Katherine D. Tsatsanis

What is Known About Autism

Autism is a neurodevelopmental disorder of genetic origins, with a heritability of about 90%. Autistic disorder is classed within the broad domain of pervasive developmental disorders (PDD) that also includes Rett syndrome, childhood disintegrative disorder, Asperger syndrome, and PDD not otherwise specified (PDD-NOS). Prevalence estimates suggest a rate of 0.1–0.2% for autism and 0.6% for the range of PDD disorders. There is considerable phenotypic heterogeneity within this class of disorders as well as continued debate regarding their clinical boundaries. Autism is the prototypical PDD, and is characterized by impairments in three core domains: social interaction, language development, and patterns of behavior (restricted and stereotyped). Clinical pattern and severity of impairment vary along these dimensions, and the level of cognitive functioning of individuals with autism spans the entire range, from profound mental retardation to superior intellect.There is no single biological or clinical marker for autism, nor is it expected that a single gene is responsible for its expression; as many as 15+ genes may be involved. However, environmental influences are also important, as concordance in monozygotic twins is less than 100% and the phenotypic expression of the disorder varies widely, even within monozygotic twins. Multiple susceptibility factors are being explored using varied methodologies, including genome-wide linkage studies, and family- and case-control candidate gene association studies. This paper reviews what is currently known about the genetic and environmental risk factors, neuropathology, and psychopharmacology of autism. Discussion of genetic factors focuses on the findings from linkage and association studies, the results of which have implicated the involvement of nearly every chromosome in the human genome. However, the most consistently replicated linkage findings have been on chromosome 7q, 2q, and 15q. The positive associations from candidate gene studies are largely unreplicated, with the possible exceptions of the GABRB3 and serotonin transporter genes.No single region of the brain or pathophysiological mechanism has yet been identified as being associated with autism. Postmortem findings, animal models, and neuroimaging studies have focused on the cerebellum, frontal cortex, hippocampus, and especially the amygdala. The cerebello-thalamo-cortical circuit may also be influential in autism. There is evidence that overall brain size is increased in some individuals with autism.Presently there are no drugs that produce major improvements in the core social or pragmatic language deficits in autism, although several have limited effects on associated behavioral features.The application of new techniques in autism research is being proposed, including the investigation of abnormal regulation of gene expression, proteomics, and the use of MRI and postmortem analysis of the brain.

Syndrome of Nonverbal Learning Disabilities: Psycholinguistic Assets and Deficits.

It is usually observed that, following an initial delay in speech acquisition, children with the syndrome of nonverbal learning disabilities (NLD) go on to exhibit well-developed speech and language skills. There is, however, comparatively little appreciation of the full extent of their deficits in linguistic skills. The NLD syndrome is so named because all of its clinical presentations are thought to arise from deficits that arc primarily nonverbal in nature. The psycholinguistic dimensions of NLD that constitute integral features of its developmental picture, are thought to arise because of the primary, secondary, and tertiary assets and deficits outlined in a developmental model that we have developed (Rourke, 1989,1995a). It is clear that a superficial consideration of the speech and language of children with NLD would be misleading; there is a great deal to be understood through close examination of the qualitative aspects of their linguistic skills. Our discussion of the psycholinguistic dimensions of NLD is presented within the context of a framework developed by Bloom (1988) who has described language as consisting of the three basic dimensions of form, content, and use.

Concurrent Validity and Classification Accuracy of the Leiter and Leiter-R in Low Functioning Children with Autism.

The concurrent validity of the Leiter International Performance Scale (Leiter) and Leiter International Performance Scale–Revised (Leiter-R) was examined in a sample of children with autism who could not be assessed with more traditional measures of intelligence (e.g., the Wechsler scales). The sample consisted of 26 children ranging in age from 4 to 16 years. The correlation between the Leiter scales was high (r = .87), and there was a difference of 3.7 points between the two mean scores, nonsignificant at both statistical and clinical levels. However, significant intraindividual discrepancies were present in 10 cases, 2 of which were both large (24 and 36 points) and clinically meaningful. The mean profile of performance on Leiter-R subtests is also presented for this sample of children with autism, to allow for comparison with other groups. Based on the results of this initial evaluation, together with the current normative data, good psychometric properties, and availability of global and subtest scores with the Leiter-R, the instrument is generally recommended for use with children with autism. However, because of changes in the design of the Leiter-R, there may be greater clinical success with the original Leiter for those children who are very low functioning and severely affected, particularly younger children.

Outcome research in Asperger syndrome and autism

This article presents findings from the outcome literature on autism, Asperger syndrome (AS), and related disorders. The discussion of outcome principally focuses on life adaptation, but also considers outcome in AS in relationship to other diagnostic groups and across time. The current research in this area is neither substantial nor systematic. Thus, in this examination of the literature, the goal is to highlight salient findings, but also to put forward questions that might direct meaningful research in this area for the future and to consider implications for treatment.

Psychosocial Dimensions of Learning Disabilities External Validation and Relationship with Age and Academic Functioning

This study was designed to assess the following in a group of 152 children with learning disabilities between the ages of 7 and 13 years: (a) the relationships between age and psychosocial functioning; (b) the relationships among psychosocial functioning, cognitive abilities, and academic achievement; and (c) the external validity of statistically derived psychosocial subtypes. Participants were assigned to one of seven psychosocial subtypes on the basis of a profile-matching algorithm. Overall, the findings suggested no increase in psychopathology with advancing age. In addition, clear relationships were found between academic achievement patterns and personality subtypes. Finally, the subtypes could be distinguished on the basis of a behavior problem checklist not used for the construction of the subtypes.

Managing Complexity: Impact of Organization and Processing Style on Nonverbal Memory in Autism Spectrum Disorders

The contributions of cognitive style and organization to processing and recalling a complex novel stimulus were examined by comparing the Rey Osterrieth Complex Figure (ROCF) test performance of children, adolescents, and adults with ASD to clinical controls (CC) and non-impaired controls (NC) using the Developmental Scoring System. The ROCF task involves a complex structure with strong organizational or integrative processing demands. The individuals with ASD relied on a predominantly part-oriented strategy to cope with the complexity of the task and did not make the typical developmental shift to a configurational approach. Both processing style and organization (whether pieces of information were perceived as connected to one another in a meaningful way) contributed to structural recall in the ASD group.

The Role of Adaptive Behavior in Evidence-Based Practices for ASD: Translating Intervention into Functional Success

The main diagnostic features of autism spectrum disorders (ASD) are defined in terms of qualitative impairments in social interaction, communication, and a pattern of restricted interests or repetitive behaviors. However, the particular constellation of symptoms, number, frequency, and severity differs from individual to individual. For some, an end goal in the treatment of autism spectrum disorders, whether stated explicitly or not, is to reduce autistic symptomatology and “cure” the disorder. One positive step in the discourse around treatment for ASD is a change in focus from symptom expression to measured changes in adaptive functioning. From this perspective, the intransigence of the diagnosis is not an indication of lack of success of a treatment model or educational program; rather, an emphasis is placed on functional outcomes such as helping people with ASD attend school in the least restrictive environment, communicate with family and peers, enjoy leisure activities with others, attend to their daily living needs (e.g., toileting, washing, dressing, eating, and cleaning), regulate emotions and behavior, and establish and maintain relationships with others.