AUTISM : CURRENT ISSUES 26
This set of notes begins with some thoughts about the prevalence of autism and autistic spectrum disorder which, while apparenly increasing, may still reflect evolving diagnostic criteria as well as possible errors resulting from the use of a single ascertainment source.
There follows a description of recent genetic studies, with gradually emerging data about which genes are significant, and an implication that autism is not a single condition but the result of the merging of two separate genetic pathways.
The next section summarises the view that the pathology associated with Asperger Syndrome is a matter of social construction rather than of some inherent quality within this different (but not deviant) state.
The question of attentional style is then revisited ; and reference is made to the possible link between immune disorders and autism.
The final section discusses the viability of interventions designed to develop social interactive skills.
Over the recent past, estimates concerning the incidence of autism or autistic spectrum disorder (including Asperger Syndrome) have shown marked and frequent changes in an upward direction.
However, there is still debate whether the overall prevalence of autism has really increased, whether past prevalence has been under-recognised, or whether it is a matter of the widening of the definition of autism to include spectrum disorders and less severe symptomatology.
A recently published study in Atlanta, USA (Yeargin-Allsop 2003) has shown that the rate of autism was significantly higher in 1999 than what was reported in the 1980s and early 1990s. Typical rates before 1985 referred to 4 or 5 children per 10,000 ; but rates in both the USA and Britain have risen through 7-10 per 10,000 to 60+ per 10,000 in some studies (and in South-West Surrey, the Health Authority referred at the start of 2003 to a rate of 1 child in 69 !).
The study by Yeargin-Allsopp found a prevalence of 34 per 10,000 with a boy to girl ratio of 4:1 and comparable rates among white and black children.
It was suggested that the increased rate of recognised autism could reflect changes in diagnostic criteria, heightened public awareness and media coverage, and the addition of autism to those categories of need meriting special education services in the USA.
Meanwhile, the observed data confirmed the pattern within autism of a strong male predominance, cognitive impairment in around 66% of cases, and a relatively high rate (8%) of comorbid epilepsy.
It was noted that diagnosis was delayed in around 20% of cases, and that there was a high dependence on reports or expessions of concern from school staff, with the implication that one might be a little cautious about quoted incidence if the findings are based on anything but thorough and multiple ascertainment sources.
(This concern can be illustrated by the experience of the present writer - MJC - who was seeking secondary school students with ASD to act as participants in a study and was reassured by the staff in one school that several students could prove suitable candidates for inclusion, only for it to be found that none of the cited students had ever been formally identified with ASD).
On a tangential topic, albeit linked through the theme of possible data inaccuracy, one notes the work of Miller et al (2002) who examined the relative incidence of autism in relation to MMR vaccination in two studies.
Their examination of the numbers of cases based upon parental concerns compared with those involving observed regression in the children up to the age of 50 months led to the conclusion that there appears to be a parental recall bias when reporting the onset of regression in relation to the MMR immunisation in children who come to be identified with autism.
There is a risk that aetiological and prevalence studies could be affected if they are based on clinical histories obtained after the publication of an (unsubstantiated) hypothesis such as the impact of the MMR vaccination in "triggering" autism.
Current work reported in the American Journal of Human Genetics 72,3 2003, has led to the identification of at least one gene that may have a direct link with autism.
A gene on chromosome 15 appears to be involved in the distinctive autistic symptom of "insistence upon sameness".
The lead author of this work (Margaret Pericak-Vance) was interviwed for Medscape News (7 February 2003) and the initial theme highlighted how autism should not be viewed as some unitary condition but that clinically meaningful subgroups can be identified.
The ongoing studies were described as a matter of identifying families with two or more affected siblings and a statistical techniques described as " ordered subset analysis " allows for the quantification of similarities between families across different variables. Single traits (like insistence upon sameness) are distinguished and genetic similarities for each trait are sought ; and if there can be found a group of individuals with similar characteristics, the opportunity to determine the responsible gene is enhanced.
The gene on chromosome 15 appears to be involved in the regulation of neurotransmission ; and genetic links to other conditions, such as Angelman Syndrome or Prader-Willi Syndrome, are clustered in the same general region. Some children with these latter conditions also have autistic-like symptoms, especially repetitive behaviour.
Other chromosomes are being examined and there appears to be involvement of chromosomes 2 and 7 in different aspects of autism. For example, there has been a link established between phrase speech delay and chromosome 2.
In response to the question whether this all suggests that heredity is more critical than environment or whether one might still talk in terms of interaction between environmental factors and genetic predisposition, it was held that heredity and environment cannot be viewed separately. If there is a genetic predisposition which is triggered by some environmental event, one still needs to know the responsible gene or genes before being able to identify what are the environmental risks. It may be that subgroups who differ genetically are susceptible to different environmental risk factors.
Research described at the conference of the British Psychological Society (March 2003) and reported in the national press (Observer 16 March 2003 : ByLine R. McKie) has also indicated that autism is not a single psychological condition.
Researchers at the Institute of Psychiatry (Robert Plomin and Angelica Ronald) have produced evidence that autism is a combination of two separate "states", each controlled by different sets of genes. If the two occur together, then the child demonstrates symptoms which are characteristic of autism.
Diagnosis of autism depends, firstly, upon the social component in that, for example, there is a lack of theory of mind, and communications may be either limited or lacking in sensitivity ; and, secondly, upon the non-social component which would include symptoms of obsessionality or a preoccupation with detail.
In the past, it was assumed that such symptoms had a common source, but a large-scale twin study has indicated that these two sets of symptoms are acquired via different routes and different sets of genes.
Only when a person inherits extreme versions of both do they show the symptoms of full autism ; and the implication is for some acceleration in genetic studies now that it is recognised that a failure hitherto to pinpoint genes was based upon an inappropriate search for a common set of genes when there are actually two conditions involved and not one.
Asperger Syndrome : Making a Pathology out of a Difference
The basic question posed in the paper by Molloy and Vasil (2002) is whether Asperger Syndrome is actually a disorder, or a neurological difference that has been socially constructed as a disorder.
Asperger Syndrome can be traced to the work of Asperger who published his initial descriptive work in 1944, referring to children displaying normal intelligence and language development, but with significant deficits in social and communicative skills.
The main features of the condition (as described, for example, by Gillberg and Gillberg 1989) include ......
The authors describe contentious issues surrounding the evaluation of Asperger Syndrome, including the emphasis upon a medical model which can be counter-productive in that, once labelled, a child is defined according to the meaning attached to the label with resulting loss of individuality and lowered expectations.
A further concern is the apparent variability in the interpretation of diagnostic criteria, and inconsistency in agreeing which behaviours constitute necessary diagnostic features. This is complicated by the observations that the clinical presentation of the syndrome may change over time so that, as the child gets older, some diagnostic criteria will not be met.
An implication from the medical model is that any disorder or disability is a matter of biochemical changes and this logic suggests that the problems could be ended if there were some appropriate treatment.
However, the social model has it that how disorders and disabilities are classified, treated, and interpreted is socially constructed. In other words, the disability is not attached solely to the individual but is a multi-determined product of a diverse range of interpretations and practices (including school goals and assessments).
The example is given of town planning practices to demonstrate how an individual is more or less handicapped according to how much forethought is given to the impact of certain mobility problems and, therefore, how access to and between buildings is a matter of ease or difficulty.
Molloy and Vasil (op.cit) return to the question of whether Asperger Syndrome is an impairment or a difference by acknowledging that the children concerned need or demand a higher level of attention than other children and may show little regard for social norms, but they ask whether one can really speak of a social impairment that is totally within-child.
If the latter, the implication is that there is a clearly demarcated pattern of normal social behaviour into which all childhood behaviour falls, and that a failure to match this pattern may be regarded as an impairment.
A parent may find that it is frustrating to have a child who is focused to an obsessive degree on certain topics ; but, if that child develops into an adult with a high level of knowledge and expertise in a given field, one would hardly equate an obsessive-interest "style" as a disability.
Similarly, many of the children with Asperger Syndrome display some weaknesses in fine motor skills and require help to develop writing and recording skills; but these children frequently excel in the use of a computer and can quickly learn keyboard skills.
In seeking to understand the significance of the category of Asperger Syndrome, and whose interests is served by it, the authors argue that its "value" is in providing a category of special educational need.
A child's poor performance in school (against arbitrary and narrow criteria) is explained in terms of some problem in him or her and nothing to do with educational expectations and practices.
It is further pointed out that, in the case of many or most cases of Asperger Syndrome, the diagnoses appear to be precipitated by the entry of the children to educational settings.
The situational nature of "disability" is insufficiently appreciated.
An Asperger child who is obsessed with astronomy and who is able to pursue this specialisation with a tutor is less likely to display the frequency of difficulties or to seem as aberrant as the same child placed in a mainstream classroom.
The diagnostic category may also serve to provide a common and convenient category to allow different professionals to communicate with one another through language centred on needs perceived as intrinsic to the child while providing comfort to schools in seeking to maintain order and smooth functioning, to parents who seek to make sense of the child's behaviours, and to professionals who share the common goal of "normalising" the child (via endless interventions intended to fit the child into the system).
The authors conclude that (special) educational practice must extend beyond this deficit perspective and incorporate an appreciation of varying learning styles and aspirations.
The emphasis should move away from a rehabilitative approach which emphasises and reinforces the concept of individual disabilities to an approach which highlights the strengths and individuality of those known to have Asperger Syndrome.
Meanwhile, an adult with Asperger Syndrome (Willey 1999) is quoted as stating that she is not loooking for some cure for the syndrome, but a cure for the all-pervasive ill which forces people to compare themselves to some norm which is measured in absolute and unreachable standards.
Attention Style in Asperger Syndrome
Evidence exists for the frequent use of psychotropic drug use among individuals with higher functioning pervasive developmental disorders. It was found in studies reviewed by Schatz et al (2002) that 55% of the participants were receiving such medication, and psychostimulants were commonly cited.
This finding was followed up by these authors who felt that the issue of attention deficits among children with ASD warranted specific investigation especially as hyperactivity is often associated with Asperger Syndrome even if it is not in the list of diagnostic criteria set out in DSM-IV. Their review of studies also indicated that ADHD is the most commonly cited condition comorbid with Asperger Syndrome in children.
(Depression is most commonly comorbid with this syndrome in adolescents and adults).
The cognitive profile of Asperger children could reliably be distinguished from children with autism ; but the profiles of Asperger and attention deficit groups appeared very similar.
The authors set up their own study to determine whether their sample of children and young people with Asperger Syndrome (mean age 16) showed an enhanced number of ADHD symptoms compared to controls according to a standard assessment instrument.
A continuous performance test was used (the TOVA) in which one of two stimuli appear momentarily on a screen every two seconds, and the particpants have to press a button each time the target stimulus appears. Scores are recorded in terms of omissions, reacting when the wrong stimulus appears (commissions), and reaction time for, and variability of, correct responses.
Results indicated that participants with Asperger Syndrome were more likely to perform in the abnormal range. 63% gained scores suggestive of an attention deficit compared to only 25% of controls. Further, the Asperger sample showed much greater variability.
The discussion raised the issue whether ADHD is a psychiatric disorder that occurs alongside Asperger Syndrome, or whether the deficits intrinsic to Asperger Syndrome (such as odd socialization, obsessive thoughts, etc.) underlie secondary attention deficits.
This question is significant for the planning of interventions in that ADHD as a distinct but comorbid condition might effectively be treated with a psychostimulant ; but if the attentional symptoms are a result of the primary social deficits in Asperger, then the use of this medication is unlikely to be useful and might only expose the individual to the risk of further problems in the way of adverse side effects.
The conclusion emphasised the brief and initial nature of this study, and highlighted the need for further investigations to determine whether the performance of the Asperger sample reflects an actual attention deficit or an altered emotional or cognitive state which underlies the greater variability of responses compared to those of a control group.
The review of relevant studies completed by Krause et al (2002) describes how recent research into autistic aetiology has focused upon genetic mechanisms, pre-natal trauma, and brain function as well as immunological and neuro-chemical factors.
However, the results have been inconclusive for four basic reasons :
Nevertheless, various immune system abnormalities have been reported among children with ASD with the possible implication that immune factors are somehow involved in the initiation or evolution of the neurological disorders.
The primary function of the immune system is to differentiate self from foreign antigens and to clear the foreign antigens ; and malfunctioning in terms of response to self antigens may result in autoimmune disease, while defects in clearing foreign antigens may increase susceptibility to infection.
A familial clustering of autoimmune diseases is characteristic, suggesting the significance of genetic predisposition.
For example, Comi et al (1999) studied the families of children with autism and control families to evaluate the frequency of autoimmune disorders, and it was found that the mean number of disorders was greater in the families which had children with autism. The most common disorders were type1 diabetes, rheumatoid arthritis, hypothyroidism, and lupus.
The increase in familial autoimmune disorders was thought suggestive of a link in some genetically susceptible families between autoimmunity and autism.
Meanwhile, other studies reviewed by Krause et al (op.cit) led to their conclusion that there is circumstantial evidence to support an hypothesis that autoantibodies targeted at the CNS may be a causative factor for the development of ASD ... but this hypothesis requires more comprehensive investigation.
The authors continue to speculate in terms of the possible effect of neuro-receptor specific antibodies upon the CNS in triggering some of the structural anomalies seen in ASD, such as increased brain volume or altered frontal lobe and corpus callosum.
In respect of immune defects, it is reported that the reduced or skewed response to foreign antigens may induce anomalous functioning of immune cells. Such defects have been implicated in ASD.
Krause et al review a range of studies and highlight the inconsistency of findings commonly linked to the heterogeneity of participants, but acknowledge that they do, in general, point towards a dysregulated immune system in children with autism.
However, it is still not known whether these immune defects have some direct causal impact. Further, the impaired immune functions would increase susceptibility to infections, and persistent viral infections could lead to some altering of functioning of the immune system or of the CNS leading to some neurodevelopmental disorder, including ASD.
These hypotheses are described as plausible but as needing substantiation by thorough research evidence.
Finally, in regard to the issue of MMR and its alleged link with ASD, Krause et al join the consensus that there is compelling and much-replicated evidence for the safety of the MMR vaccination. However, they do comment that there may still be some public (parental) concern over this issue and there is a risk to public health from the failure to vaccinate ; and they suggest that a further and over-arching study may be desirable to settle once and for all these ongoing anxieties.
Facilitating Social Interaction
McConnell (2002) recognies the truism in stating that individuals with autism, children and adults, demonstrate delays, deficits, or atypical characteristics in the type or frequency of social relationships and interactions ; but his review of studies serves to show that the social irregularities of children with autism are amenable to intervention.
To begin with, McConnell sets out the evidence by which autistic characteristics and symptoms have been established ; and quotes the summary of Sigman and Ruskin (1999) to the effect that children with autism appear to be socially isolated primarily because of their own behaviour rather than a tendency in other people to avoid them or to fail to initiate interaction with them. The children with autism show very low rates of social initiations, nor do they show a high probability of responding to approaches from others.
However, existing evidence warrants two further conclusions. Firstly, it is not the case that children with autism as a whole fail to engage in any interactions with other children ; but secondly, social interactions for many autistic children are not favoured or sought-after activities. Isolate play, proximal onlooking, or challenging behaviours are more typically observed in the kind of free play settings where normally-developing children do make and maintain social relationships.
Behaviours that compete with social participation include repetitive and non-functional movements, stereotypic behaviours, and lack of proximity to peers. All such behaviours decrease the opportunity for social learning, and social skills remain (increasingly) immature. There is, in fact, evidence for an inverse correlation between a child's rate of self-stimulating or stereotypic behaviours, and social interaction ; and it is even argued that at least some children with autism find these behaviours the source of greater reinforcement than what emerges from social interaction, or that they engage in these behaviours specifically to avoid or reduce social interaction.
When it comes to determining which circumstances are linked to the greatest likelihood of eliciting social behaviours, McConnell's review highlights how there is a relationship between the nature of the activities offered and social "amenability" ..... for example, pre-school children with autism tend to engage in more social interaction when the activities available are ones which they prefer or when the activities and the materials are familiar and predictable. Further, social interaction may be the greater following periods in which the amount of environmental stimulation has been low.
Nevertheless, simply providing access for children with autism to typical and more socially competent peers without some other intervention is not sufficient to produce increases in social interaction even if there is some modest increase in the amount of initiations directed towards them. The benefit of access to an integrated playgroup is greater following a period of intensive intervention focused upon social interaction because of the opportunity for generalisation of the skills taught ; and social interaction on the part of the children with autism is directly associated with the number of typically-developing children in the playgroup who have been given explicit training and encouragement in terms of social interaction skills.
Additional evidence has indicated that the benefits are greater still when the children with autism are paired in pre-school settings with children of about their own age rather than with younger children who are perceived to be at a similar developmental level. These older children are found to be much more likely to initiate interaction and to respond positively to interactions received.
" Collateral skill interventions " are those in which children with autism demonstrate increases in social interaction as a function of training in other, apparently different, skills. For example, teaching generalized play skills to young children with marked autistic symptoms has been found to produce positive social interaction effects, especially in terms of peer responsiveness to the social initiations from the children with autism.
Games and activities selected as a best match to the kind of perseverative or obsessive behaviours observed in autism were also found to enhance social interaction when compared to more general play. Further, positive effects are the more likely when care is taken to match the skills being taught to the assessed developmental age level rather than to what is thought typical of play skills for the chronological age.
Child-specific interventions are instructional and reinforcement procedures specifically targeted to increasing the frequency and quality of socially-skilled behaviours. These interventions include social stories, or intensive reinforcement to prime social responding, or social skill training with adult-mediated reinforcement and prompting.
Such specific interventions, especially when the training is associated with a number of different interactive partners, have been found to produce generalised increases in social interaction for young children with autism.
The summary of available evidence suggests that there may be benefits from these techniques but the benefits will be limited if these interventions are implemented in isolation, possibly because the level of reinforcement accruing to the children with autism from the social interaction is quite limited. To be effective, there is a need for back-up reinforcers and explicit work to enhance generalisation.
Peer-mediated procedures are those in which social skill training and prompts/praise are provided to the other children in a group setting with a view to influencing the social interactions and skills of the children with autism. For example, peer-mediated interventions encouraging peers to direct social behaviours towards the autistic individuals have been found to be effective in increasing communicative interactions and verbal labelling of objects.
Such methods have also been found to be effective in home settings where siblings of the children with autism are taught to increase rates of prompts and praise in respect of several targeted behaviours to their brothers or sisters with autism, with positive outcomes in terms of the specific behaviours and of enhanced social interaction.
However, what matters is the need consistently to update the training of peers and siblings, or to provide new training as peer groups change.
In his concluding summary, McConnell holds that accumulating evidence does show that, under at least some conditions, children with autism can benefit reliably from social interaction skill interventions, and that these interactions can be taught and learned.
However, there remain questions about the effects of different strategies and of different permutations, and about long term generalisations.
To date, most research is a matter of " technique building " and there has been little opportunity for assessing the impact of interventions outside a setting such as a pre-school classroom involving the teachers as facilitators of a programme and classmates as interactive partners. Further, innovations have yet to receive significant peer-reviewed empirical support.
Nevertheless, it is argued that there is developing sufficient knowledge about promoting social interactive skills that they should be a target for any educational intervention programme (within a framework of action research to continue to build data about what constitutes effective practice under what conditions).
M.J.Connor March 2003
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Krause I., He X., Gershwin M., and Shoenfeld Y. 2002 Brief report : immune factors in autism. Journal of Autism and Developmental Disorders 32(4) 337-345
McConnell S. 2002 Interventions to facilitate social interaction for young chldren with autism. Journal of Autism and Developmental Disorders 32(5) 351-372
Miller E. 2002 Summary of work reported in Medscape Medical News (31 December 2002) Original article in the Archives of Disease in Childhood 87 493-494
Molloy H. and Vasil L. 2002 The social construction of Asperger Syndrome. Disability and Society 6 659-669
Pericak-Vance M. 2003 Summary of interview conducted for Medscape Medical News (7 February 2003) Original article in the American Journal of Human Genetics 72(3)
Schatz A., Weimer A., and Trauner D. 2002 Brief report : attention differences in Asperger Syndrome. Journal of Autism and Developmental Disorders 32(4) 333-336
Sigman M. and Ruskin E. 1999 Continuity and change in the social competence of children with autism, Down Syndrome, and developmental delays. Monographs of the Society for Research in Child Development 64 1-130
Willey L. 1999 Pretending to be Normal. London : Kingsley
Yeargin-Allsopp 2003 Summary of work reported in Medscape Medical News (7 February 2003) Original article in the Journal of the American Medical Association 289 49-55
© Mike Connor 2003.
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