A replication of the Autism Diagnostic Observation Schedule (ADOS) revised algorithms

Social communication and theory of mind in boys with autism and fragile x syndrome

Impairments in the social use of language, or pragmatics, constitute a core characteristic of autism. Problems with pragmatic language have also been documented in fragile X syndrome (FXS), a monogenic condition that is the most common known genetic cause of autism. Evidence suggests that social cognitive ability, or theory of mind, may also be impaired in both conditions, and in autism, may importantly relate to pragmatic language ability. Given the substantial overlap observed in autism and FXS, this study aimed to better define those social-communicative phenotypes that overlap in these two conditions by comparing pragmatic language ability and theory of mind in children with idiopathic autism and children with FXS, with and without autism, as well as children with Down syndrome and typically developing controls. We further examined correlations between these cognitive-behavioral phenotypes and molecular genetic variation related to the Fragile X Mental Retardation-1 gene (FMR1) in the FXS group. Results indicated that children with idiopathic autism and those with FXS and autism performed comparably on direct-assessment measures of pragmatic language and theory of mind, whereas those with FXS only did not differ from controls. Theory of mind was related to pragmatic language ability in all groups. Pragmatic language and theory of mind also correlated with genetic variation at the FMR1 locus (Cytosine-Guanine-Guanine repeats and percent methylation). These results point toward substantial overlap in the social and language phenotypes in autism and FXS and suggest a molecular genetic basis to these phenotypic profiles.

The ADOS calibrated severity score: relationship to phenotypic variables and stability over time

Measurement of the severity of autism at a single time point, and over time, is a widespread challenge for researchers. Recently, Gotham, Pickles, and Lord published a severity metric (calibrated severity scores; CSS) that takes into account age and language level and is based on raw total scores of the Autism Diagnostic Observation Schedule (ADOS), a standardized measure commonly used in autism diagnosis. The present study examined psychometric characteristics of the CSS compared to raw scores in an independent sample of 368 children aged 2 to 12 years with autism, pervasive developmental disorder-not otherwise specified (PDD-NOS), non-spectrum delay, or typical development. Reflecting the intended calibration, the CSS were more uniformly distributed within clinical diagnostic category and across ADOS modules than were raw scores. Cross-sectional analyses examining raw and severity scores and their relationships to participant characteristics revealed that verbal developmental level was a significant predictor of raw score but accounted for significantly less variance in the CSS. Longitudinal analyses indicated overall stability of the CSS over 12 to 24 months in children with autism. Findings from this study support the use of the CSS as a more valid indicator of autism severity than the ADOS raw total score, and extend the literature by examining the stability over 12 to 24 months of the CSS in children with ASD.

Measuring change in social interaction skills of young children with autism

Designing effective treatments for improving early social behaviors in autism has been identified as a critical research need. One barrier to drawing conclusions about optimal treatments for children with autism is the use of highly varied dependent measures in the treatment literature. Contributing to this is the absence of "gold standard" assessment batteries. This is particularly true for assessing changes in social interaction impairments in very young children with autism. This paper addresses this issue by reviewing variables important in the development and evaluation of assessment measures, discussing previous studies' choices of socially-related dependent measures, and the strengths, limitations, and research questions pertaining to them. It concludes with recommendations for measurement selection and future directions for research.

Annual research review: re-thinking the classification of autism spectrum disorders

BACKGROUND

The nosology of autism spectrum disorders (ASD) is at a critical point in history as the field seeks to better define dimensions of social-communication deficits and restricted/repetitive behaviors on an individual level for both clinical and neurobiological purposes. These different dimensions also suggest an increasing need for quantitative measures that accurately map their differences, independent of developmental factors such as age, language level and IQ.

METHOD

Psychometric measures, clinical observation as well as genetic, neurobiological and physiological research from toddlers, children and adults with ASD are reviewed.

RESULTS

The question of how to conceptualize ASDs along dimensions versus categories is discussed within the nosology of autism and the proposed changes to the DSM-5 and ICD-11. Differences across development are incorporated into the new classification frameworks.

CONCLUSIONS

It is crucial to balance the needs of clinical practice in ASD diagnostic systems, with neurobiologically based theories that address the associations between social-communication and restricted/repetitive dimensions in individuals. Clarifying terminology, improving description of the core features of ASD and other dimensions that interact with them and providing more valid and reliable ways to quantify them, both for research and clinical purposes, will move forward both practice and science.

Morphological and syntactic skills in language samples of pre school aged children with autism: atypical development?

This study investigated whether children with autism have atypical development of morphological and syntactic skills, including whether they use rote learning to compensate for impaired morphological processing and acquire grammatical morphemes in an atypical order. Participants were children aged from 3-6 years who had autism (n = 17), developmental delay without autism (n = 7), and typically-developing children (n = 19). Language samples were taken from participants during the administration of the Autism Diagnostic Observation Schedule, and transcripts were coded using the Index of Productive Syntax, and for usage of Brown's grammatical morphemes. Participants were also administered an elicitation task requiring the application of inflections to non-words; the Wugs Task. The main finding of this study was that children with autism have unevenly developed morphological and syntactic sub-skills; they have skills which are a combination of intact, delayed, and atypical. It was also found that children with autism and children with developmental delays can acquire and use morphological rules. The implications of these findings are that, in order to maximize language acquisition for these children, clinicians need to utilize comprehensive language assessment tools and design interventions that are tailored to the child's strengths and weaknesses.

Longitudinal follow-up of autism spectrum features and sensory behaviors in Angelman syndrome by deletion class

BACKGROUND

Angelman syndrome (AS) is a neurogenetic disorder characterized by severe intellectual disability, lack of speech, and low threshold for laughter; it is considered a 'syndromic' form of autism spectrum disorder (ASD). Previous studies have indicated overlap of ASD and AS, primarily in individuals with larger (∼6 Mb) Class I deletions of chromosome 15q11-13. Questions remain regarding whether intellectual disability solely contributes to ASD features in AS and how ASD features in AS change over time. In this study, we used a dimensional approach to examine ASD symptom severity in individuals with AS Class I versus Class II deletions within the context of cognitive development over time.

METHODS

A total of 17 participants with a larger, Class I deletion and 25 participants with a smaller Class II deletion (∼5 Mb) were enrolled (age range = 2-25 years; 5 years 5 months). Standardized measures of cognition, language, motor skills, adaptive skills, maladaptive behavior, autism, and sensory-seeking behaviors/aversions were given at baseline and after 12 months.

RESULTS

Despite equivalent cognition and adaptive behavior, the results of repeated measures analyses of variance indicate that participants with Class I deletions have greater impairment in social affect (F = 8.65; p = .006) and more repetitive behaviors (F = 7.92; p = .008) compared to participants with Class II deletions. Although both groups improve in cognition over time, differences in ASD behaviors persist.

CONCLUSIONS

Despite a lack of differences in cognition or adaptive behavior, individuals with Class I deletions have greater severity in ASD features and sensory aversions that remain over time. There are four genes (NIPA 1, NIPA 2, CYFIP1, and GCP5) missing in Class I and present in Class Il deletions, one or more of which may have a role in modifying the severity of social affect impairment, and level of restricted/repetitive behaviors in AS. Our results also suggest the utility of a dimensional, longitudinal approach to the assessment of ASD features in populations of individuals who are low functioning.

Profiles of receptive and expressive language abilities in boys with comorbid fragile X syndrome and autism

Abstract The authors examined receptive and expressive language profiles for a group of verbal male children and adolescents who had fragile X syndrome along with varying degrees of autism symptoms. A categorical approach for assigning autism diagnostic classification, based on the combined use of the Autism Diagnostic Interview-Revised and the Autism Diagnostic Observation Schedule (ADOS), and a continuous approach for representing autism symptom severity, based on ADOS severity scores, were used in 2 separate sets of analyses. All analyses controlled for nonverbal IQ and chronological age. Nonverbal IQ accounted for significant variance in all language outcomes with large effect sizes. Results of the categorical analyses failed to reveal an effect of diagnostic group (fragile X syndrome-autism, fragile X syndrome-no autism) on standardized language test performance. Results of the continuous analyses revealed a negative relationship between autism symptom severity and all of the standardized language measures. Implications for representing autism symptoms in fragile X syndrome research are considered.

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.

Autism: from research to practice

Autism is the most commonly studied of a spectrum of developmental disorders that are believed to be neurobiologically based but which, at this point, for lack of good biomarkers, are defined purely by behavior. In the last 20 years, the definition of autism has shifted in emphasis from extreme aloofness and positive signs of abnormality in repetitive and sensorimotor behaviors to a greater awareness of the importance of more subtle reciprocal social communication deficits as core features. Standard diagnostic instruments were developed for research purposes to acquire information both through caregiver interviews and direct clinical observation. Use of these instruments in clinical practice resulted in major improvements, which in turn affected research results. These results yielded further improvements that led to changes in clinical practice over time. The synergism between research and clinical practice in the understanding of autism is discussed.

Advanced parental ages and low birth weight in autism spectrum disorders--rates and effect on functioning

OBJECTIVES

(1) To assess the distribution of parental age and birth weight in a large cohort with autism spectrum disorder (ASD) and to compare them to Israeli national data. (2) To examine possible relationships between these risk factors and functioning.

METHODS

The study included 529 participants diagnosed with ASD using standardized tests: the Autism Diagnosis Interview-Revised and the Autism Diagnosis Observation Schedule (ADOS). Medical, developmental and familial histories (gender, age, pregnancy and birth information, parental ages) were obtained. Autism severity was assessed using the new ADOS severity scale and adaptive skill using the Vineland Adaptive Behavior Scales.

RESULTS

Advanced parental age was associated with ASD. In the older age range the percentages of mothers (35-44 y) and fathers (30-40 y) were significantly higher in the ASD cohort in comparison to the Israeli newborn data. The ASD cohort had significantly higher percentages of low birth weight (<2500 g) and very low birth weight (VLBW<1500 g) in comparison to the Israeli newborn data. Of these risk factors, only VLBW was associated with lower adaptive functioning. The group with VLBW had lower scores in daily living, socialization and motor skills in comparison to the >1500 g group. Autism severity was not associated with advanced parental age or VLBW.

CONCLUSIONS

The shift in parental age distribution and birth weight in our ASD cohort suggests that the increase in ASD prevalence in recent years might be associated with novel prenatal insults. An adverse fetal course resulting in VLBW may represent a "second hit" phenomenon, causing a poorer outcome.

Diagnosing autism spectrum disorders in adults: the use of Autism Diagnostic Observation Schedule (ADOS) module 4

Autism Diagnostic Observation Schedule (ADOS) module 4 was investigated in an independent sample of high-functioning adult males with an autism spectrum disorder (ASD) compared to three specific diagnostic groups: schizophrenia, psychopathy, and typical development. ADOS module 4 proves to be a reliable instrument with good predictive value. It can adequately discriminate ASD from psychopathy and typical development, but is less specific with respect to schizophrenia due to behavioral overlap between autistic and negative symptoms. However, these groups differ on some core items and explorative analyses indicate that a revision of the algorithm in line with Gotham et al. (J Autism Dev Disord 37: 613-627, 2007) could be beneficial for discriminating ASD from schizophrenia.

Standardized ADOS scores: measuring severity of autism spectrum disorders in a Dutch sample

The validity of the calibrated severity scores on the ADOS as reported by Gotham et al. (J Autism Dev Disord 39: 693–705, 2009), was investigated in an independent sample of 1248 Dutch children with 1455 ADOS administrations (modules 1, 2 and 3). The greater comparability between ADOS administrations at different times, ages and in different modules, as reached by Gotham et al. with the calibrated severity measures, seems to be corroborated by the current study for module 1 and to a lesser extent for module 3. For module 2, the calibrated severity scores need to be further investigated within a sample that resembles Gotham’s sample in age and level of verbal functioning.

Eye-tracking as a Measure of Responsiveness to Joint Attention in Infants at Risk for Autism

Reduced responsiveness to joint attention (RJA), as assessed by the Early Social Communication Scales (ESCS), is predictive of both subsequent language difficulties and autism diagnosis. Eye-tracking measurement of RJA is a promising prognostic tool because it is highly precise and standardized. However, the construct validity of eye-tracking assessments of RJA has not been established. By comparing RJA in an eye-tracking paradigm to RJA during the ESCS, the current study evaluated the construct validity of an eye-tracking assessment of RJA for 18-month-old infant siblings of children with autism. Relations between measures of RJA and concurrent language skills and autistic symptomatology were assessed. Correlations between measures of ESCS RJA and eye-tracking RJA were statistically significant, but few relations between either ESCS or eye-tracking assessments of RJA and language or symptoms were observed. This study establishes the construct validity of eye-tracking assessments of RJA.

Evaluation of the revised algorithm of Autism Diagnostic Observation Schedule (ADOS) in the diagnostic investigation of high-functioning children and adolescents with autism spectrum disorders

The Autism Diagnostic Observation Schedule (ADOS) is a semi-structured, standardized assessment designed for use in diagnostic evaluation of individuals with suspected autism spectrum disorder (ASD). The ADOS has been effective in categorizing children who definitely have autism or not, but has lower specificity and sometimes sensitivity for distinguishing children with milder ASDs. Revised ADOS algorithms have been recently developed. The goals of this study were to analyze the predictive validity of different ADOS algorithms for module 3, in particular for high-functioning autism spectrum disorder. The participants were 252 children and adolescents aged between four and 16 years, with a full-scale IQ above 70 (126 with a diagnosis of ASD, 126 with a heterogeneous non-spectrum diagnosis). As a main finding, sensitivity was substantially higher for the newly developed 'revised algorithm', both for autism versus non-spectrum, as well as for the broader ASD versus non-spectrum, using the higher cut-off. The strength of the original algorithm lies in its positive predictive power, while the revised algorithm shows weaknesses in specificity for non-autism ASD. As the ADOS is valid and reliable even for higher functioning ASD, the findings of the present study have been used to make recommendations regarding the best use of ADOS algorithms in a high-functioning sample.

Autistic traits and autism spectrum disorders: the clinical validity of two measures presuming a continuum of social communication skills

Research indicates that autism is the extreme end of a continuously distributed trait. The Social Responsiveness Scale (SRS) and the Social and Communication Disorders Checklist (SCDC) aim to assess autistic traits. The objective of this study was to compare their clinical validity. The SRS showed sensitivities of .74 to .80 and specificities of .69 to 1.00 for autism. Sensitivities were .85 to .90 and specificities .28 to.82 for the SCDC. Correlations with the ADI-R, ADOS and SCQ were higher for the SRS than for the SCDC. The SCDC seems superior to the SRS to screen for unspecific social and communicative deficits including autism. The SRS appears more suitable than the SCDC in clinical settings and for specific autism screening.

Assessment of behavioral disorders in preschool-aged children

The preschool-aged clinical practice of child and adolescent psychiatrists is increasing as the awareness of very young children with social/emotional and/or behavioral problems continues to grow. As the referrals grow, so do the ways in which we assess these disturbances of behavior and regulation. This review attempts to highlight the most often used measures and to investigate developing tools and their current status.

A proposed mechanism for autism: an aberrant neuroimmune response manifested as a psychiatric disorder

Autism, an incurable neurodevelopmental brain disorder, is a complex psychopathology in which the affected individual cannot effectively self-regulate their sensory inputs toward coherent and focused motor outputs. There have been many hypotheses as to the etiology of autism - genetics, neurotransmitter imbalances, early childhood immunizations, xenobiotic and teratogenic agents, and maternal infection; the disorder can perhaps be studied best under the field of "Psychoneuroimmunology", which analyzes systemic and psychopathologies from an integrated approach through the combined effects of the nervous, immune, and endocrine systems. Using principles of psychoneuroimmunology along with previously established but yet un-linked scientific principles and observations, this paper proposes a neuroimmune-based mechanistic hypothesis for the etiology of autism that connects elevated levels of maternal pro-inflammatory cytokines to autistic symptoms in her offspring through a logical sequence of events. While both researchers and clinicians often note correlations between pro-inflammatory cytokine levels and autistic symptoms in affected individuals, no specific mechanism has been documented that logically and directly connects the two. I propose that pro-inflammatory cytokines arising from maternal inflammation, infection, and, possibly, autoimmunity, pass through the placenta; enter the fetal circulation; cross the fetal blood-brain barrier (BBB); and cause aberrant neuronal growth and plasticity within the fetal brain via a "cytokine-storm". Microglia and astrocyte stimulation lead to a positive-feedback loop that also facilitates the development of a chronic inflammatory environment within the fetus, pre-disposing it to lifelong comorbid psychiatric and systemic pathologies. Such a mechanism could account for many of the observed symptoms and behaviors of autistic individuals such as hyper-sensitivity to environmental stimuli, object fixation, echolalia, repetitive physical behaviors, chronic enterocolitis, autoimmune disease, and, at the extreme, savantism. The thiazolidinedione pioglitazone (and possibly rosiglitazone), a non-steroidal anti-inflammatory drug (NSAID), which is commonly used to lower blood glucose levels and associated inflammatory markers in patients with diabetes, and histamine receptor blockers, as well as monitoring and limiting sucrose-containing foods, might prove to be effective preventative therapies for the development of autism in the fetus for pregnant women displaying either a cytokine-induced depression or other elevated systemic inflammatory state conditions.

Use of the Autism Diagnostic Observation Schedule (ADOS) in a clinical setting

The aim of this study was to examine the Autism Diagnostic Observation Schedule (ADOS) as it is commonly used in clinical practice. ADOS classifications were compared to final diagnoses given by a multidisciplinary team to 584 children referred for evaluation for possible autism spectrum disorder (ASD) at the Cincinnati Children’s Hospital Medical Center. A total of 177 children were evaluated with a Module 1 (87 No Words), 198 with a Module 2 (90 < 5 years) and 209 with a Module 3. Of these, 142 (26%) were diagnosed with autism, 185 (32%) with non-autism ASD, and 257 (44%) with non-spectrum disorders. Sensitivities were moderate to high on both original and revised algorithms, while specificities were substantially lower than those previously reported. This difference is likely attributable to the composition of the sample that included many children with a broad array of developmental and behavioral disorders. The clinical impression of the team member who administered the ADOS was critical to the accuracy of the overall diagnosis. Using numeric scores alone resulted in misclassification from false positive results. The study highlights the importance of the qualitative interactions of the ADOS activities as well as the score in diagnostic decision making.

Computational prosodic markers for autism

We present results obtained with new instrumental methods for the acoustic analysis of prosody to evaluate prosody production by children with Autism Spectrum Disorder (ASD) and Typical Development (TD). Two tasks elicit focal stress - one in a vocal imitation paradigm, the other in a picture-description paradigm; a third task also uses a vocal imitation paradigm, and requires repeating stress patterns of two-syllable nonsense words. The instrumental methods differentiated significantly between the ASD and TD groups in all but the focal stress imitation task. The methods also showed smaller differences in the two vocal imitation tasks than in the picture-description task, as was predicted. In fact, in the nonsense word stress repetition task, the instrumental methods showed better performance for the ASD group. The methods also revealed that the acoustic features that predict auditory-perceptual judgment are not the same as those that differentiate between groups. Specifically, a key difference between the groups appears to be a difference in the balance between the various prosodic cues, such as pitch, amplitude, and duration, and not necessarily a difference in the strength or clarity with which prosodic contrasts are expressed.

Improved diagnostic validity of the ADOS revised algorithms: a replication study in an independent sample

Recently, Gotham et al. (2007) proposed revised algorithms for the Autism Diagnostic Observation Schedule (ADOS) with improved diagnostic validity. The aim of the current study was to replicate predictive validity, factor structure, and correlations with age and verbal and nonverbal IQ of the ADOS revised algorithms for Modules 1 and 2 in a large independent Dutch sample (N = 532). Results showed that the improvement of diagnostic validity was most apparent for autism, except in very young or low functioning children. Results for other autism spectrum disorders were less consistent. Overall, these findings support the use of the more homogeneous revised algorithms, with the use of similar items across developmental cells making it easier to compare ADOS scores within and between individuals.

Computational prosodic markers for autism

We present results obtained with new instrumental methods for the acoustic analysis of prosody to evaluate prosody production by children with Autism Spectrum Disorder (ASD) and Typical Development (TD). Two tasks elicit focal stress — one in a vocal imitation paradigm, the other in a picture-description paradigm; a third task also uses a vocal imitation paradigm, and requires repeating stress patterns of two-syllable nonsense words. The instrumental methods differentiated significantly between the ASD and TD groups in all but the focal stress imitation task. The methods also showed smaller differences in the two vocal imitation tasks than in the picture-description task, as was predicted. In fact, in the nonsense word stress repetition task, the instrumental methods showed better performance for the ASD group. The methods also revealed that the acoustic features that predict auditory-perceptual judgment are not the same as those that differentiate between groups. Specifically, a key difference between the groups appears to be a difference in the balance between the various prosodic cues, such as pitch, amplitude, and duration, and not necessarily a difference in the strength or clarity with which prosodic contrasts are expressed.

Developmental trajectories of restricted and repetitive behaviors and interests in children with autism spectrum disorders

This study examined how restricted and repetitive behaviors and interests (RRBs) developed over time in a sample of children with autism spectrum disorders (ASD). One hundred ninety-two children referred for a diagnosis of autism at age 2, and 22 children with nonspectrum development disorders were evaluated with a battery of cognitive and diagnostic measures at age 2 and subsequently at ages 3, 5, and 9. Factor analysis of the RRB items on the Autism Diagnostic Interview-Revised revealed two RRB factors at each wave of data collection, one comprising "repetitive sensorimotor" (RSM) behaviors and the other "insistence on sameness" (IS) behaviors. For children with ASD, RSM scores remained relatively high over time, indicating consistent severity, whereas IS scores started low and increased over time, indicating worsening. Having a higher nonverbal intelligence (NVIQ) at age 2 was associated with milder concurrent RSM behaviors and with improvement in these behaviors over time. There was no relationship between NVIQ at age 2 and IS behaviors. However, milder social/communicative impairment, at age 2 was associated with more severe concurrent IS behaviors. Trajectory analysis revealed considerable heterogeneity in patterns of change over time for both kinds of behaviors. These findings are discussed in terms of their implications for our understanding of RRBs in ASD and other disorders, making prognoses about how RRBs will develop in children with ASD as they get older, and using RRBs to identify ASD phenotypes in genetic studies.

Automated Assessment of Prosody Production

Assessment of prosody is important for diagnosis and remediation of speech and language disorders, for diagnosis of neurological conditions, and for foreign language instruction. Current assessment is largely auditory-perceptual, which has obvious drawbacks; however, automation of assessment faces numerous obstacles. We propose methods for automatically assessing production of lexical stress, focus, phrasing, pragmatic style, and vocal affect. Speech was analyzed from children in six tasks designed to elicit specific prosodic contrasts. The methods involve dynamic and global features, using spectral, fundamental frequency, and temporal information. The automatically computed scores were validated against mean scores from judges who, in all but one task, listened to "prosodic minimal pairs" of recordings, each pair containing two utterances from the same child with approximately the same phonemic material but differing on a specific prosodic dimension, such as stress. The judges identified the prosodic categories of the two utterances and rated the strength of their contrast. For almost all tasks, we found that the automated scores correlated with the mean scores approximately as well as the judges' individual scores. Real-time scores assigned during examination - as is fairly typical in speech assessment - correlated substantially less than the automated scores with the mean scores.

Autism spectrum disorders in infancy and toddlerhood: a review of the evidence on early signs, early identification tools, and early diagnosis

To date, the biological basis of autism spectrum disorders (ASDs) remains unknown. Thus, identification and diagnosis are reliant on behavioral presentation and developmental history. There have been significant advances in our knowledge of the early signs of ASD through the use of retrospective videotape analysis, parental report, screening studies, and more recently, studies on high-risk infant siblings. Despite behavioral markers being identified within the first year of life, the current average age of diagnosis for ASD remains at approximately 3 years or older. Consequently, these children are not receiving intervention in their early years, which is increasingly recognized as an important time to begin intervention. There remains little research on the prospective identification of these children in a community-based sample before 18 months. It is recommended that future prospective studies monitor behavior repeatedly over time, thereby increasing the opportunity to identify early manifestations of ASD and facilitating the charting of subtle behavioral changes that occur in the development of infants and toddlers with ASD.

Predicting social impairment and ASD diagnosis in younger siblings of children with autism spectrum disorder

Later-born siblings of children with autism spectrum disorder (Sibs-ASD) are at elevated risk for social impairments. Two putative predictors of later social impairment-measures of responding to joint attention and weighted triadic communication-were examined in a sample of 43 Sibs-ASD who were followed from 15 to 34 months of age. Results revealed that initial level of responding to joint attention and growth rate of weighted triadic communication predicted the degree of social impairment at the final measurement period. Additionally, both predictors were associated with later ASD diagnosis. In contrast, unweighted triadic communication, age of entry into the study, and initial language level did not predict later social impairment. The importance of considering social outcome as a continuous variable in prospective studies of Sibs-ASD is discussed.

The power and promise of identifying autism early: insights from the search for clinical and biological markers

BACKGROUND

The biological changes that lead to autism likely occur during prenatal life. Although earlier identification of the disorder has occurred within the past decade, the mean age of diagnosis is still not made before a mean age of 3 years. This is because autism remains a behaviorally defined disorder, placing limits on the age at which a confident diagnosis can be made. The study of the biological basis of autism prior to age 3 is essential and can most directly be achieved with prospective research designs.

METHODS

The literature on the early identification of autism is discussed, including the timescale for the onset of social symptoms. Also discussed is a new method for the prospective study of autism called the "1-Year Well-Baby Check-Up Approach," which allows for the prospective study of the disorder in simplex families with infants as young as 12 months of age.

RESULTS

Although likely present at subtle, subclinical levels, early social abnormalities are not clearly detectable prior to 12 months in age in infants later diagnosed as having autism spectrum disorder.

CONCLUSIONS

Using the 1-Year Well-Baby Check-Up Approach or other prospective design, examining early biomarkers related to early brain overgrowth, cerebellar development, gene expression patterns and immune system function may be key to early diagnosis efforts under 3 years. We also note the importance of comparing and contrasting the early "signature" of autism in children from singleton versus multiplex families, which may be etiologically distinct.

Evaluation of the ADOS revised algorithm: the applicability in 558 Dutch children and adolescents

The revised ADOS algorithms, proposed by Gotham et al. (J Autism Dev Disord 37:613–627, 2007), were investigated in an independent sample of 558 Dutch children (modules 1, 2 and 3). The revised algorithms lead to better balanced sensitivity and specificity for modules 2 and 3, without losing efficiency of the classification. Including the restricted repetitive behaviour domain in the algorithm contributes to a clinical ASD classification in modules 2 and 3. For module 1, the results indicate less improvement, probably due to the low-functioning population. In most groups, the advantages of the revised algorithms are achieved without losing the strength of the original algorithm.

The Autism Diagnostic Observation Schedule-toddler module: a new module of a standardized diagnostic measure for autism spectrum disorders

The Autism Diagnostic Observation Schedule (ADOS; Lord et al., J Autism Dev Disord, 30(3):205-223, 2000) is widely accepted as a "gold standard" diagnostic instrument, but it is of restricted utility with very young children. The purpose of the current project was to modify the ADOS for use in children under 30 months of age. A modified ADOS, the ADOS Toddler Module (or Module T), was used in 360 evaluations. Participants included 182 children with best estimate diagnoses of ASD, non-spectrum developmental delay or typical development. A final set of protocol and algorithm items was selected based on their ability to discriminate the diagnostic groups. The traditional algorithm "cutoffs" approach yielded high sensitivity and specificity, and a new range of concern approach was proposed.

Standardizing ADOS scores for a measure of severity in autism spectrum disorders

The aim of this study is to standardize Autism Diagnostic Observation Schedule (ADOS) scores within a large sample to approximate an autism severity metric. Using a dataset of 1,415 individuals aged 2-16 years with autism spectrum disorders (ASD) or nonspectrum diagnoses, a subset of 1,807 assessments from 1,118 individuals with ASD were divided into narrow age and language cells. Within each cell, severity scores were based on percentiles of raw totals corresponding to each ADOS diagnostic classification. Calibrated severity scores had more uniform distributions across developmental groups and were less influenced by participant demographics than raw totals. This metric should be useful in comparing assessments across modules and time, and identifying trajectories of autism severity for clinical, genetic, and neurobiological research.