealed a strong association between maternal depressive symptoms in girls (beta = .59 in 1983 and beta = .39 in 1987) but not in boys. This association is independent of the impact of contextual variables and the treatment of teacher rating errors. Among adolescent boys, maternal depressive symptoms are correlated with mother rating errors, suggesting the possible presence of maternal bias.

Diagnosing autism: analyses of data from the Autism Diagnostic Interview

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.