Toward a developmental operational definition of autism.

Traditional approaches to diagnosing autism emphasize delays in communication and socialization. Traditional diagnostic schemes typically list symptoms (e.g., lack of eye contact), but provide little guidance on how to incorporate information about developmental level in making a diagnosis. Because standardized measures of adaptive behavior can provide information about children's communication, socialization, and other behavior relative to their age, they may be useful tools for diagnosing autism. This study investigated the ability of the Vineland Adaptive Behavior Scales to identify children with autism. Vineland scores and measures of intellectual functioning were obtained for children with autism, PDDNOS, and other developmental disorders (DD). Discriminant function analyses indicated that the autism and combined nonautism (PDDNOS and DD) groups could be differentiated on the basis of socialization, daily living skills, and serious maladaptive behaviors. Socialization alone accounted for 48% of the variance in diagnosis. Using regression analyses derived from a large normative sample, adaptive behavior scores were predicted from chronological age (CA) and mental age (MA). Socialization scores in the autism group were substantially below the level predicted from CA or MA. An index derived from the ratio of actual to predicted socialization scores correctly classified 86% of both autism and nonautism cases. Findings suggest that comparison of obtained Vineland socialization scores to those predicted by CA or MA may be useful in clarifying the diagnosis of autism.

Recent advances in the assessment of intelligence and cognition.

In this paper, we review current issues in cognitive assessment. After addressing important definitional and theoretical issues, we discuss some recently developed cognitive assessment instruments as well as some recently revised instruments. Tests that are scheduled for revision will also be mentioned. As most readers are generally familiar with the widely used and nationally standardized IQ tests, we will summarize these tests according to their general usage. The testing of intelligence has been a major focus and contribution since the early days of Psychology, when the birthplace of the intelligence testing movement began in France with the work of Alfred Binet toward the end of the 19th century. Many of the most widely known and used IQ tests have been developed in the U.S.A. and are used internationally. In addition, other IQ tests have been developed in many other countries outside the U.S.A. The use of IQ tests and selected assessment considerations will be reviewed. Finally, we make some predictions about the future role of cognitive assessment in the coming century.

Outcome of children in the indomethacin intraventricular hemorrhage prevention trial.

BACKGROUND: For preterm infants, intraventricular hemorrhage (IVH) may be associated with adverse neurodevelopmental outcome. We have demonstrated that early low-dose indomethacin treatment is associated with a decrease in both the incidence and severity of IVH in very low birth weight preterm infants. In addition, we hypothesized that the early administration of low-dose indomethacin would not be associated with an increase in the incidence of neurodevelopmental handicap at 4.5 years of age in our study children. METHODS: To test this hypothesis, we provided neurodevelopmental follow-up for the 384 very low birth weight survivors of the Multicenter Randomized Indomethacin IVH Prevention Trial. Three hundred thirty-seven children (88%) were evaluated at 54 months' corrected age, and underwent neurodevelopmental examinations, including the Wechsler Preschool and Primary Scale of Intelligence-Revised (WPPSI-R), the Peabody Picture Vocabulary Test-Revised (PPVT-R), and standard neurologic examinations. RESULTS: Of the 337 study children, 170 had been randomized to early low-dose indomethacin therapy and 167 children had received placebo. Twelve (7%) of the 165 indomethacin children and 11 (7%) of the 158 placebo children who underwent neurologic examinations were found to have cerebral palsy. For the 233 English-monolingual children for whom cognitive outcome data follow, the mean gestational age was significantly younger for the children who received indomethacin than for those who received placebo. In addition, although there were no differences in the WPPSI-R or the PPVT-R scores between the 2 groups, analysis of the WPPSI-R full-scale IQ by function range demonstrated significantly less mental retardation among those children randomized to early low-dose indomethacin (for the indomethacin study children, 9% had an IQ <70, 12% had an IQ of 70-80, and 79% had an IQ >80, compared with the placebo group, for whom 17% had an IQ <70, 18% had an IQ of 70-80, and 65% had an IQ >80). Indomethacin children also experienced significantly less difficulty with vocabulary skills as assessed by the PPVT-R when compared with placebo children. CONCLUSIONS: These data suggest that, for preterm neonates, the early administration of low-dose indomethacin therapy is not associated with adverse neurodevelopmental function at 54 months' corrected age.

A normed study of face recognition in autism and related disorders.

Although the interpretation of studies of face recognition in older children, adolescents, and adults with autism is complicated by the fact that participating samples and adopted methodologies vary significantly, there is nevertheless strong evidence indicating processing peculiarities even when task performance is not deficient. Much less is known about face recognition abilities in younger children with autism. This study employed a well-normed task of face recognition to measure this ability in 102 young children with autism, pervasive developmental disorder not otherwise specified (PDDNOS), and non-PDD disorders (mental retardation and language disorders) matched on chronological age and nonverbal mental age, and in a subsample of 51 children divided equally in the same three groups matched on chronological age and verbal mental age. There were pronounced deficits of face recognition in the autistic group relative to the other nonverbally matched and verbally matched groups. Performance on two comparison tasks did not reveal significant differences when verbal ability was adequately controlled. We concluded that young children with autism have face recognition deficits that cannot be attributed to overall cognitive abilities or task demands. In contrast to controls, there was a lower correlation between performance on face recognition and nonverbal intelligence, suggesting that in autism face recognition is less correlated with general cognitive capacity. Contrary to our expectation, children with PDDNOS did not show face recognition deficits.

The Vineland Adaptive Behavior Scales: supplementary norms for individuals with autism.

Vineland Adaptive Behavior Scales Special Population norms are presented for four groups of individuals with autism: (a) mute children under 10 years of age; (b) children with at least some verbal skills under 10 years of age; (c) mute individuals who are 10 years of age or older; and (d) individuals with at least some verbal skills who are 10 years of age or older. The sample included 684 autistic individuals ascertained from cases referred for the DSM-IV autism/PDD field trial collaborative study and five university sites with expertise in autism. Young children had higher standard scores than older individuals across all Vineland domains. In the Communication domain, younger verbal children were least impaired, older mute individuals most impaired, and younger mute and older verbal individuals in the midrange. Verbal individuals achieved higher scores in Daily Living Skills than mute individuals. The expected profile of a relative weakness in Socialization and relative strength in Daily Living Skills was obtained with age-equivalent but not standard scores. Results high-light the importance of employing Vineland special population norms as well as national norms when evaluating individuals with autism.

Validity and neuropsychological characterization of Asperger syndrome: convergence with nonverbal learning disabilities syndrome.

The authors investigated the validity of Asperger Syndrome (AS) by comparing the neuropsychological profiles in this condition and Higher-Functioning Autism (HFA). Diagnostic assignment followed a stringent procedure based on ICD-10 research criteria for the two disorders. The groups had comparable age and Full Scale IQ distributions. The groups differed significantly in 11 neuropsychological areas. The profile obtained for individuals with AS coincided closely with a cluster of neuropsychological assets and deficits captured by the term nonverbal learning disabilities, suggesting an empirical distinction from HFA.

Sex differences in pervasive developmental disorders.

Assessed differences in sex ratio, severity of associated mental retardation, and various metrics of severity of autism in autistic, PDD-NOS, and developmentally disordered (non-PDD) cases. Males with autism were more frequent than females, particular at higher IQ levels. The three clinical groups differed, in expected ways, in the various measures of severity of autism with the PDD-NOS cases being intermediate between the strictly diagnosed autistic group and the non-PDD developmental disordered group. Sex differences were primarily confined to IQ; sex differences in other metrics of severity of autism were not prominent. Implications for future research are discussed.

Quantifying social development in autism.

OBJECTIVE: This study was concerned with the development of quantitative measures of social development in autism. METHOD: Multiple regression equations predicting social, communicative, and daily living skills on the Vineland Adaptive Behavior Scales were derived from a large, normative sample and applied to groups of autistic and nonautistic, developmentally disordered children. Predictive models included either mental or chronological age and other relevant variables. RESULTS: Social skills in the autistic group were more than two standard deviations below those predicted by their mental age; an index derived from the ratio of actual to predicted social skills correctly classified 94% of the autistic and 92% of the nonautistic, developmentally disordered cases. CONCLUSIONS: The findings are consistent with the idea that social disturbance is central in the definition of autism. The approach used in this study has potential advantages for providing more precise measures of social development in autism.

Assessing the reliability of clinical scales when the data have both nominal and ordinal features: proposed guidelines for neuropsychological assessments.

The purpose of this article is to present, for the first time, a comprehensive methodology for assessing the reliability of a clinical scale that is frequently utilized in neuropsychological research and in biomedical studies, more generally. The dichotomous-ordinal scale is characterized by a single category of "absence" and two or more ordinalized categories of "presence" of a symptom trait, state, or behavior, and it also has special properties that need to be understood in order for its reliability to be appropriately assessed. Using the Brief Psychiatric Rating Scale (BPRS) as a clinical example, we cover the principles of expressing scale reliability in terms of a dichotomy ("absence" - "presence" of a given BPRS symptom); as a trichotomy ("none"; "mild to moderate" symptomatology; and "severe" symptomatology); and as the full 7-category dichotomous-ordinal scale: "none," "very mild," "mild," "moderate," "moderately severe," "severe," and "extremely severe." Criteria are presented that can be used to evaluate which of these three formats produces the most reliable results. Finally, we address, with a second sample, the important issue of replication, or whether the original reliability findings generalize to other independent populations.

K-ABC profiles in children with fragile X syndrome, Down syndrome, and nonspecific mental retardation.

Etiology-specific profiles of intellectual abilities were compared in three groups of males with mental retardation using the Kaufman Assessment Battery for Children (K-ABC). Subjects included 10 males with fragile X syndrome, 10 with Down syndrome, and 10 with nonspecific mental retardation who were equated on both mental and chronological age. Across all three groups, sequential processing was lower than simultaneous processing or achievement, and particular subtests (e.g., Gestalt Closure) were relative strengths. Although boys with Down syndrome showed less extreme patterns of domain strengths and weaknesses, they showed a significant strength in the Sequential Processing Hand Movements subtest. In contrast, the Hand Movements subtest was lowest of all K-ABC subtests for males with fragile X syndrome. Implications were discussed for more fine-tuned research and intervention efforts.

Autistic social dysfunction: some limitations of the theory of mind hypothesis.

This study examined the extent to which the social disabilities found in autism can be accounted for by the "Theory of Mind" hypothesis. Items related to social development from the Vineland Adaptive Behavior Scales were administered to 29 CA-, MA- and IQ-matched pairs of young autistic and non-autistic, developmentally disabled children. These items were evaluated in relation to expected ages of acquisition based on the Vineland standardization database. Our results indicate that the social dysfunction in autism affects very basic and early emerging social behaviors which are typically present prior to the time at which even the earliest precursors of a theory of mind apparently emerge.

Establishing the reliability and validity of neuropsychological disorders with low base rates: some recommended guidelines.

The issues of low prevalence in the context of the diagnosis of neuropsychological disorders in the larger community is discussed. Guidelines are proposed for producing reliability and validity estimates which are clinically, as well as statistically meaningful.

Childhood comorbidity of anxiety/affective disorders and behavior disorders.

Considerable data have been reported concerning comorbidity of various individual psychiatric disorders in children within the diagnostic supradomains of affect/anxiety disorders and behavior disorders as well as between these supradomains. To further examine such comorbidity, 35 psychiatrically hospitalized children were studied in terms of the prevalence of comorbidity, demographic and cognitive characteristics, adaptive functioning and maladaptive behaviors. The prevalence of comorbid behavior + affect/anxiety disorders exceeded 50% of the samples. Children with such comorbidity were similar to children with Behavior only diagnoses in terms of demographic and cognitive characteristics but differed in terms of adaptive functioning and maladaptive behaviors.

Facial perception in autism.

Disturbances in gaze and patterns of facial interaction are prominent aspects of social dysfunction in autism; the nature of this disturbance has up to the present been unclear. This study examined the ability of autistic subjects to use the human face as a source of information. Autistic and age- and MA-matched retarded control subjects assembled a series of puzzles displaying photographs of human faces; puzzles differed in complexity, familiarity of the faces and configuration (normal vs scrambled faces). Significant effects of all three factors, but not of diagnostic group, were observed. The autistic subjects did not exhibit specific deficits in perception of faces.

An evaluation of the Autism Behavior Checklist.

The Autism Behavior Checklist (ABC), an assessment instrument for autistic individuals, was evaluated in a group of 157 subjects, 94 clinically autistic and 63 nonautistic. The two groups differed significantly in ratings of pathology. Both false positive and false negative diagnostic classifications were made when the results of the checklist were compared with clinical diagnosis. Effects of developmental level and age were observed. The ABC appears to have merit as a screening instrument, though results of the checklist alone cannot be taken as establishing a diagnosis of autism. Important issues of reliability and validity remain to be addressed.

False conclusions about Vineland standard scores: Silverstein's type I errors and other artifacts.

Silverstein expressed concern that Vineland means and standard deviations (SDs) vary considerably from age group to age group in the national standardization sample. He concluded that as a result the following assessments are compromised: standard errors of measurement, domain strengths and weaknesses, and domain pairwise comparisons. This reply serves to document that Silverstein's reasoning is invalid and is directly attributable to his inexplicable failure to control for Type I error in his comparing 61 sample means and 61 sample SDs to population values of 100 and 15, respectively. Vineland users are cautioned to disregard caveats that are based upon flawed reasoning and invalid biostatistical arguments.