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A Pickles

Publications and source records attributed to A Pickles.

At least 37 records · Page 2Linked to original sources
PubMed2000

Genetic and environmental causes of covariation in interview assessments of disruptive behavior in child and adolescent twins.

Multirater, face-to-face, interview data relating to conduct disorder (CD), oppositional-defiant disorder (ODD), and inattentive, impulsive, and hyperactive components of attention-deficit hyperactivity disorder (ADHD) in a population-based sample of 1376 pairs of 8- to 16-year-old MZ and DZ twins are analyzed to examine (1) the genetic and environmental causes of correlation among ratings of ODD and CD symptoms and (2) the pattern of genetic and environmental correlation among the three components of ADHD. Parental ratings of ADHD showed marked sibling contrast effects, specific within raters but partly common across components. After these effects were removed, there was a modest genetic correlation between maternal and paternal ratings, but genetic effects were virtually uncorrelated across boys and girls. Genetic correlations among inattention, impulsivity, and hyperactivity were all large but fell well short of unity. There was little evidence that counts of symptoms of CD and ODD were genetically independent but the genetic correlations among ratings of twins, mothers, and fathers were all relatively modest. ODD and CD showed much higher genetic correlations across sexes than did the measures of ADHD. There was no evidence of rater contrast effects or of shared family environment influences in the twin resemblance for ODD and CD.

Adolescent↗
PubMed2000

Complementary approaches to the assessment of personality disorder. The Personality Assessment Schedule and Adult Personality Functioning Assessment compared.

BACKGROUND: Current concepts and measures of personality disorder are in many respects unsatisfactory. AIMS: To establish agreement between two contrasting measures of personality disorder, and to compare subject-informant agreement on each. To examine the extent to which trait abnormality can be separated from interpersonal and social role dysfunction. METHOD: Fifty-six subjects and their closest informants were interviewed and rated independently. Personality functioning was assessed using a modified Personality Assessment Schedule (M-PAS), and the Adult Personality Functioning Assessment (APFA). RESULTS: Subject-informant agreement on the M-PAS was moderately good, and agreement between the M-PAS and the APFA, across and within subjects and informants, was comparable to that for the M-PAS. This was equally the case when M-PAS trait plus impairment scores and trait abnormality scores were used. CONCLUSIONS: The M-PAS and the APFA are probably assessing similar constructs. Trait abnormalities occur predominantly in an interpersonal context and could be assessed within that context.

Adult↗
PubMed2000

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.

Attention Deficit Disorder with Hyperactivity↗
PubMed2000

Variable expression of the autism broader phenotype: findings from extended pedigrees.

Factors influencing the rate, form, and severity of phenotypic expression among relatives of autistic probands are examined. Family history data on 3095 first- and second-degree relatives and cousins from 149 families with a child with autism and 36 families with a child with Down syndrome are studied. The results provide further evidence of an increased risk among autism relatives for the broadly defined autism phenotype. Of proband characteristics, severity of autism and obstetric optimality were confirmed as being related to familial loading for probands with speech. There was little variation in loading among probands lacking speech. The type of phenotypic profile reported in relatives appeared little influenced by characteristics of the relative or the proband, except for variation by degree of relative, parental status of relative, and perhaps proband's birth optimality score. Phenotypic rates among parents suggested reduced fitness for the severest and more communication-related forms of expression but not for the more mild and social forms of expression. Patterns of expression within the families did not support a simple X-linked nor an imprinted X-linked mode of inheritance. The basis for sex differences in rates of expression is discussed.

Autistic Disorder↗
PubMed2000

The autism diagnostic observation schedule-generic: a standard measure of social and communication deficits associated with the spectrum of autism.

The Autism Diagnostic Observation Schedule-Generic (ADOS-G) is a semistructured, standardized assessment of social interaction, communication, play, and imaginative use of materials for individuals suspected of having autism spectrum disorders. The observational schedule consists of four 30-minute modules, each designed to be administered to different individuals according to their level of expressive language. Psychometric data are presented for 223 children and adults with Autistic Disorder (autism), Pervasive Developmental Disorder Not Otherwise Specified (PDDNOS) or nonspectrum diagnoses. Within each module, diagnostic groups were equivalent on expressive language level. Results indicate substantial interrater and test-retest reliability for individual items, excellent interrater reliability within domains and excellent internal consistency. Comparisons of means indicated consistent differentiation of autism and PDDNOS from nonspectrum individuals, with some, but less consistent, differentiation of autism from PDDNOS. A priori operationalization of DSM-IV/ICD-10 criteria, factor analyses, and ROC curves were used to generate diagnostic algorithms with thresholds set for autism and broader autism spectrum/PDD. Algorithm sensitivities and specificities for autism and PDDNOS relative to nonspectrum disorders were excellent, with moderate differentiation of autism from PDDNOS.

Autistic Disorder↗
PubMed1999

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.

Adolescent↗
PubMed1999

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.

Adult↗
PubMed1999

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.

Administration, Cutaneous↗
PubMed1999

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.

Adaptation, Psychological↗
PubMed1999

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.

Adolescent↗
PubMed1999

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.

Adolescent↗
PubMed1998

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.

Adaptation, Psychological↗
PubMed1998

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.

Adolescent↗
PubMed1998

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.

Adolescent↗
PubMed1998

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.

Adolescent↗
PubMed1998

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.

Adolescent↗
PubMed1998

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.

Adult↗