The discriminative ability and diagnostic utility of the ADOS-G, ADI-R, and GARS for children in a clinical setting

Comparison of saliva collection methods in children with high-functioning autism spectrum disorders: acceptability and recovery of cortisol

This study compared cortisol concentrations yielded using three saliva collection methods (passive drool, salivette, and sorbette) in both in vitro and in vivo conditions, as well as method acceptability for a sample of children (n = 39) with High Functioning Autism Spectrum Disorders. No cortisol concentration differences were observed between passive and sorbette samples obtained in vitro or in vivo. The salivette derived concentration was lower than the other two methods for the in vitro derived comparisons but did not differ from the other methods when collected in vivo. Cross-day comparison for the salivettes was also found to differ significantly, whereas the cross-day comparisons did not differ for the passive method or the sorbette method. Overall, passive drool and sorbettes were found to produce similar and stable readings of cortisol, whereas the salivette yielded unstable and variable concentrations. Ratings suggested that the children generally perceived all methods as acceptable.

Nosology and epidemiology in autism: classification counts

Since its initial description by Kanner in 1943, the criteria by which a diagnosis of autism or autism-like disorders was made--and their alleged etiologies portrayed--have undergone manifold changes, from a psychiatric disorder engendered by "refridgerator" parents to a neurodevelopmental disability produced in the main by genetic abnormalities. In addition, the behavioral characterization of autism has also entered the public consciousness and professional domains increasingly in the past 30 years, the effects of which we are continually coming to terms. A diagnosis of autism that once seemed quite unusual is now considered almost epidemic. Increasing numbers of individuals diagnosed with autism and related pervasive developmental disabilities will, in turn, affect the calculated prevalence of the disorder. In this essay, I attempt to account for the increasing prevalence of autism and autism-related disorders by examining its changing criteria, the individuals and instruments used to make the diagnosis, the reliability and validity of same, and the sample sizes and other aspects of the methodology needed to make an accurate estimate of its prevalence.

Multivariate searchlight classification of structural magnetic resonance imaging in children and adolescents with autism

BACKGROUND

Autism spectrum disorders (ASD) are neurodevelopmental disorders with a prevalence of nearly 1:100. Structural imaging studies point to disruptions in multiple brain areas, yet the precise neuroanatomical nature of these disruptions remains unclear. Characterization of brain structural differences in children with ASD is critical for development of biomarkers that may eventually be used to improve diagnosis and monitor response to treatment.

METHODS

We use voxel-based morphometry along with a novel multivariate pattern analysis approach and searchlight algorithm to classify structural magnetic resonance imaging data acquired from 24 children and adolescents with autism and 24 age-, gender-, and IQ-matched neurotypical participants.

RESULTS

Despite modest voxel-based morphometry differences, multivariate pattern analysis revealed that the groups could be distinguished with accuracies of approximately 90% based on gray matter in the posterior cingulate cortex, medial prefrontal cortex, and bilateral medial temporal lobes-regions within the default mode network. Abnormalities in the posterior cingulate cortex were associated with impaired Autism Diagnostic Interview communication scores. Gray matter in additional prefrontal, lateral temporal, and subcortical structures also discriminated between groups with accuracies between 81% and 90%. White matter in the inferior fronto-occipital and superior longitudinal fasciculi, and the genu and splenium of the corpus callosum, achieved up to 85% classification accuracy.

CONCLUSIONS

Multiple brain regions, including those belonging to the default mode network, exhibit aberrant structural organization in children with autism. Brain-based biomarkers derived from structural magnetic resonance imaging data may contribute to identification of the neuroanatomical basis of symptom heterogeneity and to the development of targeted early interventions.

No association between a common single nucleotide polymorphism, rs4141463, in the MACROD2 gene and autism spectrum disorder

The Autism Genome Project (AGP) Consortium recently reported genome-wide significant association between autism and an intronic single nucleotide polymorphism marker, rs4141463, within the MACROD2 gene. In the present study we attempted to replicate this finding using an independent case-control design of 1,170 cases with autism spectrum disorder (ASD) (874 of which fulfilled narrow criteria for Autism (A)) from five centers within Europe (UK, Germany, the Netherlands, Italy, and Iceland), and 35,307 controls. The combined sample size gave us a non-centrality parameter (NCP) of 11.9, with 93% power to detect allelic association of rs4141463 at an alpha of 0.05 with odds ratio of 0.84 (the best odds ratio estimate of the AGP Consortium data), and for the narrow diagnosis of autism, an NCP of 8.9 and power of 85%. Our case-control data were analyzed for association, stratified by each center, and the summary statistics were combined using the meta-analysis program, GWAMA. This resulted in an odds ratio (OR) of 1.03 (95% CI 0.944-1.133), with a P-value of 0.5 for ASD and OR of 0.99 (95% CI 0.88-1.11) with P-value = 0.85 for the Autism (A) sub-group. Therefore, this study does not provide support for the reported association between rs4141463 and autism.

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.

Anxiety and depression in children with HFASDs: symptom levels and source differences

The purpose of this study was to: (1) examine symptom levels of anxiety and depression in children with high-functioning autism spectrum disorders (HFASDs) compared with matched control children using child self-reports and parent ratings; and (2) examine source differences within the two condition groups. An overall multivariate effect indicated significantly elevated depression and anxiety symptoms for children with HFASDs based on parent reports; however no significant between-group differences based on child self-reports. Within-condition source comparisons (parent vs. child) revealed a significant multivariate effect indicating a significant difference in symptoms of depression and anxiety for the HFASD group but none for the control. Correlations between parent and child reports for the HFASD group suggested some positive association between child-reports and parent-reports for depressive symptoms only; however, the difference in average scores reflected a substantial discrepancy in the magnitude of symptoms by rater. Implications for clinical assessment and future research are provided.

Screening accuracy of Level 2 autism spectrum disorder rating scales. A review of selected instruments

The goal of this review was to examine the state of Level 2, caregiver-completed rating scales for the screening of Autism Spectrum Disorders (ASDs) in individuals above the age of three years. We focused on screening accuracy and paid particular attention to comparison groups. Inclusion criteria required that scales be developed post ICD-10, be ASD-specific, and have published evidence of diagnostic validity in peer-reviewed journals. The five scales reviewed were: the Social Communication Questionnaire (SCQ), Gilliam Autism Rating Scale/Gilliam Autism Rating Scale-Second Edition (GARS/GARS-2), Social Responsiveness Scale (SRS), Autism Spectrum Screening Questionnaire (ASSQ), and Asperger Syndrome Diagnostic Scale (ASDS). Twenty total studies were located, most examining the SCQ. Research on the other scales was limited. Comparisons between scales were few and available evidence of diagnostic validity is scarce for certain subpopulations (e.g., lower functioning individuals, PDDNOS). Overall, the SCQ performed well, the SRS and ASSQ showed promise, and the GARS/GARS-2 and ASDS demonstrated poor sensitivity. This review indicates that Level 2 ASD caregiver-completed rating scales are in need of much more scientific scrutiny.

Brief report: validity of Finnish registry-based diagnoses of autism with the ADI-R

AIMS

The aim of the study was to explore the validity of registry-based diagnoses of autism in Finland using the Autism Diagnostic Interview - Revised (ADI-R). This study was designed for the Finnish Prenatal Study of Autism and Autism Spectrum Disorders (FIPS-A), an ongoing research project where registry-based diagnoses will be used for epidemiological studies.

METHODS

In this small pilot study, a clinical sample of 95 subjects diagnosed with childhood autism or pervasive developmental disorder/pervasive developmental disorder - not otherwise specified (PDD/PDD-NOS) or Asperger's syndrome according to the Finnish Hospital Discharge Register (FHDR) was gathered nationwide. A small control group consisting of siblings without any registered diagnoses of those being examined was also included in the study. Diagnoses were further re-evaluated by interviewing parents with the ADI-R.

RESULTS

The mean scores of autistic subjects clearly exceeded cut-off limits for autism on all three ADI-R domains and 96% of the subjects with registered diagnosis of childhood autism fulfilled the criteria based on the instrument as well.

CONCLUSION

These results suggest that the validity of Finnish registry-based diagnoses of childhood autism can be considered good. Our findings lay important groundwork for further population- based studies of the aetiology of autism.

No evidence for impaired perception of biological motion in adults with autistic spectrum disorders

A central feature of autistic spectrum disorders (ASDs) is a difficulty in identifying and reading human expressions, including those present in the moving human form. One previous study, by Blake et al. (2003), reports decreased sensitivity for perceiving biological motion in children with autism, suggesting that perceptual anomalies underlie problems in social cognition. We revisited this issue using a novel psychophysical task. 16 adults with ASDs and 16 controls were asked to detect the direction of movement of human point-light walkers which were presented in both normal and spatially scrambled forms in a background of noise. Unlike convention direction discrimination tasks, in which walkers walk 'on the spot' while facing left or right, we added translatory motion to the stimulus so that the walkers physically moved across the screen. Therefore, while a cue of coherent, translatory motion was available in both the normal and scrambled walker forms, the normal walker alone contained information about the configuration and kinematics of the human body. There was a significant effect of walker type, with reduced response times and error when the normal walker was present. Most importantly, these improvements were the same for both participant groups, suggesting that people with ASDs do not have difficulty integrating local visual information into a global percept of the moving human form. The discrepancy between these and previous findings of impaired biological motion perception in ASDs are discussed with reference to differences in the age and diagnosis of the participants, and the nature of the task.

Genes controlling affiliative behavior as candidate genes for autism

BACKGROUND

Autism spectrum disorders (ASD) are neurodevelopmental disorders of complex etiology, with a recognized substantial contribution of heterogeneous genetic factors; one of the core features of ASD is a lack of affiliative behaviors.

METHODS

On the basis of the existing literature, in this study we examined the hypothesis of allelic associations between genetic variants in six genes involved in control of maternal and affiliative behaviors (OXT, OXTR, PRL, PRLR, DbetaH, and FOSB). One hundred and seventy-seven probands with ASD from 151 families (n = 527) were assessed with a set of related instruments capturing multiple facets of ASD. Multivariate and univariate phenotypes were constructed from these assessments and subjected to genetic linkage and association analyses with PBAT and FBAT software.

RESULTS

The resulting pattern of findings, in general, confirmed the hypotheses of the significance of the genes involved in the development of affiliative behaviors in the manifestation of ASD (p values ranging from .000005 to .05); statistically speaking, the strongest results were obtained for allelic associations with the PRL, PRLR, and OXTR genes.

CONCLUSIONS

These preliminary data provide additional support for the hypothesis that the allelic variants of genes necessary for the development of species-typical affiliative behaviors are associated with ASD. Independent replication of these findings is needed and studies of other genes associated with affiliative behaviors are indicated.

A comprehensive approach to treating autism and attention-deficit hyperactivity disorder: a prepilot study

OBJECTIVES

The purpose of this study was to observe the effects of a multi dimensional treatment plan involving nutrition, environmental control, chelation, and behavioral/educational/physical/speech therapy to treat children with autistic spectrum disorder and attention-deficit hyperactivity (ADHD) disorder. This study is only a preliminary study, and its small size (10 patients) precludes statistical analysis of simultaneous multiple modal treatment regimes.

DESIGN

This was an open-label observational study. SETTINGS/LOCATION/SUBJECTS: This study examined 10 children aged 4-10 years old who had been diagnosed with both autistic spectrum disorder and ADHD by outside physicians or psychologists. These 10 children presented consecutively in an environmental medicine clinic in Buffalo, New York. The children were given comprehensive nutritional/environmental/chelation treatment for 3 to 6 months in addition to their usual behavioral, educational, speech, and physical therapies.

OUTCOME MEASURES

Study outcomes were measured by objective/subjective improvement as judged by physicians/parents/teachers. Outcomes were also measured by changes in urinary heavy metal burdens over time.

RESULTS

All 10 children showed significant improvement in many areas of social interaction, concentration, writing, language, and behavior. Urinary lead burden dropped significantly in all 10 children.

CONCLUSIONS

Autistic spectrum disorders and ADHD are complicated conditions that probably require multidimensional treatment strategies. Larger studies are needed to determine optimum treatment plans involving nutrition, environmental control, medication, and behavioral/education/speech/physical therapies.

Comparison of form and motion coherence processing in autistic spectrum disorders and dyslexia

A large body of research has reported visual perception deficits in both people with dyslexia and autistic spectrum disorders. In this study, we compared form and motion coherence detection between a group of adults with high-functioning autism, a group with Asperger's disorder, a group with dyslexia, and a matched control group. It was found that motion detection was intact in dyslexia and Asperger. Individuals with high-functioning autism showed a general impaired ability to detect coherent form and motion. Participants with Asperger's syndrome showed lower form coherence thresholds than the dyslexic and normally developing adults. The results are discussed with respect to the involvement of the dorsal and ventral pathways in developmental disorders.

Diagnosing autism spectrum disorders in pre-school children using two standardised assessment instruments: the ADI-R and the ADOS

The reliable diagnosis of Autism/Autism Spectrum Disorder in pre-school children is important for access to early intervention and for accurate ascertainment for research. This paper explores the combined use of two standardised assessment instruments--the Autism Diagnostic Interview Revised (ADI-R) and the Autism Diagnostic Observation Schedule (ADOS)--in a large sample of pre-school children. The children were recruited to research studies, and a 'best estimate' clinical diagnosis reached. The findings show good agreement between the instruments especially for children with core Autism. The instruments appear to have a complementary effect in aiding diagnosis and confirm the importance of a multidisciplinary assessment process with access to information from different sources and settings. The presence of repetitive behaviours during the ADOS appeared of diagnostic significance.