Diagnosing autism in a clinical sample of adults with intellectual disabilities: how useful are the ADOS and the ADI-R?

Classifying autism in a clinical population based on motion synchrony: a proof-of-concept study using real-life diagnostic interviews

Predictive modeling strategies are increasingly studied as a means to overcome clinical bottlenecks in the diagnostic classification of autism spectrum disorder. However, while some findings are promising in the light of diagnostic marker research, many of these approaches lack the scalability for adequate and effective translation to everyday clinical practice. In this study, our aim was to explore the use of objective computer vision video analysis of real-world autism diagnostic interviews in a clinical sample of children and young individuals in the transition to adulthood to predict diagnosis. Specifically, we trained a support vector machine learning model on interpersonal synchrony data recorded in Autism Diagnostic Observation Schedule (ADOS-2) interviews of patient-clinician dyads. Our model was able to classify dyads involving an autistic patient (n = 56) with a balanced accuracy of 63.4% against dyads including a patient with other psychiatric diagnoses (n = 38). Further analyses revealed no significant associations between our classification metrics with clinical ratings. We argue that, given the above-chance performance of our classifier in a highly heterogeneous sample both in age and diagnosis, with few adjustments this highly scalable approach presents a viable route for future diagnostic marker research in autism.

Child characteristics associated with child quality of life and parenting stress in Angelman syndrome

BACKGROUND

Angelman syndrome (AS) is a rare neurodevelopmental disorder characterised by severe intellectual disability, movement disorder, epilepsy, sleeping problems, and behavioural issues. Little is known on child health-related quality of life (HRQoL) in AS. AS family studies have reported elevated parenting stress and a high impact of the child's syndrome on the parent. It is unclear which factors influence child HRQoL and parenting stress/impact in AS.

METHODS

We collected data prospectively through standardised clinical assessments of children with AS at the ENCORE Expertise centre for Angelman Syndrome at the Erasmus MC Sophia Children's Hospital. A linear regression analysis was conducted for the following outcome variables: (1) child HRQoL (Infant and Toddler Quality of Life Questionnaire); (2) the impact of the child's syndrome on the parent (Infant and Toddler Quality of Life Questionnaire); and (3) parenting stress (Parenting Stress Index). Predictor variables were child genotype, epilepsy, sleeping problems (Sleep Disturbance Scale for Children), cognitive developmental level (Bayley Cognition Scale), autistic features (Autism Diagnostic Observation Schedule) and emotional/behavioural problems (Child Behaviour Checklist). Covariates were sex, age and socio-economic status.

RESULTS

The study sample consisted of 73 children with AS, mean age = 9.1 years, range = 2-18 years. Emotional/behavioural problems were the strongest significant predictor of lowered child HRQoL. Internalising problems were driving this effect. In addition, having the deletion genotype and higher age was related to lower child HRQoL. Sleeping problems were related to a higher impact of the child's syndrome on the parent. Finally, emotional/behavioural problems were associated with higher parenting stress. Cognitive developmental level, autistic features and epilepsy were not a significant predictor of child HRQoL and parenting stress/impact.

CONCLUSIONS

These results suggest that interventions aimed at increasing child HRQoL and decreasing parenting stress/impact in AS should focus on child emotional/behavioural problems and sleeping problems, using a family-centred approach.

Neurodegeneration or dysfunction in Phelan-McDermid syndrome? A multimodal approach with CSF and computational MRI

BACKGROUND

Phelan-McDermid syndrome (PMS) is a rare multisystem disease with global developmental delay and autistic features. Genetically, the disease is based on a heterozygous deletion of chromosome 22q13.3 with involvement of at least part of the SHANK3 gene or heterozygous pathogenic variants in SHANK3. Pathophysiologically, this syndrome has been regarded as a synaptopathy, but current data suggest an additional concept, since axonal functions of neurons are also impaired, thus, the specific pathophysiological processes in this disease are not yet fully understood. Since symptoms of the autism spectrum, regression, and stagnation in development occur, we investigated whether neuroinflammatory and neurodegenerative processes may also play a role. To this end, we analysed biomarkers in cerebrospinal fluid (CSF) and parameters from magnetic resonance imaging with high-resolution structural T1w volumetry and diffusion tensor imaging analysis in 19 Phelan-McDermid syndrome patients.

RESULTS

CSF showed no inflammation but abnormalities in tau protein and amyloid-ß concentrations, however, with no typical biomarker pattern as in Alzheimer's disease. It could be demonstrated that these CSF changes were correlated with integrity losses of the fibres in the corticospinal tract as well as in the splenium and dorsal part of the cingulum. High CSF levels of tau protein were associated with loss of integrity of fibres in the corticospinal tract; lower levels of amyloid-ß were associated with decreasing integrity of fibre tracts of the splenium and posterior cingulate gyrus. Volumetric investigations showed global atrophy of the white matter, but not the grey matter, and particularly not in temporal or mesiotemporal regions, as is typical in later stages of Alzheimer's disease.

CONCLUSIONS

In summary, alterations of neurodegenerative CSF markers in PMS individuals could be demonstrated which were correlated with structural connectivity losses of the corticospinal tract, the splenium, and the dorsal part of the cingulum, which can also be associated with typical clinical symptoms in these patients. These findings might represent a state of dysfunctional processes with ongoing degenerative and regenerative processes or a kind of accelerated aging. This study should foster further clinical diagnostics like tau- and amyloid-PET imaging as well as novel scientific approaches especially in basic research for further mechanistic proof.

Heterogeneity of Autism Characteristics in Genetic Syndromes: Key Considerations for Assessment and Support

Purpose of Review

Elevated prevalence of autism characteristics is reported in genetic syndromes associated with intellectual disability. This review summarises recent evidence on the behavioural heterogeneity of autism in the following syndromes: Fragile X, Cornelia de Lange, Williams, Prader-Willi, Angelman, Down, Smith-Magenis, and tuberous sclerosis complex. Key considerations for assessment and support are discussed.

Recent Findings

The profile and developmental trajectory of autism-related behaviour in these syndromes indicate some degree of syndrome specificity which may interact with broader behavioural phenotypes (e.g. hypersociability), intellectual disability, and mental health (e.g. anxiety). Genetic subtype and co-occurring epilepsy within syndromes contribute to increased significance of autism characteristics. Autism-related strengths and challenges are likely to be overlooked or misunderstood using existing screening/diagnostic tools and criteria, which lack sensitivity and specificity within these populations.

Summary

Autism characteristics are highly heterogeneous across genetic syndromes and often distinguishable from non-syndromic autism. Autism diagnostic assessment practices in this population should be tailored to specific syndromes. Service provisions must begin to prioritise needs-led support.

Genesis, modelling and methodological remedies to autism heterogeneity

Diagnostic criteria used in autism research have undergone a shift towards the inclusion of a larger population, paralleled by increasing, but variable, estimates of autism prevalence across clinical settings and continents. A categorical diagnosis of autism spectrum disorder is now consistent with large variations in language, intelligence, comorbidity, and severity, leading to a heterogeneous sample of individuals, increasingly distant from the initial prototypical descriptions. We review the history of autism diagnosis and subtyping, and the evidence of heterogeneity in autism at the cognitive, neurological, and genetic levels. We describe two strategies to address the problem of heterogeneity: clustering, and truncated-compartmentalized enrollment strategy based on prototype recognition. The advances made using clustering methods have been modest. We present an alternative, new strategy for dissecting autism heterogeneity, emphasizing incorporation of prototypical samples in research cohorts, comparison of subgroups defined by specific ranges of values for the clinical specifiers, and retesting the generality of neurobiological results considered to be acquired from the entire autism spectrum on prototypical cohorts defined by narrow specifiers values.

Psychometric properties of the Mandarin version of the autism diagnostic observation Schedule-Generic

BACKGROUND/PURPOSE

The diagnosis of autism spectrum disorder (ASD), involving multiple components of clinical assessments, is challenging. The Autism Diagnostic Observation Schedule-Generic (ADOS-G), one of the standardized and validated instruments for ASD diagnostic evaluation, has been widely used in many countries. With the preparation of the Mandarin version of the ADOS-G (Mandarin-ADOS-G), this study aims to examine its psychometric properties, including reliability and validity.

METHODS

The sample included 554 individuals clinically diagnosed with ASD (477 males, 86.1%) and 50 typically developing (TD) individuals (29 males, 58.0%) who were assessed with different modules of the Mandarin-ADOS-G between 4.1 and 34.0 years old with a mean age of 13.0 years (Module 1, n = 40; Module 2, n = 46; Module 3, n = 275; Module 4, n = 243). We evaluated the inter-rater reliability, test-retest reliability, internal consistency, and concurrent validity with the Chinese Autism Diagnostic Interview-Revised (ADI-R) and Social Responsiveness Scale (SRS) caregiver-report and self-report forms. The discriminative validity of Mandarin-ADOS-G was also examined.

RESULTS

The Mandarin-ADOS-G demonstrated good inter-rater reliability (agreement of ADOS classification 0.91), good test-retest reliability (intraclass correlations 0.55-0.73), and low to high good internal consistency (Cronbach's alpha 0.27-0.86). The concurrent validity showed significant correlations with ADI-R (Pearson correlations 0.22-0.37) and the SRS caregiver-report form (Pearson correlations 0.15-0.23). Moreover, all Mandarin-ADOS-G domains successfully differentiated autistic individuals from TD individuals (all p-values <0.001).

CONCLUSION

The Mandarin-ADOS-G is a reliable and valid instrument for assisting the diagnosis of ASD in the Mandarin-speaking population.

Diagnostic validity of Autism Diagnostic Observation Schedule, second edition (K-ADOS-2) in the Korean population

Background

Although the Korean version of the Autism Diagnostic Observation Schedule-2 (K-ADOS‐2) is widely being used to diagnose autism spectrum disorder (ASD) in South Korea, no previous study has examined the validity and reliability of all modules of K-ADOS-2 across a wide age range, particularly older children, adolescents, and adults.

Method

Data from 2,158 participants were included (mean age = 79.7 months; 73.6% male): 1473 participants with ASD and 685 participants without ASD (Toddler Module, n = 289; Module 1, n = 642; Module 2 n = 574; Module 3 n = 411; Module 4, n = 242). Participants completed a battery of tests, including the K-ADOS or K-ADOS-2 and other existing diagnostic instruments. Sensitivity, specificity, area under the receiver operating characteristic (ROC) curve, positive predictive value (PPV), negative predictive value (NPV), Cohen’s kappa (k), and agreement with existing diagnostic instruments were computed. Cronbach’s α values were also calculated.

Results

All developmental cells of the K-ADOS-2 showed sufficient ranges of sensitivity 85.4–100.0%; specificity, 80.4–96.8%; area under the ROC curve, .90-.97; PPV, 77.8–99.3%; NPV, 80.6–100.0%; and k values, .83–.92. The kappa agreements of developmental cells with existing diagnostic instruments ranged from .20 to .90. Cronbach’s α values ranged from .82 to .91 across all developmental cells.

Limitation

The best-estimate clinical diagnoses made in this study were not independent of the K-ADOS-2 scores. Some modules did not include balanced numbers of participants in terms of gender and diagnostic status.

Conclusion

The K-ADOS-2 is a valid and reliable instrument in diagnosing ASD in South Korea. Future studies exploring the effectiveness of the K-ADOS-2 in capturing restricted, repetitive behaviors and differentiating ASD from other developmental disabilities are needed.

Supplementary Information

The online version contains supplementary material available at 10.1186/s13229-022-00506-5.

Abilities and Disabilities-Applying Machine Learning to Disentangle the Role of Intelligence in Diagnosing Autism Spectrum Disorders

Objective

Although autism spectrum disorder (ASD) is a relatively common, well-known but heterogeneous neuropsychiatric disorder, specific knowledge about characteristics of this heterogeneity is scarce. There is consensus that IQ contributes to this heterogeneity as well as complicates diagnostics and treatment planning. In this study, we assessed the accuracy of the Autism Diagnostic Observation Schedule (ADOS/2) in the whole and IQ-defined subsamples, and analyzed if the ADOS/2 accuracy may be increased by the application of machine learning (ML) algorithms that processed additional information including the IQ level.

Methods

The study included 1,084 individuals: 440 individuals with ASD (with a mean IQ level of 3.3 ± 1.5) and 644 individuals without ASD (with a mean IQ level of 3.2 ± 1.2). We applied and analyzed Random Forest (RF) and Decision Tree (DT) to the ADOS/2 data, compared their accuracy to ADOS/2 cutoff algorithms, and examined most relevant items to distinguish between ASD and Non-ASD. In sum, we included 49 individual features, independently of the applied ADOS module.

Results

In DT analyses, we observed that for the decision ASD/Non-ASD, solely one to four items are sufficient to differentiate between groups with high accuracy. In addition, in sub-cohorts of individuals with (a) below (IQ level ≥4)/ID and (b) above average intelligence (IQ level ≤ 2), the ADOS/2 cutoff showed reduced accuracy. This reduced accuracy results in (a) a three times higher risk of false-positive diagnoses or (b) a 1.7 higher risk for false-negative diagnoses; both errors could be significantly decreased by the application of the alternative ML algorithms.

Conclusions

Using ML algorithms showed that a small set of ADOS/2 items could help clinicians to more accurately detect ASD in clinical practice across all IQ levels and to increase diagnostic accuracy especially in individuals with below and above average IQ level.

Autism Spectrum Disorder and IQ - A Complex Interplay

Autism spectrum disorder (ASD) is characterized as a very heterogeneous child-onset disorder, whose heterogeneity is partly determined by differences in intelligence quotient (IQ). Older epidemiological studies suggested that the IQ-related spectrum tends to be skewed to the left, i.e., a larger proportion of individuals with ASD have below average intelligence, while only few individuals with ASD may have an IQ above average. This picture changed over time with broadening the spectrum view. Within the present perspective article, we discuss discrepancies in IQ profiles between epidemiological and clinical studies and identify potential underlying aspects, for example, the influence of external factors such as sample biases or differences in availability of autism health services. Additionally, we discuss the validity and reciprocal influences of ASD diagnostics and IQ measurement. We put the impact of these factors for diagnostic as well as care and support situations of patients into perspective and want to encourage further research to contribute to the conceptualization of "autism" more comprehensively including the IQ as well as to examine broader (life) circumstances, interacting factors and diagnostic requirements of given diagnoses in childhood as compared to adulthood.

Autism spectrum disorder in older adults with intellectual disability: a scoping review

INTRODUCTION

Ireland has an ageing population of persons with intellectual disability (ID), autism spectrum disorder (ASD) and both (ID/ASD). Despite this, little is known about the prevalence of ASD and its effect on functional outcomes, psychiatric comorbidity or diagnostic issues in an older population with ID. This article reviews the literature on older adults with ID/ASD and identifies opportunities for future research in this population.

METHOD

The authors searched the Medline, Pubmed, Embase, CINAHL and PsychInfo databases using the search terms using key words: (older adults) AND (ID OR mental retardation OR learning disability) AND (autism OR ASD). After excluding articles for relevance, a scoping review was carried out on the results retrieved.

RESULTS

Of the 1227 articles retrieved from the literature on ID and autism/ASD in older adults, 85 articles were relevant to an adult population with ID/ASD. The data were collated and are presented covering domains of diagnosis, prevalence, psychiatric comorbidities and functional outcomes.

CONCLUSIONS

Despite increased prevalence in childhood ASD in the last 20 years, there is a lack of research regarding adults, especially older adults, with ASD, up to half of whom will have some level of ID. The existing literature suggests that older adults with ID/ASD may have reduced functional independence, increased psychiatric comorbidity and psychotropic prescribing and more behavioural presentations than the older population generally or those with ID only. There is a need for longitudinal data to be collected on this ageing population so that care and management needs can be met in the future.

Assessment of Autism Spectrum Disorder in Deaf Adults with Intellectual Disability: Feasibility and Psychometric Properties of an Adapted Version of the Autism Diagnostic Observation Schedule (ADOS-2)

This study describes the adaptation of the autism diagnostic observation schedule (ADOS-2) to assess autism spectrum disorder (ASD) in adults with intellectual disability (ID) and hearing loss who communicate primarily visually. This adapted ADOS-2 was applied to residents of specialized therapeutic living communities (n = 56). The internal consistency of the adapted ADOS-2 was excellent for the Social Affect of modules 2 and 3 and acceptable for Restricted and Repetitive Behaviors subscale of module 2, but poor for module 3. Interrater reliability was comparable to standard ADOS-2 modules 1–3. Results suggest that autism symptoms of deaf adults with ID can be reliably identified by an adapted ADOS-2, provided adequate expertise in deafness, ID, ASD and proficiency in signed language by the administrator.

Autism Diagnostic Observation Schedule (ADOS-2) elevations in a clinical sample of children and adolescents who do not have autism: Phenotypic profiles of false positives

OBJECTIVE

While the Autism Diagnostic Observation Schedule, Second Edition (ADOS-2) shows high sensitivity for detecting autism spectrum disorder (ASD) when present (i.e. true positives), scores on the ADOS-2 may be falsely elevated for individuals with cognitive impairments or psychological concerns other than ASD (i.e. false positives). This study examined whether demographic, psychological, cognitive, and/or adaptive factors predict ADOS-2 false positives and which psychiatric diagnoses most often result in false positives.

METHOD

Sensitivity, specificity, false positive, and false negative rates were calculated among 214 5- to 16-year-old patients who completed an ADOS-2 (module 3) as part of an ASD diagnostic evaluation. Additional analyses were conducted with the 101 patients who received clinically elevated ADOS-2 scores (i.e. 56 true positives and 45 false positives).

RESULTS

Results revealed a 34% false positive rate and a 1% false negative rate. False positives were slightly more likely to be male, have lower restricted and repetitive behavior (RRB) severity scores on the ADOS-2, and demonstrate elevated anxiety during the ADOS-2. Neither IQ, adaptive functioning, nor caregiver-reported emotional functioning was predictive of false positive status. Trauma-related psychiatric diagnoses were more common among false positives.

CONCLUSIONS

The ADOS-2 should not be used in isolation to assess for ASD, and, in psychiatrically-complex cases, RRB symptom severity may be particularly helpful in differentiating ASD from other psychiatric conditions. Additionally, heightened levels of anxiety, more so than overactivity or disruptive behavior, may lead to non-ASD specific elevations in ADOS-2 scores.

Characterisation of the clinical phenotype in Phelan-McDermid syndrome

BACKGROUND

Phelan-McDermid syndrome (PMS) is a rare genetic disorder compromising the 22q13 terminal region and affecting SHANK3, a gene crucial to the neurobehavioural phenotype and strongly linked to autism (ASD) and intellectual disability (ID). The condition is characterised by global developmental delay, ID, speech impairments, hypotonia and autistic behaviours, although its presentation and symptom severity vary widely. In this study, we provide a thorough description of the behavioural profile in PMS and explore differences related to deletion size and language ability.

METHODS

We used standard clinical assessment instruments to measure altered behaviour, adaptive skills and autistic symptomatology in sixty participants with PMS (30 females, median age 8.5 years, SD=7.1). We recorded background information and other clinical manifestations and explored associations with deletion size. We performed descriptive and inferential analyses for group comparison.

RESULTS

We found delayed gross and fine motor development, delayed and impaired language (~70% of participants non or minimally verbal), ID of different degrees and adaptive functioning ranging from severe to borderline impairment. Approximately 40% of participants experienced developmental regression, and half of those regained skills. Autistic symptoms were frequent and variable in severity, with a median ADOS-2 CSS score of 6 for every domain. Sensory processing anomalies, hyperactivity, attentional problems and medical comorbidities were commonplace. The degree of language and motor development appeared to be associated with deletion size.

CONCLUSIONS

This study adds to previous research on the clinical descriptions of PMS and supports results suggesting wide variability of symptom severity and its association with deletion size. It makes the case for suitable psychotherapeutic and pharmacological approaches, for longitudinal studies to strengthen our understanding of possible clinical courses and for more precise genomic analysis.

Usefulness of current autism diagnostic or screening assessment tools in adults with intellectual disability (ID): systematic review of literature

Purpose

The purpose of the study is to identify and ascertain if there were any validated tools for diagnosing or screening autism spectrum disorder in adults with ID. The estimated prevalence of intellectual disability (ID) in the general population is about 10.37/1,000 population (Maulik et al., 2011). In total, 1 out of 4 individuals with ID suffers from an autism spectrum disorder (ASD) (Sappok et al., 2010). Early diagnosis and support for ASD is key to having a good quality of life. The diagnosis of ASD in people with an ID presents its own challenges and it is likely under-identification of ASD amongst adults with ID by about 20% to 30% (Emerson and Baines, 2010).

Design/methodology/approach

Studies were selected based on the following criteria: studies that reported either screening or diagnostic tools for ASD, participants had an ID i.e. a mean IQ of <70, adults i.e. participants were >18 years of age at the time of entry to the study and articles reported either sensitivity, specificity or area under the curve. Relevant studies that were published up to January 2020 were identified from EMBASE, PsychINFO, CINAHL and PubMed. In total, 75 papers were identified of which 15 papers met the criteria.

Findings

The screening or diagnostic tools currently in use is dependant on the degree of ID. A number of the tools had good psychometric properties and utility when used in people with specific degrees of ID or when used in combination with another screening or diagnostic tool. The authors could not identify a diagnostic tool that could be used across all levels of severity of ID unless used in combination. Hence, concluded that there is a need for a diagnostic tool with good psychometric properties for the assessment of ASD in adults with all degree of ID within a reasonable time period without the need for an additional tool to be used in conjunction.

Originality/value

Currently, the “gold standard” for diagnosing ASD is a lengthy and time-consuming process carried out by trained multi-disciplinary team members who assess historical, behavioural and parent/carer report to arrive at a diagnosis. There are a number of tools that have been developed to aid diagnosis. However, it is important to identify the tools that can optimise the procedures and are also time-efficient.

Differential diagnosis of autism spectrum disorder, intellectual disability and attention-deficit hyperactivity disorder (ADHD)

Purpose

Professionals working with community populations are often presented with complicated cases where it is difficult to determine which diagnosis or diagnoses are appropriate. Differentiating among neurodevelopmental disorders such as autism spectrum disorder (ASD), attention-deficit/hyperactivity disorder and intellectual disability can be a complex process, especially, as these disorders have some overlapping symptoms and often co-occur in young children. This series of case studies aims to present commonly overlapping symptoms in children who present to clinics with developmental concerns.

Design/methodology/approach

This paper presents three case studies that were completed at a free community ASD screening clinic in Southern California.

Findings

The case studies have common presenting behaviors and symptoms (e.g. social communication difficulties) that often co-occur across diagnoses; explanations for the final diagnoses are given in each case.

Research limitations/implications

Conclusions from these three cases cannot generalize to all children being seen in clinics for neurodevelopmental concerns.

Practical implications

This series of case studies highlights commonly overlapping symptoms in children who present for differential diagnosis with social and/or behavioral concerns. Implications for educational placement and intervention are discussed.

Social implications

These cases highlight the challenges involved in the differential and dual diagnostic process for young children with developmental concerns. Diagnostic considerations can affect later educational placement and opportunities for socialization.

Originality/value

This series of case studies provide practical information for clinicians about how to effectively differentiate between commonly occurring neurodevelopmental disorders, particularly given recent changes to the Diagnostic and Statistical Manual, 5th edition (DSM-5).

[Validity of the Scale of Pervasive Developmental Disorder in a Clinical Sample of Adults with Intellectual Disability]

OBJECTIVES

The study assesses the diagnostic validity of the Scale of Pervasive Developmental Disorder in Mentally Retarded Persons (PDD-MRS).

METHODS

Unblinded conduct of PDD-MRS in a clinical psychiatric sample of adults with intellectual disability (ID; N = 109) and suspect of autism.

RESULTS

For a cut-off-score of 10, sensitivity was 89 %, specificity 62 % and the Area Under the Curve (AUC) 0.83. The total score was independent of age, gender and level of ID. However the diagnostic validity was better balanced in adults with mild to moderate ID (sensitivity/specificity: 85 %/73 %) compared to those with severe to profound ID (93 %/42 %). The SEAS-M total score was correlated with various ASD screening measures (r = .3-.6), while no correlation was found for scales assessing challenging behavior.

CONCLUSION

To conclude, the PDD-MRS is a screening instrument for diagnosing autism in adults with mild to moderate ID. Knowledge of the PDD-MRS results within the consensus conference may have led to an overestimation of its diagnostic validity.

The Adapted ADOS: A New Module Set for the Assessment of Minimally Verbal Adolescents and Adults

Few measures are appropriate to assess autism symptoms in minimally verbal adolescents and adults. The Autism Diagnostic Observation Schedule, 2nd Edition (ADOS-2, Lord et al., in Autism diagnostic observation schedule-2nd edition (ADOS-2). Western Psychological Services, Los Angeles, 2012) Modules 1 and 2 were designed and validated with children whose spoken language ranges from few- to- no words to phrase speech. This study describes the development and initial validation of the Adapted-ADOS (A-ADOS), which includes tasks, materials and behavioral codes modified to be suitable for assessing older minimally verbal individuals. A-ADOS algorithms exhibit comparable sensitivity and improved specificity relative to ADOS-2 Modules 1 and 2. Although further validation is needed, the A-ADOS will facilitate research to further understanding of minimally verbal adults and symptom trajectories across the lifespan.

Development and Initial Utility of the Autism Clinical Interview for Adults: A New Adult Autism Diagnostic Measure

Background

Clinicians use diagnostic interviews to help them gather and organize information collected in the assessment of autism. Most instruments are developed for children and few measures have been developed that are reliable, valid, and appropriate for use in adulthood. This is a significant barrier to providing a high-quality, timely service for adults. The aim of this development study was to assess the initial utility of the recently developed Autism Clinical Interview for Adults (ACIA) for use in autism diagnostic clinical services before further large-scale testing and evaluation.

Methods

We invited adults who had received an autism spectrum diagnosis through a U.K. National Health Service (NHS) multidisciplinary adult autism assessment to participate. Seventeen autistic adults (8 women and 9 men, mean age of 37 years) and four relatives agreed to an interview. The semistructured ACIA interview comprises subject and informant versions, and a self-report preinterview questionnaire. In combination, the ACIA components cover topics relevant to autism and co-occurring condition assessment. We evaluated clinical utility and content validity via comparison with the Diagnostic and Statistical Manual Fifth Edition (DSM-5) and NHS diagnostic reports.

Results

Each interview took between 60 and 90 minutes to complete. Comparison with DSM-5 and the NHS autism diagnostic report demonstrated that the ACIA accurately identified information on core autism characteristics needed for a diagnosis, and identified co-occurring conditions. In response to participant suggestions we revised the interview.

Conclusions

These initial findings support the potential utility and validity of the ACIA for adult autism diagnostic clinical services. Further investigations of the acceptability, utility, and validity of this interview are planned.

Lay summary

Why was this study done?: Clinicians use diagnostic interviews during assessments to help gather and record information both from a person suspected to be on the autism spectrum and from an informant (someone who knows them well). However, most autism diagnostic interviews were originally developed for assessing autism in childhood, and few have been developed for use with adults. The lack of diagnostic interviews developed specifically for use with adults makes it difficult to provide a good-quality, consistent assessment.What was the purpose of this study?: The study tested a new semistructured diagnostic interview called the Autism Clinical Interview for Adults (ACIA). The ACIA includes a questionnaire for people to complete before their interview. This is followed by an interview that can be conducted with the person themselves and a separate version to be used with someone who knows them well (if permitted). The interview covers autism traits, strengths and difficulties, and co-occurring physical and mental health conditions. We wanted to find out if the interview is useful for autism diagnostic services by comparing information collected using the ACIA with clinical diagnostic reports.What did the researchers do?: We invited people who had received a diagnosis of autism from a U.K. National Health Service (NHS) assessment to take part in an interview. We asked them if we could also interview someone who knew them well, and if we could compare their NHS autism diagnostic report with information gathered using the ACIA.What were the results of the study?: Seventeen autistic adults (average age 37 years; 8 women and 9 men) and 4 relatives/supporters (2 parents, a spouse, and a cohabiting partner) agreed to be interviewed. Each interview took 60 to 90 minutes to complete. A comparison with clinical reports showed the ACIA identified autism traits relevant for a diagnosis, as well as co-occurring conditions (e.g., depression). Participants suggested some ways to improve the interview, and revisions were made.What do these findings add to what is already known?: There are few diagnostic interviews designed specifically for use with adults seeking a diagnosis of autism. The findings from this study show that the ACIA is a promising new interview.What are the potential weaknesses of the study?: The study is small. However, it is important to run an initial test study before involving more people and resources in larger studies. Building on these results, we aim to undertake further studies on the acceptability and usefulness of the new interview with a larger number of people, including people from a range of backgrounds.How will these findings help autistic people now or in the future?: The ACIA has potential for use in adult autism clinical assessment services and as a resource for research and training. The semistructured format helps gather important and relevant information, and the interview length supports feasibility in clinical and research settings. The ACIA has the potential to streamline autism assessments and speed up the process for adults who currently wait a long time for their diagnosis.

Rates and Predictors of Co-occurring Autism Spectrum Disorder in Boys with Fragile X Syndrome

Background and aims

Males with fragile X syndrome display many behavioral features of autism spectrum disorder. Despite this overlap, our understanding of autism spectrum disorder symptoms and severity in fragile X syndrome is limited due to variation in assessment methods in the literature. Furthermore, the relationship between autism spectrum disorder symptoms and child characteristics, like age, language, and cognitive abilities, are not well understood in individuals with fragile X syndrome. Therefore, the first research aim was to compare the rates of autism spectrum disorder classifications from three commonly reported autism spectrum disorder assessments in the literature. Our second research aim was to examine the relationship between autism spectrum disorder characteristics and other child characteristics.

Methods

The present study compared autism spectrum disorder classifications and symptoms using the Autism Diagnostic Observation Schedule, Autism Diagnostic Interview, Revised, and Childhood Autism Rating Scale, second edition in a sample of 33 school-age and adolescent boys with fragile X syndrome. In addition, the participants completed nonverbal IQ testing, expressive vocabulary and grammar tests, and a conversation language sample.

Results

The majority of the participants met criteria for autism spectrum disorder on the Autism Diagnostic Observation Schedule (96.97%) and Autism Diagnostic Interview, Revised (90.91%), while only half met criteria for autism spectrum disorder on the Childhood Autism Rating Scale, second edition. Sixteen boys (48.48%) met criteria for autism spectrum disorder on all three measures, and all participants met criteria for autism spectrum disorder on at least one measure. Expressive vocabulary accounted for a unique amount of variance in Childhood Autism Rating Scale, second edition and Autism Diagnostic Observation Schedule scores. Additionally, grammatical complexity accounted for a unique amount of variance in Childhood Autism Rating Scale, second edition scores. None of the child variables accounted for the variance found in Autism Diagnostic Interview, Revised scores. Although nonverbal IQ scores did not account for a significant amount of variance on the Autism Diagnostic Observation Schedule, Autism Diagnostic Interview, Revised, and Childhood Autism Rating Scale, Second Edition, boys who met criteria for autism spectrum disorder on all three measures had lower nonverbal IQ compared to the boys who did not. Additionally, mean length of utterance and expressive vocabulary scores were lower in the boys who met criteria for autism spectrum disorder on all three measures than those who did not.

Conclusions

Our findings identify areas of overlap and difference in the Autism Diagnostic Observation Schedule, Autism Diagnostic Interview, Revised, and Childhood Autism Rating Scale, second edition when used with males with fragile X syndrome. Variation in assessments may differentially identify the phenotypic behaviors of boys with fragile X syndrome that lead to a co-diagnosis of autism spectrum disorder, which contributes to the variation in reported co-morbidity of fragile X syndrome and autism spectrum disorder. Also, expressive language abilities, especially expressive vocabulary, are associated with autism spectrum disorder symptomatology.

Implications: When interpreting comorbid fragile X syndrome and autism spectrum disorder rates in the literature, it is important to consider the assessment tool that was used. Although the assessments that we used in the present study yielded scores that were highly correlated (i.e. Autism Diagnostic Observation Schedule and Childhood Autism Rating Scale, second edition), their categorical classifications did not align perfectly. Our findings also highlight the importance of considering language skills when assessing autism spectrum disorder severity in fragile X syndrome.

Severe white matter damage in SHANK3 deficiency: a human and translational study

Objective

Heterozygous SHANK3 mutations or partial deletions of the long arm of chromosome 22, also known as Phelan–McDermid syndrome, result in a syndromic form of the autism spectrum as well as in global developmental delay, intellectual disability, and several neuropsychiatric comorbidities. The exact pathophysiological mechanisms underlying the disease are still far from being deciphered but studies of SHANK3 models have contributed to the understanding of how the loss of the synaptic protein SHANK3 affects neuronal function.

Methods and results

Diffusion tensor imaging‐based and automatic volumetric brain mapping were performed in 12 SHANK3‐deficient participants (mean age 19 ± 15 years) versus 14 age‐ and gender‐matched controls (mean age 29 ± 5 years). Using whole brain–based spatial statistics, we observed a highly significant pattern of white matter alterations in participants with SHANK3 mutations with focus on the long association fiber tracts, particularly the uncinate tract and the inferior fronto‐occipital fasciculus. In contrast, only subtle gray matter volumetric abnormalities were detectable. In a back‐translational approach, we observed similar white matter alterations in heterozygous isoform–specific Shank3 knockout (KO) mice. Here, in the baseline data sets, the comparison of Shank3 heterozygous KO vs wildtype showed significant fractional anisotropy reduction of the long fiber tract systems in the KO model. The multiparametric Magnetic Resonance Imaging (MRI) analysis by DTI and volumetry demonstrated a pathology pattern with severe white matter alterations and only subtle gray matter changes in the animal model.

Interpretation

In summary, these translational data provide strong evidence that the SHANK3‐deficiency–associated pathomechanism presents predominantly with a white matter disease. Further studies should concentrate on the role of SHANK3 during early axonal pathfinding/wiring and in myelin formation.

Developing a Diagnostic Algorithm for the Music-Based Scale for Autism Diagnostics (MUSAD) Assessing Adults with Intellectual Disability

Initial studies have presented the Music-based Scale for Autism Diagnostics (MUSAD) as a promising DSM-5-based observational tool to identify autism spectrum disorder (ASD) in adults with intellectual disability (ID). The current study is the first to address its clinical utility in a new sample of 124 adults with ID (60.5% diagnosed with ASD). The derived diagnostic algorithm differentiated well between individuals with and without ASD (sensitivity 79%, specificity 74%, area under the curve = 0.81). Inter-rater reliability, assessed by the scorings of four independent experts in 22 consensus cases, was excellent (ICC = 0.92). Substantial correlations with scores from other ASD-specific measures indicated convergent validity. The MUSAD yields accurate and reliable scores, supporting comprehensive ASD diagnostics in adults with ID.

[ADI-R and ADOS and the differential diagnosis of autism spectrum disorders: Interests, limits and openings]

INTRODUCTION

Current developments in international public health are leading qualified authorities to release clinical practice guidelines for Autism Spectrum Disorders (ASD) assessment and diagnosis. Such documents incorporate procedures that rely on the Autism Diagnostic Interview-Revised (ADI-R) and the Autism Diagnostic Observation Schedule (ADOS) which are considered to be the "gold standard" assessment measures in the evaluation of ASD. Although these tools do prove their effectiveness in the evaluation of autistic symptomatology, they nevertheless stumble whenever the situation becomes more complex and reveal differential diagnostic issues in infantile and adult autism cases. This differential diagnostic issue remains significant in the clinical practice of daily life and has strong implications for the course of therapeutic treatment.

OBJECTIVES

Our objective is to underline and nuance the metrological qualities of the ADI-R and the ADOS in the differential diagnosis of autistic disorders by presenting a synthesis of recent studies, thus supporting the interest of maintaining an open debate on diagnostic practices.

METHODS

Our selective review of the recent literature focuses on studies that confront the ADI-R and the ADOS - used either independently or in a combination - with various differential issues in adulthood and childhood autism in order to highlight their qualities and limits.

RESULTS

The ADI-R is a semi-structured interview applied by trained examiners and applied to relatives and/or caregivers who collect developmental information about the patient's first years of life on a variety of behaviors and skills. It is therefore relatively dependent on the availability and personal bias of the interviewed third parties. Metric features highlighted by the reviewed studies straightforwardly reveal a certain effectiveness of the tool and a good discrimination of childhood disorders. At the same time, the tool's discriminatory capacity seems insufficient when applied to toddlers, very young children, and adults alike. The latter seems particularly true when it comes to differentiating between autistic and schizophrenic spectrum disorders. The ADOS is a semi-structured standardized observation assessment tool that has experienced several successive developments, such as optimizations concerning the sensitivity of its cutoffs. Many works have contributed to building such a tool with reliable and solid metric qualities which nevertheless retain important biases such as the subjectivity of the caregiver or the evaluator during the scoring process. For assessments of autistic children the tool still has a good diagnostic validity but seems to retain cases of incorrect diagnosis of ASD (false positives). In other words, disorders or developmental disabilities of some children and adolescents could not be distinguished from ASD when relying on this test alone. The ADOS Module 4, designed for the diagnosis of adolescents and adults with fluent speech, has undergone less updating. This revisited algorithm has metrological qualities useful for clinicians and remains one of the few available tools for this population. Unfortunately, its diagnostic accuracy is lower when applied to women, the elderly, people with personality disorders or higher intellectual abilities, or for the discrimination between ASD and schizophrenia. Overall, scores from these two instruments bring strong evidence of their usefulness in the diagnostic process of ASD, provided that they are used with caution and a critical clinical perspective, and only as a secondary technical support. Their use in combination is effective since they are complementary and compensate for each other's limitations. However, their globalized hegemony as "gold-standard" tools constitutes a setback insofar as it constrains the diagnosis of ASD to a set of stereotyped items. The latter in turn sets a normative model of autism that excludes other phenotypic forms, especially in the case of women and the elderly. Finally, the discrimination between autism and psychosis for children seems to remain an insoluble task even for the ADI-R/ADOS combination.

CONCLUSIONS

The problematics of differential diagnosis remain critical for clinical approaches to autism. Therefore, formalizations of the diagnostic procedures must be able to remain open-minded and accompanied by a creative clinical approach, especially in the case of complex situations that are not soluble by means of conventional diagnostic tools. One possibility may lie in the deepening of the phenomenological approach to autism as an attempt to model the subjective phenomena of autistic subjects and thus operationalize elements that serve the diagnostic process. In the same way, a psychodynamic epistemology could help clinicians to go beyond the consideration of observable behaviors and scores, introducing a psychoanalytic point of view that interfaces objective behaviors with the individual's dynamic intrapsychic functioning. This project could be articulated with projective methodologies - notably the Rorschach test - which respects the needs for standardization and quantification of conventionally used diagnostic tools.

Diagnosing Autism in Adults with Intellectual Disability: Validation of the DiBAS-R in an Independent Sample

The study assessed the diagnostic validity of the diagnostic behavioral assessment for autism spectrum disorders-revised (DiBAS-R; 19-item screening scale based on ratings by caregivers) in a clinical sample of 381 adults with ID. Analysis revealed a sensitivity of 0.82 and a specificity of 0.67 in the overall sample (70.3% agreement). Sensitivity (0.79) and specificity (0.84) were balanced in individuals with mild to moderate ID (83.3% agreement), while specificity was lower in individuals with severe to profound ID (sensitivity: 0.83, specificity: 0.34, 51% agreement). The level of ID as well as its interaction with ASD explained a significant proportion of the variance in the DiBAS-R scores. The DiBAS-R is an adequate screening tool, especially in individuals with mild to moderate ID.

Examining the Diagnostic Validity of Autism Measures Among Adults in an Outpatient Clinic Sample

Background

Previous research has questioned the validity of diagnostic measures for autism spectrum disorder (ASD) among adults. This study examined the correspondence between several measures and clinician diagnosis.

Methods

We conducted a retrospective chart review for 93 adults (18-61 years; 72% male) who received an ASD evaluation at a specialty outpatient clinic. Thirty-one individuals (33%) in the sample were diagnosed with ASD. We compared participant scores on the Autism Spectrum Quotient (AQ), the Ritvo Autism Asperger's Diagnostic Scale-Revised (RAADS-R), and the Autism Diagnostic Observation Schedule (ADOS) to clinician diagnosis of ASD. We calculated sensitivity, specificity, and area under the curve (AUC) for each measure.

Results

Participants diagnosed with ASD scored significantly higher, on average, on the ADOS than those who were not diagnosed with ASD, but not on the RAADS-R or AQ. The AUC was relatively low for each measure: ADOS = 0.69 (95% confidence interval [CI] 0.58-0.81), RAADS-R = 0.58 (95% CI 0.46-0.72), and AQ = 0.40 (95% CI 0.28-0.52). Sensitivity and specificity of all three measures were in the poor to fair range. When dichotomized at the optimal cutoffs for this sample, the ADOS had a sensitivity of 0.65 and a specificity of 0.76; the RAADS-R had a sensitivity of 0.52 and a specificity of 0.73; and the AQ had a sensitivity of 0.45 and a specificity of 0.52.

Conclusions

Results of the study suggest that clinicians should not rely solely on self-report measures or the ADOS when diagnosing adults on the spectrum. Further development of measures is needed, including self-report measures with higher diagnostic validity, that are sensitive across age, gender, and cognitive functioning, and that differentiate autism from psychiatric diagnoses.

Lay Summary

Why was this study done?: Diagnosing adults with autism spectrum disorder (ASD) is difficult. Other research has suggested that the few measures that exist for autistic adults may not be very effective for accurate diagnoses. We wanted to see how closely the results of commonly used ASD assessment tools compared with clinical diagnoses in a real-life outpatient setting.What did the researchers do?: This study looked at adults who went to an adult ASD outpatient clinic for an initial ASD diagnosis over 3 years. Of these 93 adults, one-third were diagnosed as autistic. As part of the evaluation, all participants completed two commonly used autism screening surveys-the Autism Spectrum Quotient (AQ) and the Ritvo Autism Asperger's Diagnostic Scale-Revised (RAADS-R)-and took part in a semistructured diagnostic interview called the Autism Diagnostic Observation Schedule (ADOS). The clinicians also collected additional information and, when possible, spoke to family members before jointly making a diagnosis. The researchers compared how those diagnosed with ASD and those who were not diagnosed with ASD scored on the AQ, the RAADS-R, and the ADOS.What were the results of this study?: Although adults on the spectrum scored higher on average on the ADOS clinical interview than those who did not receive an autism diagnosis, they did not score higher on the AQ and RAADS-R self-report measures. All three of the measures were only moderately effective at showing who would be diagnosed with ASD and who was not.What do these findings add to what was already known?: These results confirm and expand on findings from other prior studies. The findings suggest that ASD diagnostic measures should not be used alone or considered the only source of information when making an initial autism diagnosis in adulthood.What are potential weaknesses in the study?: When studying the accuracy of diagnostic tests, it is best to compare the results of the tests being studied with an "independent gold standard," that is, a test that we know is very good and that is totally separate from the tests being studied. In this case, there is no clear "gold standard," so we had to compare the tests with the next best thing-the clinicians' final decision about whether or not a client has a diagnosis of ASD. It is possible that the clinicians did not make the right diagnosis. Also, the diagnosis was not "independent" of the tests being studied, since the clinicians used the results of the tests to help make the diagnosis. Clinicians only diagnosed about one-third of adults in this study with ASD, whereas previous studies in community clinics have had a higher percentage of adults diagnosed; this factor may have influenced the measures' accuracy. Lastly, clinicians in this study did not assess clients for any other mental health conditions, which may have provided more information about the clients who were not diagnosed with ASD.How will these findings help autistic adults now or in the future?: The findings from this study suggest that none of these measures are very accurate on their own. Thus, we recommend multiple measures (interviews and questionnaires) should be used together when clinicians diagnose ASD in adulthood. Results of this study also suggest that measures for adults with ASD should be tested in real-world community clinics, so that clinicians and researchers see how the measures perform when used for initial diagnosis in adulthood.

The autism spectrum phenotype in ADNP syndrome

Pathogenic disruptions to the activity-dependent neuroprotector homeobox (ADNP) gene are among the most common heterozygous genetic mutations associated with autism spectrum disorders (ASDs). Individuals with ADNP disruptions share a constellation of medical and psychiatric features, including ASD, intellectual disability (ID), dysmorphic features, and hypotonia. However, the profile of ASD symptoms associated with ADNP may differ from that of individuals with another ASD-associated single gene disruption or with ASD without a known genetic cause. The current study examined the ASD phenotype in a sample of representative youth with ADNP disruptions. Participants (N = 116, ages 4-22 years) included a cohort with ADNP mutations (n = 11) and three comparison groups with either a mutation to CHD8 (n = 11), a mutation to another ASD-associated gene (other mutation; n = 53), or ASD with no known genetic etiology (idiopathic ASD; n = 41). As expected, individuals with ADNP disruptions had higher rates of ID but less severe social affect symptoms compared to the CHD8 and Idiopathic ASD groups. In addition, verbal intelligence explained more variance in social impairment in the ADNP group compared to CHD8, other mutation, and idiopathic ASD comparison groups. Restricted and repetitive behaviors in the ADNP group were characterized by high levels of stereotyped motor behaviors, whereas the idiopathic ASD group showed high levels of restricted interests. Taken together, these results underscore the role of ADNP in cognitive functioning and suggest that social impairments in ADNP syndrome are consistent with severity of verbal deficits. Autism Res 2018, 11: 1300-1310. © 2018 International Society for Autism Research, Wiley Periodicals, Inc. LAY SUMMARY: Disruptions to the ADNP gene (i.e., ADNP syndrome) have been associated with autism spectrum disorder (ASD). This article describes intellectual disability, mild social difficulties, and severe repetitive motor movements in a group of 11 youth with ADNP Syndrome. We found lower rates of ASD than previously reported. Verbal skills explained individual variability in social impairment. This pattern suggests that the ADNP gene is primarily associated with learning and memory, and level of social difficulties is consistent with level of verbal impairment.

Assessing Autism Spectrum Disorder in People with Sensory Impairments Combined with Intellectual Disabilities

People with sensory impairments combined with intellectual disabilities show behaviours that are similar to Autism Spectrum Disorder (ASD). The instrument Observation of Autism in people with Sensory and Intellectual Disabilities (OASID) was developed to diagnose ASD in this target group. The current study focuses on the psychometric properties of OASID. Sixty individuals with intellectual disabilities in combination with visual impairments and/or deafblindness participated in this study. The OASID assessment was administered and rated by three independent observers. By means of expert consensus cut-off scores for OASID were created. To determine the concurrent validity OASID was compared with the Pervasive Developmental Disorder for People with Mental Retardation (PDD-MRS) and the Childhood Autism Rating Scale second edition (CARS-2). The intra-rater reliability, the inter-rater reliability, internal consistency and concurrent validity of OASID were good to excellent. Cut-off scores were established based on criteria from the DSM-5. OASID was able to differentiate between four severity levels of ASD.

Framework for assessing individuals with rare genetic disorders associated with profound intellectual and multiple disabilities (PIMD): the example of Phelan McDermid Syndrome

BACKGROUND

Specialized strategies are needed to understand the complex neuropsychological impairments reported in individuals with profound intellectual and multiple disabilities (PIMD) associated with rare genetic disorders.

METHODS

This narrative review focuses on assessment of individuals with Phelan-McDermid Syndrome (PMS) as a condition commonly associated with PIMD. Published case series and prospective studies were reviewed to evaluate approaches to cognitive, language, motor/sensory, and behavioral domains. This review is framed using general principles for neuropsychological evaluation in PIMD.

RESULTS

Neuropsychological assessment domains and tools varied across published reports. Adaptive behavior measures, out-of-range developmental assessments, and social-communication measures were commonly used. Available findings were used to shape a recommended framework with potential to improve measurement of clinical outcomes and advance scientific discovery.

CONCLUSIONS

The recommended framework outlines an inter-disciplinary and multimodal neuropsychological assessment process relying on modified standardized assessments, functional assessments, and caregiver/informant reports when evaluating individuals with PIMD. Arrested development and skill variability/regression are also discussed as additional, important considerations in neuropsychological evaluation of individuals with PIMD and rare genetic disorders.

Diagnoses and characteristics of autism spectrum disorders in children with Prader-Willi syndrome

BACKGROUND

A small percentage of people with autism spectrum disorders (ASD) have alterations in chromosome 15q11.2-q3, the critical region for Prader-Willi syndrome (PWS). Data are limited, however, on the rates and characteristics of ASD in PWS. Previous estimates of ASD in PWS (25 to 41%) are questionable as they are based solely on autism screeners given to parents. Inaccurate diagnoses of ASD in PWS can mislead intervention and future research.

METHODS

One hundred forty-six children and youth with PWS aged 4 to 21 years (M = 11) were assessed with the Autism Diagnostic Observation Schedule-2 (ADOS-2). An expert clinical team-made best-estimate ASD diagnoses based on ADOS-2 videotapes, calibrated severity scores, and children's developmental histories and indices of current functioning. Children were also administered the Kaufman Brief Intelligence Test-2, and parents completed the Repetitive Behavior Scale-Revised and Vineland Adaptive Behavior Scales. Scores were compared across children with PWS + ASD versus PWS only. The performance of an ASD screener, the Social Communication Questionnaire (SCQ) and the ADOS-2 were evaluated in relation to best-estimate diagnoses.

RESULTS

Best-estimate diagnoses of ASD were made in 18 children, or 12.3% of the sample, and the majority of them had the maternal uniparental disomy (mUPD) PWS genetic subtype. Compared to the PWS-only group, children with PWS + ASD had lower verbal and composite IQ's and adaptive daily living and socialization skills, as well as elevated stereotypies and restricted interests. Regardless of ASD status, compulsivity and insistence on sameness in routines or events were seen in 76-100% of children and were robustly correlated with lower adaptive functioning. The SCQ yielded a 29-49% chance that screen-positive cases will indeed have ASD. The ADOS-2 had higher sensitivity, specificity and predictive values. Communication problems were seen in children who were ADOS-2 positive but deemed not to have ASD by the clinical team.

CONCLUSIONS

Autism screeners should not be the sole index of probable ASD in PWS; children need to be directly observed and evaluated. Compulsivity and insistence on sameness are salient in PWS and likely impede adaptive functioning. Most children with PWS only evidenced sub-threshold problems in social interactions that could signal risks for other psychopathologies.

Clinical Validity of the ADI-R in a US-Based Latino Population

The Autism Diagnostic Interview-Revised (ADI-R) has been validated as a tool to aid in the diagnosis of Autism; however, given the growing diversity in the United States, the ADI-R must be validated for different languages and cultures. This study evaluates the validity of the ADI-R in a US-based Latino, Spanish-speaking population of 50 children and adolescents with ASD and developmental disability. Sensitivity and specificity of the ADI-R as a diagnostic tool were moderate, but lower than previously reported values. Validity of the social reciprocity and restrictive and repetitive behaviors domains was high, but low in the communication domain. Findings suggest that language discordance between caregiver and child may influence reporting of communication symptoms and contribute to lower sensitivity and specificity.

Screening for ASD in adults with ID-moving toward a standard using the DiBAS-R and the ACL

BACKGROUND

Identification of Autism Spectrum Disorder (ASD) in persons with intellectual disability (ID) is challenging but essential to allow adequate treatment to be given. This study examines whether the combination of two ASD screening instruments specifically developed for persons with ID, namely, the Diagnostic Behavioral Assessment for ASD-Revised (DiBAS-R) and the Autism Checklist (ACL), improves diagnostic accuracy when used in combination compared to the application of the single instrument.

METHOD

A clinical sample of adults with ID who are suspected of having ASD (N =148) was assessed using two ID specific screening scales (DiBAS-R and ACL). The diagnostic validity of the single instruments and of their combination was assessed.

RESULTS

While both instruments showed acceptable diagnostic validity when applied alone (DiBAS-R/ACL: sensitivity: 75%/91%; specificity: 75%/75%; overall agreement: 75%/83%), specificity increased when two positive screening results were used (88%), and sensitivity increased (95%) when at least one positive screening result was used.

CONCLUSIONS

Different combinations of the ASD screening instruments DiBAS-R and ACL lead to improvements in sensitivity and specificity. The complementary use of the ACL in addition to the sole use of the DiBAS-R improves overall accuracy.

Development, behavior, and biomarker characterization of Smith-Lemli-Opitz syndrome: an update

BACKGROUND

Smith-Lemli-Opitz syndrome (SLOS) is an autosomal recessive inborn error of cholesterol metabolism syndrome with neurocognitive manifestations. SLOS is the result of mutations in the gene encoding the 7-dehydrocholesterol reductase, which results in the elevation of the cholesterol precursor 7-dehydrocholesterol (7-DHC). Previous reports indicate that intellectual disability, behavioral disturbances, and autism symptoms are frequently part of the SLOS behavioral phenotype. In the current study, we characterize the developmental history and current behavior of 33 individuals with SLOS aged 4 to 23 years and report on biomarkers 7-DHC and 8-DHC in relation to cognition and behavior.

METHODS

This was an observational case series, wherein participants with SLOS underwent extensive behavioral evaluation of cognitive function, adaptive function, autism symptoms, and problem behaviors, in addition to parent report of developmental milestones. Serum and CSF were contemporaneously obtained from the majority of participants.

RESULTS

Developmental milestones such as walking, talking, and toileting were uniformly delayed. Overall levels of cognitive and adaptive functioning were low; no participant received adaptive behavior scores in the average range, and the mean level of cognitive functioning in the full sample was in the moderate range of impairment. Aggressive behavior was present in nearly half of participants. Although the majority of participants had elevated scores on the gold standard autism diagnostic instruments, only about half of participants received a clinical diagnosis of autism spectrum disorder. Finally, while CSF cholesterol was not found to correlate with cognitive or adaptive functioning, both serum and CSF 7-DHC and 8-DHC (and their ratios with cholesterol) were moderately and negatively correlated with functioning in this group.

CONCLUSIONS

A history of developmental delay, followed by intellectual disability, is common in individuals with SLOS. Although autism spectrum disorder appears to be a frequent diagnosis in this population, it is apparent that the low level of functioning observed in SLOS may artificially inflate scores on standard autism assessments. Our findings further support that cholesterol precursors 7-DHC and 8-DHC are important biomarkers of the level of functioning in SLOS, especially regarding cognitive abilities, and thus may be to explore as mediators within the context of treatment trials.

TRIAL REGISTRATION

ClinicalTrials.gov, NCT00001721, NCT00064792.

Music-based Autism Diagnostics (MUSAD) - A newly developed diagnostic measure for adults with intellectual developmental disabilities suspected of autism

The MUSAD was developed as a diagnostic observational instrument in an interactional music framework. It is based on the ICD-10/DSM-5 criteria for autism spectrum disorder (ASD) and was designed to assess adults on a lower level of functioning, including individuals with severe language impairments. This study aimed to evaluate the psychometric properties of the newly developed instrument.

METHODS

Calculations were based on a consecutive clinical sample of N=76 adults with intellectual and developmental disabilities (IDD) suspected of ASD. Objectivity, test-retest reliability, and construct validity were calculated and a confirmatory factor analysis was applied to verify a reduced and optimized test version.

RESULTS

The structural model showed a good fit, while internal consistency of the subscales was excellent (ω>.92). Item difficulties ranged between .04≤pi≤.82 and item-total correlation from .21 to .85. Objectivity was assessed by comparing the scorings of two external raters based on a subsample of n=12; interrater agreement was .71 (ICC 2, 1). Reliability was calculated for four test repetitions: the average ICC (3, 1) was .69. Convergent ASD measures correlated significantly with the MUSAD, while the discriminant Modified Overt Aggression Scale (MOAS) showed no significant overlap.

CONCLUSION

Confirmation of factorial structure and acceptable psychometric properties suggest that the MUSAD is a promising new instrument for diagnosing ASD in adults with IDD.

Screening tools for autism spectrum disorders

Purpose

– Diagnosing autism spectrum disorder (ASD) is important over the whole life span. Standardized instruments may support the assessment process. The purpose of this paper is to describe English- and German-screening tools for ASD.

Design/methodology/approach

– PubMed was used to search for published tools and evidence on their diagnostic validity.

Findings

– Searches identified 46 screening tools for ASD. Most are designed for children, while only few measures are available for adults, especially those with additional intellectual disabilities. Many instruments are under-researched, although a small number such as the Modified Checklist for Autism in Toddlers and the SCQ have been widely examined in a variety of populations.

Originality/value

– The study identified and described a number of ASD screeners that can support clinicians or researchers when deciding whether to carry out a more comprehensive ASD assessment.

Validity of the social communication questionnaire in adults with intellectual disabilities and suspected autism spectrum disorder

This study examined the validity of the Social Communication Questionnaire (SCQ) to identify autism spectrum disorder (ASD) in 151 adults with intellectual disabilities (ID) in Germany. Sensitivities and specificities for ASD were 98/47% for the SCQ-current version and 92/22% for the SCQ-lifetime version. Sensitivities and specificities were increased to 89/66% and 78/48% by adjusting the recommended cut-points. The SCQ-current score correlated with the Scale for Pervasive Developmental Disorders in Mentally Retarded Persons and the Autism Diagnostic Observation Schedule, whereas the SCQ-lifetime score correlated with the Autism Diagnostic Interview-Revised. Our findings support the use of the SCQ-current version for ASD screening in adults with ID, although the SCQ-lifetime version should be used with caution in this population.