Outcome in high-functioning adults with autism with and without early language delays: implications for the differentiation between autism and Asperger syndrome

Advanced mind-reading in adults with Asperger syndrome

This study investigated the mind-reading abilities of 19 adults with Asperger syndrome and 19 typically developing adults. Two static mind-reading tests and a more naturalistic empathic accuracy task were used. In the empathic accuracy task, participants attempted to infer the thoughts and feelings of target persons, while viewing a videotape of the target persons in a naturally occurring conversation with another person. The results are consistent with earlier findings. The empathic accuracy task indicated significant between-group differences, whereas no such differences were found on the static mind-reading tasks. The most innovative finding of the present study is that the inference ability of adults with pervasive developmental disorder (PDD) and controls depends on the focus of the target's thoughts and feelings, and that the empathic accuracy of adults with Asperger syndrome and control adults might be different in terms of quantity and quality.

The amygdala is enlarged in children but not adolescents with autism; the hippocampus is enlarged at all ages

Autism is a neurodevelopmental disorder characterized by impairments in reciprocal social interaction, deficits in verbal and nonverbal communication, and a restricted repertoire of activities or interests. We performed a magnetic resonance imaging study to better define the neuropathology of autistic spectrum disorders. Here we report findings on the amygdala and the hippocampal formation. Borders of the amygdala, hippocampus, and cerebrum were defined, and their volumes were measured in male children (7.5-18.5 years of age) in four diagnostic groups: autism with mental retardation, autism without mental retardation, Asperger syndrome, and age-matched typically developing controls. Although there were no differences between groups in terms of total cerebral volume, children with autism (7.5-12.5 years of age) had larger right and left amygdala volumes than control children. There were no differences in amygdala volume between the adolescent groups (12.75-18.5 years of age). Interestingly, the amygdala in typically developing children increases substantially in volume from 7.5 to 18.5 years of age. Thus, the amygdala in children with autism is initially larger, but does not undergo the age-related increase observed in typically developing children. Children with autism, with and without mental retardation, also had a larger right hippocampal volume than typically developing controls, even after controlling for total cerebral volume. Children with autism but without mental retardation also had a larger left hippocampal volume relative to controls. These cross-sectional findings indicate an abnormal program of early amygdala development in autism and an abnormal pattern of hippocampal development that persists through adolescence. The cause of amygdala and hippocampal abnormalities in autism is currently unknown.

Emanuel Miller lecture: confusions and controversies about Asperger syndrome

BACKGROUND

Hans Asperger drew attention to individuals who show the core symptoms of autism in the presence of high verbal intelligence.

METHODS

A review of the literature explores current issues concerning the diagnosis and nature of Asperger syndrome.

RESULTS

The behavioural and neurophysiological evidence to date suggests that Asperger syndrome is a variant of autism typically occurring in high-functioning individuals, and not a separate disorder. One of the problems of diagnosis is that the typical impairment of social communication may be difficult to identify in early childhood, and can be camouflaged in adulthood by compensatory learning. The range and nature of the social impairments in Asperger syndrome are still in need of investigation, but appear to be less severe than in autism. Experimental evidence suggests that individuals with Asperger syndrome may lack an intuitive theory of mind (mentalising), but may be able to acquire an explicit theory of mind. Brain imaging studies pinpoint a network that links medial prefrontal and temporal cortex as the neural substrate of intuitive mentalising. This network shows reduced activation and poor connectivity in Asperger syndrome. While some individuals with Asperger syndrome have written eloquently about their lives, their ability to talk about their own emotions appears to be impaired (alexithymia). This impairment may be linked to depression and anxiety, which is common in adulthood. Little is as yet known about the often considerable cognitive strengths in Asperger syndrome, or about the difficulties observed in higher-level executive skills.

CONCLUSIONS

Studies are needed that define the developmental course of the disorder and the nature of the strengths and weaknesses in both social and non-social domains. This requires more sensitive assessment instruments than are currently available. Questions about the prevalence of Asperger syndrome, about associated and secondary features, and about optimal education and management, urgently call for such studies.

Annotation: The similarities and differences between autistic disorder and Asperger's disorder: a review of the empirical evidence

BACKGROUND

The ongoing controversy over the distinction between autistic disorder and Asperger's disorder is important to resolve because of the implications regarding an understanding of the aetiology and prognosis, and the diagnostic and clinical practices relating to these conditions. This paper provides a critical evaluation of current published research evidence.

METHOD

Databases, such as PsychINFO and Medline, as well as book chapters, reference lists from relevant articles, and recent editions of key journals were searched for all relevant studies (until 2002) which incorporated participants diagnosed with high-functioning autism and Asperger's disorder using either cluster analysis or comparative approaches to examine similarities and differences between these groups. Keywords used in the searches included autistic disorder, Asperger's disorder, autism, high-functioning autism, and pervasive developmental disorder.

RESULTS

On the basis of the available evidence, there seem to be few qualitative differences between autistic disorder and Asperger's disorder.

CONCLUSION

There is currently insufficient evidence to establish the validity of Asperger's disorder as a syndrome distinct from high-functioning autism. The findings are consistent with the view that these disorders belong on an autism spectrum.

Autism and pervasive developmental disorders

The quantity and quality of research into autism and related conditions have increased dramatically in recent years. Consequently we selectively review key accomplishments and highlight directions for future research. More consistent approaches to diagnosis and more rigorous assessment methods have significantly advanced research, although the boundaries of the 'broader phenotype' remain to be defined and the validity of Asperger's disorder as a discrete syndrome remains controversial. Recent epidemiological studies have shown that Autism Spectrum Disorders are common, but there continues to be debate about the causes of the increase in the frequency with which autism is diagnosed. Psychological research has helped to develop new developmental models for the disorder and there have also been significant advances in the molecular genetics of autism and understanding of the underlying neurobiological processes. Areas important for future research include the study of autism as it first develops, i.e., in infants and very young children, and of specific processes (psychological and neurobiological) which underlie the disorder. Significant challenges lie ahead in evaluating the growing number of treatments for autism and in integrating the results of research into treatment and educational settings.

Diagnosis and epidemiology of autism spectrum disorders

In this paper, we give an overview of the diagnostic categories of autism and other pervasive developmental disorders (PDDs) and discuss the changes in the DSM classification system over the past 20 years. We describe each subtype of PDD, along with comorbid psychiatric conditions, assessment guidelines, and tools for diagnosis. The epidemiology of autism has generated much discussion and research; we report the most recent data, as well as recent findings about controversial issues purporting to cause the increased prevalence rate observed in the past decade. Finally, we discuss the prognosis for individuals with autism, indicating the challenges faced by patients, families, and professionals aiming to optimize their outcome.