Dimensional Structure of the Autism Phenotype: Relations Between Early Development and Current Presentation

Differentiation of autism spectrum disorder and mood or anxiety disorder

Autism spectrum disorder shares many symptoms with other mental health disorders, and comorbid disorders such as mood and anxiety disorders are common, making the diagnostic process challenging. We aimed to explore the diagnostic accuracy of two standard autism spectrum disorder diagnostic instruments and to identify those behavioral items that best differentiate between autism spectrum disorder and mood and anxiety disorder in a naturalistic sample of patients utilizing autism spectrum disorder specialist services. The study included data of 847 participants (5–65 years of age, n = 586 with autism spectrum disorder, n = 261 with mood and anxiety disorder) all evaluated with the Autism Diagnostic Observation Schedule in the context of the diagnostic process. Data of the Autism Diagnostic Interview–Revised were available for 428 participants (5–51 years of age, n = 367 with autism spectrum disorder, n = 61 with mood and anxiety disorder). By means of binominal logistic regressions and an ensemble feature selection, we identified a subset of items that best differentiated between autism spectrum disorder and mood and anxiety disorder. Overall, the results indicate that a combination of communicational deficits and unusual and/or inappropriate social overtures differentiates autism spectrum disorder and mood and anxiety disorder. Aspects of social cognition are also relevant. Limitations of the current study and implications for research and practice are discussed.

Prevalence and Risk-Markers of Self-Harm in Autistic Children and Adults

Self-harm is purportedly common in autistic individuals, but under-researched, particularly in younger samples and those without intellectual disability. This study aimed to describe prevalence, profile and correlates of self-harm in autistic individuals without impairments in adaptive functioning. Parents of autistic participants (n = 83) completed questionnaires regarding the presence/topography of self-harm, demographic characteristics, autism severity, age of diagnosis, affect, activity levels and repetitive behaviour. 24.10% of participants engaged in self-harm. Self‐harm was associated with significantly higher levels of impulsivity, over-activity, negative affect, compulsive behaviour and insistence on sameness. Low mood and overactivity/impulsivity predicted the presence of self-harm, with the model correctly classifying 82.9% of cases. Findings highlight a role for impaired behavioural inhibition and low mood in the aetiological mechanisms underpinning self-harm in autism.

An initial examination of the psychometric properties of the Diagnostic Instrument for Social and Communication Disorders (DISCO-11) in a clinical sample of children with a diagnosis of Autism spectrum disorder

INTRODUCTION

The diagnostic interview for social and communication disorders (DISCO - 11; Wing 2006), is a semi-structured, interview-based instrument used in the diagnosis of children with autism spectrum disorder (ASD). This paper explores the psychometric properties of the DISCO-11 used in a specialist Paediatric clinical setting. Two key research questions were examined; (1) Does the factor structure of the DISCO-11 reflect the diagnostic and statistical manual 5th edition (DSM-5, American Psychiatric Association [APA], 2013) dyad of impairment in ASD? (2) Is there evidence of diagnostic stability over time using the DISCO?

METHODS

Review assessments of 65 children with ASD were carried out using standardised measures including the DISCO-11 and the autism diagnostic observation schedule.

RESULTS

The results revealed two factors resembling the DSM-5 algorithms, as used in DISCO-11, which were named as social-communication, and restricted and repetitive behaviours. The reliability, for the overall DISCO score was good (Cronbach's alpha = 0.78). The social communication and social interaction subscale showed good reliability (Cronbach's Alpha = 0.77) as did the restricted and repetitive patterns of behaviour, interests or activities subscale (Cronbach's Alpha = 0.74). Acceptable internal reliability was found for the overall DISCO score and the subscales of social communication and social interaction and the restricted and repetitive patterns of behaviour, interests or activities. Test-retest showed good stability of diagnosis over time.

DISCUSSION

This study supports that the DISCO-11 shows potential as a valid and reliable instrument that can be used both for clinical and research purposes.

Updated report on tools to measure outcomes of clinical trials in fragile X syndrome

OBJECTIVE

Fragile X syndrome (FXS) has been the neurodevelopmental disorder with the most active translation of preclinical breakthroughs into clinical trials. This process has led to a critical assessment of outcome measures, which resulted in a comprehensive review published in 2013. Nevertheless, the disappointing outcome of several recent phase III drug trials in FXS, and parallel efforts at evaluating behavioral endpoints for trials in autism spectrum disorder (ASD), has emphasized the need for re-assessing outcome measures and revising recommendations for FXS.

METHODS

After performing an extensive database search (PubMed, Food and Drug Administration (FDA)/National Institutes of Health (NIH)'s www.ClinicalTrials.gov, etc.) to determine progress since 2013, members of the Working Groups who published the 2013 Report evaluated the available outcome measures for FXS and related neurodevelopmental disorders using the COSMIN grading system of levels of evidence. The latter has also been applied to a British survey of endpoints for ASD. In addition, we also generated an informal classification of outcome measures for use in FXS intervention studies as instruments appropriate to detect shorter- or longer-term changes.

RESULTS

To date, a total of 22 double-blind controlled clinical trials in FXS have been identified through www.ClinicalTrials.gov and an extensive literature search. The vast majority of these FDA/NIH-registered clinical trials has been completed between 2008 and 2015 and has targeted the core excitatory/inhibitory imbalance present in FXS and other neurodevelopmental disorders. Limited data exist on reliability and validity for most tools used to measure cognitive, behavioral, and other problems in FXS in these trials and other studies. Overall, evidence for most tools supports a moderate tool quality grading. Data on sensitivity to treatment, currently under evaluation, could improve ratings for some cognitive and behavioral tools. Some progress has also been made at identifying promising biomarkers, mainly on blood-based and neurophysiological measures.

CONCLUSION

Despite the tangible progress in implementing clinical trials in FXS, the increasing data on measurement properties of endpoints, and the ongoing process of new tool development, the vast majority of outcome measures are at the moderate quality level with limited information on reliability, validity, and sensitivity to treatment. This situation is not unique to FXS, since reviews of endpoints for ASD have arrived at similar conclusions. These findings, in conjunction with the predominance of parent-based measures particularly in the behavioral domain, indicate that endpoint development in FXS needs to continue with an emphasis on more objective measures (observational, direct testing, biomarkers) that reflect meaningful improvements in quality of life. A major continuous challenge is the development of measurement tools concurrently with testing drug safety and efficacy in clinical trials.

Current Practice and Future Avenues in Autism Therapy

Autism spectrum disorders (ASDs) are neurodevelopmental disorders with early onset, characterized by deficits in social communication and repetitive and restricted interests and activities. A growing number of studies over the last 10 years support the efficacy of behaviorally based interventions in ASD for the improvement of social communication and behavioral functioning. In contrast, research on neurobiological based therapies for ASD is still at its beginnings. In this article, we will provide a selective overview of both well-established evidence-based treatments and novel interventions and drug treatments based on neurobiological principles aiming at improving core symptoms in ASD. Directions and options for future research on treatment in ASD are discussed.

Theory of mind predicts severity level in autism

We investigated whether theory of mind skills can indicate autism spectrum disorder severity. In all, 62 children with autism spectrum disorder completed a developmentally sensitive theory of mind battery. We used intelligence quotient, Diagnostic and Statistical Manual of Mental Disorders (4th ed.) diagnosis and level of support needed as indicators of severity level. Using hierarchical cluster analysis, we found three distinct clusters of theory of mind ability: early-developing theory of mind (Cluster 1), false-belief reasoning (Cluster 2) and sophisticated theory of mind understanding (Cluster 3). The clusters corresponded to severe, moderate and mild autism spectrum disorder. As an indicator of level of support needed, cluster grouping predicted the type of school children attended. All Cluster 1 children attended autism-specific schools; Cluster 2 was divided between autism-specific and special needs schools and nearly all Cluster 3 children attended general special needs and mainstream schools. Assessing theory of mind skills can reliably discriminate severity levels within autism spectrum disorder.

Systematic review of tools to measure outcomes for young children with autism spectrum disorder

BACKGROUND

The needs of children with autism spectrum disorder (ASD) are complex and this is reflected in the number and diversity of outcomes assessed and measurement tools used to collect evidence about children's progress. Relevant outcomes include improvement in core ASD impairments, such as communication, social awareness, sensory sensitivities and repetitiveness; skills such as social functioning and play; participation outcomes such as social inclusion; and parent and family impact.

OBJECTIVES

To examine the measurement properties of tools used to measure progress and outcomes in children with ASD up to the age of 6 years. To identify outcome areas regarded as important by people with ASD and parents.

METHODS

The MeASURe (Measurement in Autism Spectrum disorder Under Review) research collaboration included ASD experts and review methodologists. We undertook systematic review of tools used in ASD early intervention and observational studies from 1992 to 2013; systematic review, using the COSMIN checklist (Consensus-based Standards for the selection of health Measurement Instruments) of papers addressing the measurement properties of identified tools in children with ASD; and synthesis of evidence and gaps. The review design and process was informed throughout by consultation with stakeholders including parents, young people with ASD, clinicians and researchers.

RESULTS

The conceptual framework developed for the review was drawn from the International Classification of Functioning, Disability and Health, including the domains 'Impairments', 'Activity Level Indicators', 'Participation', and 'Family Measures'. In review 1, 10,154 papers were sifted - 3091 by full text - and data extracted from 184; in total, 131 tools were identified, excluding observational coding, study-specific measures and those not in English. In review 2, 2665 papers were sifted and data concerning measurement properties of 57 (43%) tools were extracted from 128 papers. Evidence for the measurement properties of the reviewed tools was combined with information about their accessibility and presentation. Twelve tools were identified as having the strongest supporting evidence, the majority measuring autism characteristics and problem behaviour. The patchy evidence and limited scope of outcomes measured mean these tools do not constitute a 'recommended battery' for use. In particular, there is little evidence that the identified tools would be good at detecting change in intervention studies. The obvious gaps in available outcome measurement include well-being and participation outcomes for children, and family quality-of-life outcomes, domains particularly valued by our informants (young people with ASD and parents).

CONCLUSIONS

This is the first systematic review of the quality and appropriateness of tools designed to monitor progress and outcomes of young children with ASD. Although it was not possible to recommend fully robust tools at this stage, the review consolidates what is known about the field and will act as a benchmark for future developments. With input from parents and other stakeholders, recommendations are made about priority targets for research.

FUTURE WORK

Priorities include development of a tool to measure child quality of life in ASD, and validation of a potential primary outcome tool for trials of early social communication intervention.

STUDY REGISTRATION

This study is registered as PROSPERO CRD42012002223.

FUNDING

The National Institute for Health Research Health Technology Assessment programme.

Review of factor analytic studies examining symptoms of autism spectrum disorders

Factor analytic studies have been conducted to examine the inter-relationships and degree of overlap among symptoms in Autism Spectrum Disorder (ASD). This paper reviewed 36 factor analytic studies that have examined ASD symptoms, using 13 different instruments. Studies were grouped into three categories: Studies with all DSM-IV symptoms, studies with a subset of DSM-IV symptoms, and studies with symptoms that were not specifically based on the DSM-IV. There was consistent support for a common social/communication domain that is distinct from a restricted and repetitive behaviours and interests domain. Implications for symptom conceptualization and diagnosis in ASD are discussed.

Measurement equivalence of the autism symptom phenotype in children and youth

BACKGROUND

The Autism Diagnostic Interview-Revised (ADI-R) is a gold standard assessment of Autism Spectrum Disorder (ASD) symptoms and behaviours. A key underlying assumption of studies using the ADI-R is that it measures the same phenotypic constructs across different populations (i.e., males/females, younger/older, verbal/nonverbal). The objectives of this study were to evaluate alternative measurement models for the autism symptom phenotype based on the ADI-R algorithm items and to examine the measurement equivalence of the most parsimonious and best fitting model across subgroups of interest.

METHODS

Data came from the Autism Genome Project consortium and consisted of 3,628 children aged 4-18 years (84.2% boys and 75% verbal). Twenty-eight algorithm items applicable to both verbal and nonverbal participants were used in the analysis. Measurement equivalence of the autism phenotype was examined using categorical confirmatory factor analysis.

RESULTS

A second-order model resembling the proposed DSM-5 two-factor structure of the phenotype showed good overall fit, but not for all the subgroups. The autism symptom phenotype was best indexed by the first-order, six-factor measurement model proposed by Liu et al. (2011). This model was well fitting and measurement equivalent across subgroups of participants (age, verbal ability and sex).

CONCLUSIONS

The autism symptom phenotype is adequately characterized by a six-factor measurement model; this model appears to be measurement equivalent across subgroups of children and youth with ASD that differ in age, sex and verbal ability. The two-factor model provides equally good fit for the sample as a whole, but comparison of these two dimensions between subgroups that might differ in terms of age, sex or verbal ability is challenged by lack of measurement equivalence.

Comparison of DSM-IV and DSM-5 factor structure models for toddlers with autism spectrum disorder

OBJECTIVE

The present study examined the factor structure of autism symptoms in toddlers, to aid understanding of the phenotype during the developmental period that represents the earliest manifestations of autism symptoms. This endeavor is particularly timely, given changes in symptom structure from the Diagnostic and Statistical Manual of Mental Disorders, Fourth Edition (DSM-IV) to the recently released Fifth Edition (DSM-5).

METHOD

Factor structure was examined in a sample of toddlers between 12 and 30 months of age (mean = 20.37 months, SD = 3.32 months) diagnosed with autism spectrum disorder (ASD) and recruited from community settings or referred for evaluation (N = 237). Confirmatory factor analyses were conducted comparing the relative fit of 4 distinct, previously proposed and validated models: DSM-5, DSM-IV, 1-factor, and an alternative 3-factor model proposed by van Lang et al.

RESULTS

Findings revealed that the 1-factor model provided the poorest fit, followed by the DSM-IV model and the van Lang et al. model. The DSM-5 model provided the best fit to the data relative to other models and good absolute fit. Indicators for the confirmatory factor analyses, drawn from the Autism Diagnostic Observation Schedule-Toddler Module (ADOS-T), loaded strongly onto the DSM-5 Social Communication and Social Interaction factor and more variably onto the DSM-5 Restricted/Repetitive Language and Behavior factor.

CONCLUSIONS

Results indicate that autism symptoms in toddlers, as measured by the ADOS-T, are separable and best deconstructed into the 2-factor DSM-5 structure, supporting the reorganization of symptoms in the DSM-5. Consistency of the present results in toddlers with previous studies in older children and adults suggests that the structure of autism symptoms may be similar throughout development.

Exploring the relationship between anxiety and insistence on sameness in autism spectrum disorders

Elevated anxiety symptoms are one of the most common forms of psychopathology to co-occur with autism spectrum disorders (ASDs). The purpose of this study was to explore the association between anxiety and ASD symptoms, particularly the degree to which the relationship is explained by insistence on sameness (IS) behaviors and/or cognitive ability. The sample included 1429 individuals aged 5:8-18:0 years who participated in the Simons Simplex Collection, a genetic consortium study of ASD. Child Behavior Checklist Anxiety Problems T-scores and Autism Diagnostic Interview-Revised "IS" item raw totals were treated as both categorical and continuous measures of anxiety and IS, respectively. Chronological age, verbal intelligence quotient (IQ), and a variety of ASD phenotype-related and other behavioral variables were assessed for potential association with anxiety and IS. Anxiety and IS continuous variables were minimally, although significantly, associated with each other and with chronological age and verbal IQ. Neither anxiety nor IS was associated with other core autism diagnostic scores. Anxiety was associated with a variety of other psychiatric and behavioral symptoms in ASD, including irritability, attention problems, and aggression, while IS was not. Anxiety and IS appear to function as distinct constructs, each with a wide range of expression in children with ASD across age and IQ levels. Thus, both variables could be of use in ASD behavioral research or in dimensional approaches to genetic exploration. Unlike IS, however, anxiety is related to non-ASD-specific behavioral symptoms.

Investigating phenotypic heterogeneity in children with autism spectrum disorder: a factor mixture modeling approach

BACKGROUND

Autism spectrum disorder (ASD) is characterized by notable phenotypic heterogeneity, which is often viewed as an obstacle to the study of its etiology, diagnosis, treatment, and prognosis. On the basis of empirical evidence, instead of three binary categories, the upcoming edition of the DSM 5 will use two dimensions - social communication deficits (SCD) and fixated interests and repetitive behaviors (FIRB) - for the ASD diagnostic criteria. Building on this proposed DSM 5 model, it would be useful to consider whether empirical data on the SCD and FIRB dimensions can be used within the novel methodological framework of Factor Mixture Modeling (FMM) to stratify children with ASD into more homogeneous subgroups.

METHODS

The study sample consisted of 391 newly diagnosed children (mean age 38.3 months; 330 males) with ASD. To derive subgroups, data from the Autism Diagnostic Interview-Revised indexing SCD and FIRB were used in FMM; FMM allows the examination of continuous dimensions and latent classes (i.e., categories) using both factor analysis (FA) and latent class analysis (LCA) as part of a single analytic framework.

RESULTS

Competing LCA, FA, and FMM models were fit to the data. On the basis of a set of goodness-of-fit criteria, a 'two-factor/three-class' factor mixture model provided the overall best fit to the data. This model describes ASD using three subgroups/classes (Class 1: 34%, Class 2: 10%, Class 3: 56% of the sample) based on differential severity gradients on the SCD and FIRB symptom dimensions. In addition to having different symptom severity levels, children from these subgroups were diagnosed at different ages and were functioning at different adaptive, language, and cognitive levels.

CONCLUSIONS

Study findings suggest that the two symptom dimensions of SCD and FIRB proposed for the DSM 5 can be used in FMM to stratify children with ASD empirically into three relatively homogeneous subgroups.

The structure of autism symptoms as measured by the autism diagnostic observation schedule

The current study tested several competing models of the autism phenotype using data from modules 1 and 3 of the ADOS. Participants included individuals with ASDs aged 3-18 years (N = 1,409) from the AGRE database. Confirmatory factor analyses were performed on total samples and subsamples based on age and level of functioning. Three primary models were tested, including a one-factor model, the DSM-IV model, and the anticipated DSM-V model. Results indicated all models fit similarly. Module 1 ratings yielded better indices of fit across all models and higher inter-factor correlations than Model 3. Model fits were impacted by age and level of functioning. The lack of differentiation between models suggests that the structure of ASD symptoms is complex to measure statistically.

[The concept of «multiple complex developmental disorder» - a disorder of social interaction, paranoid thinking and social anxiety in a 17-year-old boy]

OBJECTIVES

Multiple complex developmental disorder (MCDD) is a little-known disorder characterized by disturbances in the regulation of emotions, social interactions and thought disorders. Neither the classification system of ICD-10 nor the DSM-IV lists MCDD as an independent disorder.

METHODS

The study presents an overview on diagnostic criteria, current research and illustration by a case report of a 17-year-old adolescent.

RESULTS

MCDD, autistic disorders and schizophrenic disorders partially overlap. A clear classification or differentiation is currently not clearly possible.

CONCLUSIONS

Many open questions remain, and further research is needed.

Adults with autism spectrum disorders

In the decades since autism was first formally described in the 1940s, there have been major advances in research relating to diagnosis, causation, and treatment approaches for children with this condition. However, research into prognosis, outcomes, or effective interventions for adults with autism spectrum disorders (ASDs) is much more limited. In this paper, we review studies of outcome in adulthood. The findings indicate that, as adults, many people with ASD, including those of normal IQ, are significantly disadvantaged regarding employment, social relationships, physical and mental health, and quality of life. Support to facilitate integration within the wider society is frequently lacking, and there has been almost no research into ways of developing more effective intervention programs for adults. Moreover, most of the research on outcome has involved relatively young people in their 20s and 30s-much less is known about outcomes for people with ASD as they reach mid-late adulthood. Systematic follow-up studies from childhood through adulthood are needed if we are to gain a better understanding of trajectories of development over the lifespan, to identify the factors that influence prognosis, and to determine how these factors exert their effects and how they may be modified to ensure a better future.

The association between the social and communication elements of autism, and repetitive/restrictive behaviours and activities: a review of the literature

Research continues to try and pinpoint the etiological role of particular genes and brain structure in autistic spectrum disorder (ASD), but despite a host of biological, genetic and neuropsychological research, the symptom profile of pervasive developmental disorders (PDDs) are not yet linked to etiological theory. Debate continues around whether or not there is one single dimension that incorporates the three criteria domains of social difficulties, communication deficits and repetitive or restrictive interests and behaviours as a unitary 'ASD' concept, or whether PDD as they are currently described represent the co-occurrence of separate sub-domains of developmental difficulties. Although the three criteria need to be met for a diagnosis of PDD to be made, the association between them remains unclear. This review highlights that the majority of the literature that looks at the triad of impairments suggests the symptom structure does not match that proposed by diagnostic manuals, and that the triad may no longer fit as the best way to conceptualize ASD.

Confirmatory factor analysis of the Adult Asperger Assessment: the association of symptom domains within a clinical population

Autism Spectrum Disorder (ASD) is a behaviourally defined disorder characterised by impairments in three domains of social interaction, communication, and repetitive, stereotyped behaviours and activities. Proposed changes to diagnostic criteria suggest that the diagnostic triad may no longer fit as the best way to conceptualise ASD, and that social and communication impairments should be considered as a single domain. The aim of this study was to examine the structure of symptom domains within the Adult Asperger Assessment (AAA; Baron-Cohen, Wheelwright, Robinson, & Woodbury-Smith, 2005), a diagnostic tool for high functioning adults. As theoretical models already exist, confirmatory factor analysis was used to examine data from a clinical population of adults (n = 153) diagnosed with Asperger Syndrome (AS) and High Functioning Autism (HFA). Confirmatory factor analysis was used to fit different models based on the structure proposed by the authors of the AAA, the traditional triad and the newly proposed diagnostic dyad. Analysis suggested that none of the tested models were a good fit on the AAA dataset. However, it did highlight very high correlations between social and communication factors (r > 0.9) within unmodified models. The results of the analysis provide tentative support for the move towards considering ASD as a dyad of 'social-communication' impairments and repetitive/restricted interests behaviours and activities, rather than the traditional triad.

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.

Identification of genetic loci underlying the phenotypic constructs of autism spectrum disorders

OBJECTIVE

To investigate the underlying phenotypic constructs in autism spectrum disorders (ASD) and to identify genetic loci that are linked to these empirically derived factors.

METHOD

Exploratory factor analysis was applied to two datasets with 28 selected Autism Diagnostic Interview-Revised (ADI-R) algorithm items. The first dataset was from the Autism Genome Project (AGP) phase I (1,236 ASD subjects from 618 families); the second was from the AGP phase II (804 unrelated ASD subjects). Variables derived from the factor analysis were then used as quantitative traits in genome-wide variance components linkage analyses.

RESULTS

Six factors, namely, joint attention, social interaction and communication, nonverbal communication, repetitive sensory-motor behavior, peer interaction, and compulsion/restricted interests, were retained for both datasets. There was good agreement between the factor loading patterns from the two datasets. All factors showed familial aggregation. Suggestive evidence for linkage was obtained for the joint attention factor on 11q23. Genome-wide significant evidence for linkage was obtained for the repetitive sensory-motor behavior factor on 19q13.3.

CONCLUSIONS

This study demonstrates that the underlying phenotypic constructs based on the ADI-R algorithm items are replicable in independent datasets, and that the empirically derived factors are suitable and informative in genetic studies of ASD.

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.

Categorical and dimensional structure of autism spectrum disorders: the nosologic validity of Asperger Syndrome

There is an ongoing debate whether a differentiation of autistic subtypes, especially between Asperger Syndrome (AS) and high-functioning-autism (HFA) is possible and if so, whether it is a categorical or dimensional one. The aim of this study was to examine the possible clustering of responses in different symptom domains without making any assumption concerning diagnostic appreciation. About 140 children and adolescents, incorporating 52 with a diagnosis of AS, 44 with HFA, 8 with atypical autism and 36 with other diagnoses, were examined. Our study does not support the thesis that autistic disorders are discrete phenotypes. On the contrary, it provides evidence that e.g. AS and autism are not qualitatively distinct disorders, but rather different quantitative manifestations of the same disorder.

Health-related quality of life in adolescents and young adults with high functioning autism-spectrum disorder

AIM

Over the last years, health-related quality of life (HRQOL) has emerged as an important measure not only in somatic medicine but also in psychiatry. To date, there are only few reports on HRQOL in patients with autism-spectrum disorder (ASD). This study aimed at studying HRQOL in ASD patients with an IQ >70, using a self-report HRQOL questionnaire with cross-cultural validity.

METHODS

In this cross-sectional study, twenty-six male adolescents and young adults with the diagnosis of Asperger Syndrome, high functioning autism and atypical autism were evaluated, using the German version of the WHOQOL-BREF HRQOL questionnaire.

RESULTS

Mean WHOQOL-BREF global scores were 60.6 (SD ±26.1), mean WHOQOL-BREF subscale scores were 70.1 (SD ±19.1) for the domain "physical health", 61.5 (SD ±21.9) for the domain "psychological health", 53.8 (SD ±23.5) for the domain "social relationships" and 67.9 (SD ±17.4) for the domain "environment". Compared to a reference population of healthy controls, our sample scored significantly lower in three of four WHOQOL-BREF domains. In comparison to a reference sample of individuals with schizophrenia spectrum disorder (SSD), HRQOL of our sample was significantly better in all domains except for the "social relations" domain. There was a significant association between HRQOL and the Vineland Adaptive Behavior Scales domain "daily living skills", but not with age, IQ, or ADOS-G summary scores.

CONCLUSION

Overall self-reported HRQOL in patients with high functioning ASD seems to be lower than in healthy individuals, but better than in patients with SSD. Also, higher HRQOL was associated with better daily living skills. This interrelationship should especially be accounted for in the design and application of treatment programmes for individuals with ASD, as it is of importance for the level of self-perceived HRQOL.

Evidence for the involvement of genetic variation in the oxytocin receptor gene (OXTR) in the etiology of autistic disorders on high-functioning level

An increasing number of animal studies advert to a substantial role of the neuropeptide oxytocin in the regulation of social attachment and affiliation. Furthermore, animal studies showed anxiety and stress-reduced effects of oxytocin. First human studies confirm these findings in animal studies and implicate a crucial role of oxytocin in human social attachment behavior and in social interactions. Thus, the oxytocin system might be involved in the impairment of social interaction and attachment in autism spectrum disorders (ASD). The human oxytocin receptor gene (OXTR) represents a plausible candidate gene for the etiology of ASD. To analyze whether genetic variants in the OXTR gene are associated with ASD we performed family-based single-marker and haplotype association analyses with 22 single nucleotide polymorphisms (SNPs) in the OXTR and its 5' region in 100 families with autistic disorders on high-functioning level (Asperger syndrome (AS), high-functioning autism (HFA), and atypical autism (AA)). Single-marker and haplotype association analyses revealed nominally significant associations of one single SNP and one haplotype with autism, respectively. Furthermore, employing a "reverse phenotyping" approach, patients carrying the haplotype associated with autism showed nominally significant impairments in comparison to noncarriers of the haplotype in items of the Autism Diagnostic Interview-Revised algorithm describing aspects of social interaction and communication. In conclusion, our results implicate that genetic variation in the OXTR gene might be relevant in the etiology of autism on high-functioning level.

Update on autism: a review of 1300 reports published in 2008

This publication, by reviewing 1300 studies published on autism in 2008, represents an update on this topic. Results include possible parental influences, maternal conditions, and studies on genes and chromosomes. Possible etiological factors involve the "extreme male brain," defects in the mirror neuron system, vaccines, underconnectivity, disorders of central coherence, and many other more specific etiologies. Assessments or tests for autism are also reviewed. Characteristics of autistic individuals include repetitive behavior, language disorders, sleep disturbances, social problems, joint attention disorders, seizures, allergic reactions, and various behavioral changes. Cognitive changes involve IQ, reasoning, and verbal and language disorders. The savant syndrome is a fascinating phenomenon, at times seen in autistic individuals. Neurophysiological and neuroanatomical changes are also reviewed, as are comorbid conditions. Finally, treatment involves various medications including risperidone, ziprasidone, and antipsychotic drugs, as well as different procedures such as magnetic stimulation, acupuncture, and hyperbaric oxygen therapy. As mentioned in the 2007 survey, nearly every conceivable problem that a child can have may be found in these unfortunate children and nearly every conceivable etiology has been mentioned to account for this serious disorder.