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Adrian Angold

Publications and source records attributed to Adrian Angold.

At least 19 recordsLinked to original sources
PubMed2006

Bayesian semi-parametric ROC analysis.

This paper describes a semi-parametric Bayesian approach for estimating receiver operating characteristic (ROC) curves based on mixtures of Dirichlet process priors (MDP). We address difficulties in modelling the underlying distribution of screening scores due to non-normality that may lead to incorrect choices of diagnostic cut-offs and unreliable estimates of prevalence of the disease. MDP is a robust tool for modelling non-standard diagnostic distributions associated with imperfect classification of an underlying diseased population, for example, when a diagnostic test is not a gold standard. For posterior computations, we propose an efficient Gibbs sampling framework based on a finite-dimensional approximation to MDP. We show, using both simulated and real data sets, that MDP modelling for ROC curve estimation closely parallels the frequentist kernel density estimation (KDE) approach.

Adolescent↗
PubMed2006

10-year research update review: the epidemiology of child and adolescent psychiatric disorders: II. Developmental epidemiology.

OBJECTIVE: To describe the growth of developmental epidemiology in the past decade and to illustrate it with examples of recent studies. METHOD: A review of publications on developmental epidemiology in the past 10 years and a discussion of some key examples. RESULTS: The authors describe how the interaction between developmental psychopathology and psychiatric epidemiology has produced developmental epidemiology, the study of patterns of distribution of psychiatric disorders in time as well as in space. They give two examples of the kinds of questions that developmental epidemiology can help to answer: (1) Is the prevalence of autism increasing? Does the use of vaccines explain the increase? (2) Is there an epidemic of child and adolescent depression? Finally, they describe two areas of science that are beginning to inform developmental epidemiology: molecular genetics and the use of biological measures of stress. CONCLUSIONS: While child and adolescent psychiatric epidemiology continues, as described in the first of these reviews, to address questions of prevalence and burden, it has also expanded into new areas of research in the past decade. In the next decade, longitudinal epidemiological data sets with their rich descriptive data on psychopathology and environmental risk over time and the potential to add biological measures will provide valuable resources for research into gene-environment correlations and interactions.

Adolescent↗
PubMed2006

Test-Retest Reliability of the Preschool Age Psychiatric Assessment (PAPA).

OBJECTIVE: To examine the test-retest reliability of a new interviewer-based psychiatric diagnostic measure (the Preschool Age Psychiatric Assessment) for use with parents of preschoolers aged 2 to 5 years. METHOD: A total of 1,073 parents of children attending a large pediatric clinic completed the Child Behavior Checklist 1 1/2-5. For 18 months, 193 parents of high scorers and 114 parents of low scorers were interviewed on two occasions an average of 11 days apart. RESULTS: Estimates of diagnostic reliability were very similar to those obtained from interviews with parents of older children and adults, with kappas ranging from 0.36 to 0.79. Test-retest intraclass correlations for DSM-IV syndrome scale scores ranged from 0.56 to 0.89. There were no significant differences in reliability by age, sex, or race (African American versus non-African American). CONCLUSIONS: The Preschool Age Psychiatric Assessment provides a reasonably reliable standardized measure of DSM-IV psychiatric symptoms and disorders in preschoolers for use in both research and clinical service evaluations of preschoolers as young as 2 years old.

Child Behavior Disorders↗
PubMed2005

Application of Bayesian inference using Gibbs sampling to item-response theory modeling of multi-symptom genetic data.

Several "genetic" item-response theory (IRT) models are fitted to the responses of 1086 adolescent female twins to the 33 multi-category item Mood and Feeling Questionnaire relating to depressive symptomatology in adolescence. A Markov-chain Monte Carlo (MCMC) algorithm is used within a Bayesian framework for inference using Gibbs sampling, implemented in the program WinBUGS 1.4. The final model incorporated separate genetic and non-shared environmental traits ("A and E") and item-specific genetic effects. Simpler models gave markedly poorer fit to the observations judged by the deviance information criterion (DIC). The common genetic factor showed major loadings on melancholic items, while the environmental factor loaded most highly on items relating to self-deprecation. The MCMC approach provides a convenient and flexible alternative to Maximum Likelihood for estimating the parameters of IRT models for relatively large numbers of items in a genetic context. Additional benefits of the IRT approach are discussed including the estimation of latent trait scores, including genetic factor scores, and their sampling errors.

Adolescent↗
PubMed2005

The developmental epidemiology of anxiety disorders: phenomenology, prevalence, and comorbidity.

This article argues that the quality of diagnostic tools used to measure anxiety disorders in children and adolescents has improved enormously in the past few years. As a result, prevalence estimates are less erratic, understanding of comorbidity is increasing, and the role of impairment as a criterion for "caseness" is considered more carefully. Several of the instruments developed for epidemiologic research are now being used in clinical settings. Further integration of laboratory methods and clinical and epidemiologic ideas will benefit children with anxiety disorders and their families.

Adolescent↗
PubMed2005

10-year research update review: the epidemiology of child and adolescent psychiatric disorders: I. Methods and public health burden.

OBJECTIVE: To review recent progress in child and adolescent psychiatric epidemiology in the area of prevalence and burden. METHOD: The literature published in the past decade was reviewed under two headings: methods and findings. RESULTS: Methods for assessing the prevalence and community burden of child and adolescent psychiatric disorders have improved dramatically in the past decade. There are now available a broad range of interviews that generate DSM and ICD diagnoses with good reliability and validity. Clinicians and researchers can choose among interview styles (respondent based, interviewer based, best estimate) and methods of data collection (paper and pencil, computer assisted, interviewer or self-completion) that best meet their needs. Work is also in progress to develop brief screens to identify children in need of more detailed assessment, for use by teachers, pediatricians, and other professionals. The median prevalence estimate of functionally impairing child and adolescent psychiatric disorders is 12%, although the range of estimates is wide. Disorders that often appear first in childhood or adolescence are among those ranked highest in the World Health Organization's estimates of the global burden of disease. CONCLUSIONS: There is mounting evidence that many, if not most, lifetime psychiatric disorders will first appear in childhood or adolescence. Methods are now available to monitor youths and to make early intervention feasible.

Adolescent↗
PubMed2005

Defining oppositional defiant disorder.

BACKGROUND: ICD-10 and DSM-IV include similar criterial symptom lists for conduct disorder (CD) and oppositional defiant disorder (ODD), but while DSM-IV treats each list separately, ICD-10 considers them jointly. One consequence is that ICD-10 identifies a group of children with ODD subtype who do not receive a diagnosis under DSM-IV. METHODS: We examined the characteristics of this group of children using the Great Smoky Mountains Study of children in the community aged 9-16. This study provided child and parent reports of symptoms and psychosocial impairment assessed with standardised diagnostic interviews. RESULTS: Children who received an ICD-10 diagnosis but not a DSM-IV diagnosis showed broadly similar levels of psychiatric comorbidity, delinquent activity and psychosocial impairment to those who met DSM-IV criteria in both cross-sectional and longitudinal analyses. CONCLUSIONS: These results indicate that DSM-IV excludes from diagnosis children who receive an ICD-10 diagnosis of CD (ODD sub-type), and who are substantially disturbed. Methods of redressing this situation are considered.

Adolescent↗
PubMed2004

Effects of age at first substance use and psychiatric comorbidity on the development of substance use disorders.

In this paper, we examine the effects of age at first substance use, and history of psychiatric disorders, on the development of substance use disorder (SUD) by age 16. We use a prospective, longitudinal design to disaggregate the effects of age at first use and time since first use on the development of adolescent SUD. Second, we test the hypothesis that adolescent SUD is an unlikely progression from early substance use unless children also show other early conduct problems. A population sample of 1,420 children from the Great Smoky Mountains Study (GSMS) was assessed annually between ages 9 and 16. Logistic regression models were applied within the hierarchical Bayesian framework, where the covariate effects were described by time-varying parameters having a first-order auto-regressive prior distribution. Posterior analyses based on a Gibbs sampling approach revealed that, controlling for years of exposure, the risk of transition to SUD increased with age at onset for onsets before age 13, but began to fall for onset at 14. Among users, use alone, without early conduct problems, led to a 11% prevalence of SUD by age 16. Past conduct disorder (CD) had a strong additive effect at ages 13-15, but at age 16, when substance use and abuse became more normative, the excess risk from prior CD decreased. Boys, but not girls, with a history of depression were at increased risk of SUD. Anxiety increased the risk of SUD in girls at age 16, but not before that. Results only partially support the study hypothesis; early use was a major predictor of adolescent SUD even in the absence of CD.

Adolescent↗
PubMed2004

Testosterone, antisocial behavior, and social dominance in boys: pubertal development and biosocial interaction.

BACKGROUND: Studies linking testosterone and antisocial behavior in humans have produced mixed results. Adolescence offers a promising period to study this relationship; circulating testosterone increases dramatically in boys during puberty, and antisocial behavior increases during the same period. METHODS: Our analyses were based on boys aged 9-15 years who were interviewed during the first three waves of the Great Smoky Mountains Study. Measures included interview assessment of DSM-IV conduct disorder (CD) symptoms and diagnosis, blood spot measurement of testosterone, Tanner staging of pubertal development, and assessment of leadership behaviors and peer deviance. RESULTS: The adolescent rise in CD was primarily attributable to an increase in nonphysically aggressive behaviors. Increasing levels of circulating testosterone and association with deviant peers contributed to these age trends. There was no evidence that physical aggression was related to high testosterone. Evidence of biosocial interactions was identified; testosterone was related to nonaggressive CD symptoms in boys with deviant peers and to leadership in boys with nondeviant peers. CONCLUSIONS: The results are consistent with the hypothesis that testosterone relates to social dominance, with the assumption that behaviors associated with dominance differ according to social context.

Adolescent↗
PubMed2004

Informant disagreement for separation anxiety disorder.

OBJECTIVE: To characterize informant disagreement for separation anxiety disorder (SAD). METHOD: The sample comprised 2,779 8- to 17-year-old twins from a community-based registry. Children and their parents completed a personal interview about the child's psychiatric history. Parents completed a personal interview about their own psychiatric history and a questionnaire about their marital relationship. RESULTS: Informant agreement for SAD ranged between chance and extremely poor. Most cases of SAD were diagnosed by interview with only one informant. SAD diagnosed only by child interview was associated with an increased odds of father-rated oppositional defiant disorder, and vice versa. SAD diagnosed only by parent interview was predicted by the parental informant's history of antisocial personality disorder. SAD diagnosed only by paternal interview was also predicted by mother-rated marital conflict and dissatisfaction. CONCLUSIONS: Parents and children rarely agree about the presence of any level of child separation anxiety. A symptom "or-rule" mostly indexes diagnoses based on interview with only one informant, but the relative validity of such diagnoses remains unclear.

Adolescent↗
PubMed2004

Genetic and environmental influences on the relative timing of pubertal change.

A multicategory item-response theory model was developed to characterize developmental changes in three items relating to the assessment of puberty in adolescent twin girls and boys. The model allowed for the fixed effects of age on probability of endorsing the responses and for the random effects of individual differences on the timing of pubertal changes relative to chronological age. In girls, the model was applied three-wave data on twin pairs (N = 414 female monozygotic [MZ] and 197 female dizygotic [DZ] pairs) and female twins from boy-girl pairs (N = 300 twins) from the Virginia Twin Study of Adolescent Behavioral Development. In boys, the data comprised 318 MZ and 185 DZ pairs and 297 male twins from boy-girl pairs. A total of 3172 and 2790 individual twin assessments were available in girls and boys, respectively, spanning ages 8-17 years. The availability of twin data allows the contributions of genes, the shared environment and individual unique environmental experiences to be resolved in the relative timing of pubertal changes. Parameters of the mixed model including fixed effects of age and random effects of genes and environment were estimated by Markov Chain Monte Carlo simulations using the BUGS algorithm for Gibbs sampling. The estimated standard deviation of random differences in the timing of puberty relative to age was 0.96 years in girls and 1.01 years in boys. The estimated intraclass correlations for the relative timing of pubertal changes were 0.99 +/-0.01 in MZ girls, 0.52 +/-0.02 in DZ girls, 0.88 +/-0.04 in MZ boys and 0.44+/-0.02 in DZ boys, indicating a very large contribution of genetic factors to the relative timing of pubertal change in both sexes. Additive genetic factors account for an estimated 96.3+/-3.3% of the total variance in random effects in girls and 88.0+/-3.6% in boys. Shared environmental influences account for 3.6+/-3.4% in girls and 0% in boys. In girls, nonshared environmental effects explain 0.1+/-0.1% of the total residual variance. The comparable figure in boys is 12.0+/-3.6%.

Adolescent↗
PubMed2003

Relationships between poverty and psychopathology: a natural experiment.

CONTEXT: Social causation (adversity and stress) vs social selection (downward mobility from familial liability to mental illness) are competing theories about the origins of mental illness. OBJECTIVE: To test the role of social selection vs social causation of childhood psychopathology using a natural experiment. DESIGN: Quasi-experimental, longitudinal study. POPULATION AND SETTING: A representative population sample of 1420 rural children aged 9 to 13 years at intake were given annual psychiatric assessments for 8 years (1993-2000). One quarter of the sample were American Indian, and the remaining were predominantly white. Halfway through the study, a casino opening on the Indian reservation gave every American Indian an income supplement that increased annually. This increase moved 14% of study families out of poverty, while 53% remained poor, and 32% were never poor. Incomes of non-Indian families were unaffected. MAIN OUTCOME MEASURES: Levels of Diagnostic and Statistical Manual of Mental Disorders, Fourth Edition, psychiatric symptoms in the never-poor, persistently poor, and ex-poor children were compared for the 4 years before and after the casino opened. RESULTS: Before the casino opened, the persistently poor and ex-poor children had more psychiatric symptoms (4.38 and 4.28, respectively) than the never-poor children (2.75), but after the opening levels among the ex-poor fell to those of the never-poor children, while levels among those who were persistently poor remained high (odds ratio, 1.50; 95% confidence interval, 1.08-2.09; and odds ratio, 0.91; 95% confidence interval, 0.77-1.07, respectively). The effect was specific to symptoms of conduct and oppositional defiant disorders. Anxiety and depression symptoms were unaffected. Similar results were found in non-Indian children whose families moved out of poverty during the same period. CONCLUSIONS: An income intervention that moved families out of poverty for reasons that cannot be ascribed to family characteristics had a major effect on some types of children's psychiatric disorders, but not on others. Results support a social causation explanation for conduct and oppositional disorder, but not for anxiety or depression.

Adolescent↗
PubMed2003

Maternal smoking during pregnancy and risk to boys' conduct disturbance: an examination of the causal hypothesis.

BACKGROUND: We undertook this study to determine whether the widely replicated link between maternal smoking and conduct disturbance (Cd) is better explained by a model of direct causation or of mother-offspring transmission of a latent Cd variable. METHODS: Family data collected on 538 adolescent twin boys from the Virginia Twin Study of Adolescent Behavioral Development (VTSABD) was used to compare two alternative models: 1) a model composed of a latent transmissible factor that influences mother's juvenile conduct symptoms, smoking during pregnancy, and subsequent Cd and smoking in her adolescent boys; and 2) a model specifying a direct causal path from mother's smoking to child Cd. RESULTS: The maternal-offspring transmission model fit the data as well as a model specifying a direct causal path from maternal smoking to child Cd. CONCLUSIONS: Our results suggest that the association between maternal smoking during pregnancy and boys' Cd symptoms may be attributed to the transmission of a latent Cd factor and not to a direct effect of the smoking. Our results challenge previous findings of a direct effect of prenatal smoke exposure on risk to Cd once other etiologic factors are considered.

Adolescent↗
PubMed2003

Prevalence and development of psychiatric disorders in childhood and adolescence.

BACKGROUND: This longitudinal community study assessed the prevalence and development of psychiatric disorders from age 9 through 16 years and examined homotypic and heterotypic continuity. METHODS: A representative population sample of 1420 children aged 9 to 13 years at intake were assessed annually for DSM-IV disorders until age 16 years. RESULTS: Although 3-month prevalence of any disorder averaged 13.3% (95% confidence interval [CI], 11.7%-15.0%), during the study period 36.7% of participants (31% of girls and 42% of boys) had at least 1 psychiatric disorder. Some disorders (social anxiety, panic, depression, and substance abuse) increased in prevalence, whereas others, including separation anxiety disorder and attention-deficit/hyperactivity disorder (ADHD), decreased. Lagged analyses showed that children with a history of psychiatric disorder were 3 times more likely than those with no previous disorder to have a diagnosis at any subsequent wave (odds ratio, 3.7; 95% CI, 2.9-4.9; P<.001). Risk from a previous diagnosis was high among both girls and boys, but it was significantly higher among girls. Continuity of the same disorder (homotypic) was significant for all disorders except specific phobias. Continuity from one diagnosis to another (heterotypic) was significant from depression to anxiety and anxiety to depression, from ADHD to oppositional defiant disorder, and from anxiety and conduct disorder to substance abuse. Almost all the heterotypic continuity was seen in girls. CONCLUSIONS: The risk of having at least 1 psychiatric disorder by age 16 years is much higher than point estimates would suggest. Concurrent comorbidity and homotypic and heterotypic continuity are more marked in girls than in boys.

Adolescent↗
PubMed2003

Natural categories or fundamental dimensions: on carving nature at the joints and the rearticulation of psychopathology.

The question of whether to view psychopathology as categorical or dimensional continues to provoke debate. We review the many facets of this argument. These include the pragmatics of measurement; the needs of clinical practice; our ability to distinguish categories from dimensions empirically; methods of analysis appropriate to each and how they relate; and the potential theoretical biases associated with each approach. We conclude that much of the debate is misconceived in that we do not observe pathology directly; rather, we observe its properties. The same pathology can have some properties that are most easily understood using a dimensional conceptualization while at the same time having other properties that are best understood categorically. We suggest replacing Meehl's analogy involving qualitatively distinct species with an alternative analogy with the "duality" of light, a phenomenon with both wave- and particle-like properties.

Child↗
PubMed2003

Relations between Continuous Performance Test performance measures and ADHD behaviors.

The Conners' Continuous Performance Test (CPT) is a neuropsychological task that has repeatedly been shown to differentiate ADHD from normal groups. Several variables may be derived from the Conners' CPT including errors of omission and commission, mean hit reaction time(RT), mean hit RT standard error, d', and beta. What each CPT parameter actually assesses has largely been based upon clinical assumptions and the face validity of each measure (e.g., omission errors measure inattention, commission errors measure impulsivity). This study attempts to examine relations between various CPT variables and phenotypic behaviors so as to better understand the various CPT variables. An epidemiological sample of 817 children was administered the Conners' CPT. Diagnostic interviews were conducted with parents to determine ADHD symptom profiles for all children. Children diagnosed with ADHD had more variable RTs, made more errors of commission and omission, and demonstrated poorer perceptual sensitivity than nondiagnosed children. Regarding specific symptoms, generalized estimating equations (GEE) and ANCOVAs were conducted to determine specific relationships between the 18 DSM-IV ADHD symptoms and 6 CPT parameters. CPT performance measures demonstrated significant relationships to ADHD symptoms but did not demonstrate symptom domain specificity according to a priori assumptions. Overall performance on the two signal detection measures, d' and beta, was highly related to all ADHD symptoms across symptom domains. Further, increased variability in RTs over time was related to most ADHD symptoms. Finally, it appears that at least 1 CPT variable, mean hit RT, is minimally related to ADHD symptoms as a whole, but does demonstrate some specificity in its link with symptoms of hyperactivity.

Algorithms↗
PubMed2003

Continuous performance test performance in a normative epidemiological sample.

A 14-min continuous performance test (CPT) requiring a high rate of responding was administered to a probability-weighted random sample of 816 9-17-year-old children drawn from a population of 17,117 children in an ongoing epidemiological and longitudinal study in Western North Carolina. Systematic main effects of improved performance with older age were found in this age range for all variables, including reaction time (RT), RT standard error, errors of omission, errors of commission, and signal detection parameters (d' and beta). Significant gender main effects included more impulsive errors, less variability, and faster RT by males, with no interactions between age and gender. There were no main effects of ethnicity or interactions of ethnicity with age and/or gender. Large main effects of interstimulus interval (ISI; 1, 2, or 4-s intervals) and time block were present for most CPT performance measures. The normative data from the CPT should provide a useful framework for interpreting similar data in future studies of child and adolescent psychopathology.

Adolescent↗