Jennifer Richler

A Multisite Study of the Clinical Diagnosis of Different Autism Spectrum Disorders

CONTEXT Best-estimate clinical diagnoses of specific autism spectrum disorders (autistic disorder, pervasive developmental disorder-not otherwise specified, and Asperger syndrome) have been used as the diagnostic gold standard, even when information from standardized instruments is available. OBJECTIVE To determine whether the relationships between behavioral phenotypes and clinical diagnoses of different autism spectrum disorders vary across 12 university-based sites. DESIGN Multisite observational study collecting clinical phenotype data (diagnostic, developmental, and demographic) for genetic research. Classification trees were used to identify characteristics that predicted diagnosis across and within sites. SETTING Participants were recruited through 12 university-based autism service providers into a genetic study of autism. PARTICIPANTS A total of 2102 probands (1814 male probands) between 4 and 18 years of age (mean [SD] age, 8.93 [3.5] years) who met autism spectrum criteria on the Autism Diagnostic Interview-Revised and the Autism Diagnostic Observation Schedule and who had a clinical diagnosis of an autism spectrum disorder. MAIN OUTCOME MEASURE Best-estimate clinical diagnoses predicted by standardized scores from diagnostic, cognitive, and behavioral measures. RESULTS Although distributions of scores on standardized measures were similar across sites, significant site differences emerged in best-estimate clinical diagnoses of specific autism spectrum disorders. Relationships between clinical diagnoses and standardized scores, particularly verbal IQ, language level, and core diagnostic features, varied across sites in weighting of information and cutoffs. CONCLUSIONS Clinical distinctions among categorical diagnostic subtypes of autism spectrum disorders were not reliable even across sites with well-documented fidelity using standardized diagnostic instruments. Results support the move from existing subgroupings of autism spectrum disorders to dimensional descriptions of core features of social affect and fixated, repetitive behaviors, together with characteristics such as language level and cognitive function.

Cognition assessment using the NIH Toolbox

Vision is a sensation that is created from complex processes and provides us with a representation of the world around us. There are many important aspects of vision, but visual acuity was judged to be the most appropriate vision assessment for the NIH Toolbox for Assessment of Neurological and Behavioral Function, both because of its central role in visual health and because acuity testing is common and relatively inexpensive to implement broadly. The impact of visual impairments on health-related quality of life also was viewed as important to assess, in order to gain a broad view of ones visual function. To test visual acuity, an easy-to-use software program was developed, based on the protocol used by the E-ETDRS. Children younger than 7 years were administered a version with only the letters H, O, T, and V. Reliability and validity of the Toolbox visual acuity test were very good. A 53-item vision-targeted, health-related quality of life survey was also developed.

Association Between Restricted and Repetitive Behaviors and Nonverbal IQ in Children with Autism Spectrum Disorders

The present study explored the relationship between nonverbal IQ and restricted and repetitive behaviors (RRBs) in 830 children with Autism Spectrum Disorders. The role of chronological age as a moderator of this relationship was also investigated. For many behaviors, there was a significant interaction between nonverbal IQ and chronological age, such that nonverbal IQ (NVIQ) was more strongly related to the prevalence of RRBs in older children. For the majority of such behaviors (e.g. repetitive use of objects, hand and finger mannerisms), RRB prevalence was negatively associated with NVIQ. However, the prevalence of certain behaviors (e.g. circumscribed interests) showed positive relationships with NVIQ, which provides some support for the idea of different classes of RRBs. For the severity of different RRBs, there were several significant effects for age and NVIQ, but few interactions.

Predictors of Perceived Negative Impact in Mothers of Children With Autism Spectrum Disorder

Mothers of 110 children with autism spectrum disorders (ASD) were interviewed with the Child and Adolescent Impact Assessment when their children were approximately 9 years old. Regression analyses revealed that African American mothers reported lower levels of perceived negative impact of having a child with ASD than did Caucasian mothers. Higher repetitive behavior scores on the Autism Diagnostic Interview-Revised, lower adaptive behavior scores on the Vineland Adaptive Behavior Scales, and less perceived social support were also significant predictors of higher perceived negative impact. Identifying predictors of perceived negative impact is an important first step in designing interventions to support families and target parents who may be at risk for experiencing higher levels of stress.

Early Regression in Social Communication in Autism Spectrum Disorders: A CPEA Study

In a multisite study of 351 children with autism spectrum disorders, 21 children with developmental delays, and 31 children with typical development, this study used caregiver interviews (i.e., the Autism Diagnostic Interview-Revised) at the time of entry into other research projects and follow-up telephone interviews designed for this project to describe the childrens early acquisition and loss of social-communication milestones. Children who had used words spontaneously and meaningfully and then stopped talking were described by their caregivers as showing more gestures, greater participation in social games, and better receptive language before the loss and fewer of these skills after the loss than other children with autism spectrum disorders. A significant minority of children with autism without word loss showed a very similar pattern of loss of social-communication skills, a pattern not observed in the children with developmental delays or typical development.

II. NIH Toolbox Cognition Battery (CB): measuring executive function and attention.

In this chapter, we discuss two measures designed to assess executive function (EF) as part of the NIH Toolbox Cognition Battery (CB) and report pediatric data from the validation study. EF refers to the goal-directed cognitive control of thought, action, and emotion. Two measures were adapted for standardized computer administration: the Dimensional Change Card Sort (a measure of cognitive flexibility) and a flanker task (a measure of inhibitory control in the context of selective visual attention). Results reveal excellent developmental sensitivity across childhood, excellent reliability, and (in most cases) excellent convergent validity. Correlations between the new NIH Toolbox measures and age were higher for younger children (3-6 years) than for older children (8-15 years), and evidence of increasing differentiation of EF from other aspects of cognition (indexed by receptive vocabulary) was obtained.

NIH Toolbox Cognition Battery (CB): Validation of Executive Function Measures in Adults

This study describes psychometric properties of the NIH Toolbox Cognition Battery (NIHTB-CB) executive function measures in an adult sample. The NIHTB-CB was designed for use in epidemiologic studies and clinical trials for ages 3 to 85. A total of 268 self-described healthy adults were recruited at four university-based sites, using stratified sampling guidelines to target demographic variability for age (20-85 years), gender, education and ethnicity. The NIHTB-CB contains two computer-based instruments assessing executive function: the Dimensional Change Card Sort (a measure of cognitive flexibility) and a flanker task (a measure of inhibitory control and selective attention). Participants completed the NIHTB-CB, corresponding gold standard convergent and discriminant measures, and sociodemographic questionnaires. A subset of participants (N=89) was retested 7 to 21 days later. Results reveal excellent sensitivity to age-related changes during adulthood, excellent test-retest reliability, and adequate to good convergent and discriminant validity. The NIH Toolbox EF measures can be used effectively in epidemiologic and clinical studies.