Predictive validity of self-report questionnaires in the assessment of autism spectrum disorders in adults.

While various screening instruments for autism spectrum disorders are widely used in diagnostic assessments, their psychometric properties have not been simultaneously evaluated in the outpatient setting where these instruments are used most. In this study, we tested the Ritvo Autism Asperger Diagnostic Scale-Revised and two short versions of the Autism-Spectrum Quotient, the AQ-28 and AQ-10, in 210 patients referred for autism spectrum disorder assessment and in 63 controls. Of the 210 patients, 139 received an autism spectrum disorder diagnosis and 71 received another psychiatric diagnosis. The positive predictive values indicate that these tests correctly identified autism spectrum disorder patients in almost 80% of the referred cases. However, the negative predictive values suggest that only half of the referred patients without autism spectrum disorder were correctly identified. The sensitivity and specificity of each of these instruments were much lower than the values reported in the literature. In this study, the sensitivity of the Ritvo Autism Asperger Diagnostic Scale-Revised was the highest (73%), and the Autism-Spectrum Quotient short forms had the highest specificity (70% and 72%). Based on the similar area under the curve values, there is no clear preference for any of the three instruments. None of these instruments have sufficient validity to reliably predict a diagnosis of autism spectrum disorder in outpatient settings.

Cognitive shifting and externalising problem behaviour in intellectual disability and autism spectrum disorder.

BACKGROUND: Behavioural problems are frequently reported in residential care for people with an intellectual disability (ID) in particular when they are additionally diagnosed with autism spectrum disorder (ASD). There are indications that impairment in cognitive shifting may be associated with problem behaviour. The objectives of this study were (1) to examine the relationship of cognitive shifting and severity of ASD symptoms with externalising problem behaviour in individuals with ID, with and without ASD, and (2) to examine whether a diagnosis based on shifting impairment is more predictive of externalising problem behaviour than an ASD diagnosis. METHOD: Participants consisted of adolescents and young adults with mild ID, with and without ASD (n = 41). Pearson intercorrelations were computed to explore the relationship between shifting impairment and severity of ASD symptoms on the one hand and ratings of externalising problem behaviour on the other hand. t-Tests were performed to analyse differences in externalising problem behaviour. RESULTS: Unlike ASD symptom severity, shifting scores were found to be associated with externalising problem behaviour, but only if shifting was measured using rating scales and not when using neuropsychological tasks. Externalising problem behaviour scores significantly differed when groups were classified according to shifting impairment (impaired vs. non-impaired) but not when they were classified according to ID and ASD diagnoses. CONCLUSIONS: It is proposed to use a cognition-based approach when analysing problem behaviour, thus concentrating not so much on ID and ASD diagnosis and their corresponding symptoms, but rather placing the focus on cognitive symptoms.

Do social networks differ? Comparison of the social networks of people with intellectual disabilities, people with autism spectrum disorders and other people living in the community.

The aim of this study was to determine the similarities and differences in social network characteristics, satisfaction and wishes with respect to the social network between people with mild or borderline intellectual disabilities (ID), people with autism spectrum disorders (ASD) and a reference group. Data were gathered from 105 young adults living independently in the community. The social networks of people with ID and ASD are more restricted than those of the reference group. Compared with the other groups, people with ASD are less often satisfied with their networks. Each group has its own characteristics, issues and wishes with respect to their social network. Practical measures to enable professionals to adapt to these issues are discussed.

Executive functioning in individuals with intellectual disabilities and autism spectrum disorders.

BACKGROUND: Executive functioning (EF) is important for adequate behavioural functioning and crucial for explaining symptoms of autism spectrum disorders (ASD) in individuals with normal intelligence, but is scarcely studied in individuals with ASD and intellectual disabilities (ID). We therefore study EF in an ID population by comparing performances on three frequently studied executive functions (shifting, inhibition and updating) between individuals with ASD and individuals without ASD. When studying ID populations, one should be aware of Spearman's Law of Diminishing Returns (SLODR), as it questions the possibility of measuring separate cognitive functions in ID populations. METHODS: Six EF tasks were administered to 50 individuals with mild to borderline ID, of which half was diagnosed with ASD. In order to investigate the distinctness of the three executive functions in this ID sample, the results on the six EF tasks were subjected to principal components analysis (PCA). Subsequently, a multivariate analysis of variance (MANOVA) was performed to assess differences between the ASD and non-ASD group on shifting, inhibition and updating. RESULTS: The PCA revealed the hypothesised EF trichotomy. MANOVA analysis showed no significant group differences on EF-performance. CONCLUSIONS: Three separate executive functions were measured in this ID population, but despite much evidence that individuals with ASD display more behavioural problems and the proven relevance of EF in behavioural functioning, no significant group difference was found on shifting, inhibition or updating. After this first effort to achieve more insight into EF of individuals with ASD and ID the relation between behavioural problems and EF will require further study.

Shifting impairment and aggression in intellectual disability and autism spectrum disorder.

Aggressive behaviour is a major problem in individuals with an intellectual disability (ID) as well as in individuals with an Autism Spectrum Disorder (ASD). There are indications that suggest a link between cognitive shifting and aggression. In this study, reports of aggressive incidents of adolescents and young adults with different clinical diagnoses (ID, ID+ASD, ASD) were collected during 1 year, using the Staff Observation Aggression Scale-Revised. Whether they were diagnosed with ID, ASD or both; individuals who displayed aggression were found to face more cognitive shifting difficulties than non-aggressive individuals, while no significant differences were found on severity of ASD symptoms. Study results support the assumption that a cognition-based model for aggression may be more adequate than a diagnose-based model.

Brief report: relationship between self-awareness of real-world behavior and treatment outcome in autism spectrum disorders.

The aim of the present study was to investigate the influence of self-awareness of real-world behavior on treatment outcome in adolescents with ASD. For this purpose we followed 28 adolescents with ASD during their first year of specialized treatment. Results showed that better self-awareness at start of treatment was related with an increase in clinician-reported social functioning after 1 year of treatment. Additionally, an increase in self-awareness during treatment was related with a decrease of parent-reported problems in daily functioning. However, an increase in self-awareness was also related to an increase of self-reported daily and psychological problems. It is discussed that lowered self-awareness may result in an overestimation of personal real-world functioning and consequently may influence treatment course.

[Cognitive predictors of social improvement in adolescents with autism spectrum-disorders]. / Cognitieve voorspellers van sociale vooruitgang bij jongeren met een autismespectrumstoornis.

BACKGROUND: In an earlier study published in this journal (Berger e.a. 2002) it was shown that the cognitive styles 'weak central coherence' and 'poor cognitive shifting' are common in autism spectrum disorders, but tests have revealed that the styles do not apply to every member of the patient group. This finding could have consequences for the course of treatment. AIM: To find out if the cognitive styles of autistic patients can predict whether their social functioning will improve after three years of treatment we conducted a follow-up study in which we examined 44 non-retarded adolescents with an autism spectrum disorder who were receiving residential treatment. METHOD: On the basis of factor scores awarded in an extensive battery of neuropsychological tests, we formed subgroups of patients with weak versus strong central coherence and cognitive shifting. Then analyses of variance were used to discover whether the subgroups were predictors of changes in three aspects of social functioning: autistic symptoms, social intelligence and social competence. RESULTS: We found a small but significant gain in all the social domains. However, there were clear individual differences in the degree of improvement. Cognitive shifting was found to be a predictor of a clinically meaningful improvement in social competence. CONCLUSION: The correlation found between cognitive shifting and social competence indicates that patients with an autism spectrum disorder should be given different forms of treatment that take differences in cognitive style into account.

Cognitive styles in high-functioning adolescents with autistic disorder.

This study addressed the operationalization, the identification, and the prevalence of weak central coherence and poor cognitive shifting in 35 high-functioning adolescents with autism. Central coherence and cognitive shifting were represented by two factors in a factor analysis, each reflecting a constituent aspect of the domain in question. With regard to central coherence, these aspects were the ability of piecemeal processing and the ability to process meaning. The aspects related to cognitive shifting concerned internally and externally controlled shifting. Weak central coherence and poor cognitive shifting did not appear to be related to measures of symptom severity, social understanding, and social competence. Both these cognitive styles did not appear to be universal to autism. In our sample, weak central coherence and poor cognitive shifting were found to be significantly more common than in normative control subjects.

Impaired categorical perception of facial expressions in high-functioning adolescents with autism.

Categorical perception of facial expressions is studied in high-functioning adolescents with autism, using three continua of facial expressions obtained by morphing. In contrast to the results of normal adults, the performance on the identification task in autistic subjects did not predict performance on the discrimination task, an indication that autistic individuals do not perceive facial expressions categorically. Performance of autistic subjects with low social intelligence was more impaired than that of subjects with higher social IQ scores on the expression recognition of unmanipulated photographs. It is suggested that autistic subjects with higher social intelligence may use compensatory strategies that they have acquired in social training programs This may camouflage the deficits of this subgroup in the perception of facial expressions.

Relationship between memory strategies and motor symptoms in Parkinson's disease.

Patients with Parkinson's disease(PD) show a serious decrease in performance on tasks which lack explicit guidelines and which necessitate the subject to develop his or her own strategy. Using the California Verbal Learning Task(CVLT) we have found evidence that this phenomenon becomes also manifest in learning and memory. The goal of the present study on PD was to investigate whether or not there is an intrinsic relationship between PD-specific deviant learning characteristics and the severity of motor symptomatology. The results show, as expected, a significant correlation between the severity of bradykinetic/hypokinetic symptoms and the serial clustering gradient of the CVLT: the more bradykinetic PD patients (n = 48) were, the more they were dependent on the externally guided serial learning strategy. The findings are discussed in the context of our hypothesis that the actual deficit in patients with PD is a deficient processing of ambiguous internal cues.

Do autistics have a generalized face processing deficit?

The study presents results from a clinical test battery (Bruyer & Schweich, 1991; Schweich & Bruyer, 1993) that is used to study components in the face recognition system of autistic children. The results of the autistics are compared with the performance of two age groups of normal children (7-10 years, 12-16 years) and an adult control group. Autistic subjects, like young children, make more errors on a task in which they have to match facial features in the context of a complete face but not when the features are presented in isolation or in a simplified facial context. Finally, the sensitivity of the battery for clinical populations other than prosopagnosics is discussed.