What are autism spectrum disorders?

Autism spectrum disorders (ASDs) include Autistic Disorder, Asperger's Disorder and Pervasive Developmental Disorder – Not Otherwise Specified. These related conditions represent a group of neuro-developmental disorders characterised by difficulties in reciprocal social interaction, verbal and non-verbal communication, and a restricted repertoire of activities and interests combined with repetitive and stereotyped behaviour. Some people with an ASD may also be either over- or under-sensitive to sensory stimuli (sound, touch, taste, smell and visual). Many report that they find the world a confusing place to understand. In very young children, autism manifests in a reduction in key behaviours such as lack of or reduced eye contact, emotional expression, orientation to name, joint attention and imitation. These lead to difficulty in learning social routines (clapping, waving, peek-a-boo), delayed and/or deficient language development, under-developed play skills (especially pretend play), and in some children, unusual sensory behaviours (excessive mouthing, aversion to touch, odd body movements). These behaviours usually emerge very gradually, sometimes not until the second year of life. ASDs are lifelong conditions and there is no known cure.

Prevalence of Autism Spectrum Disorders

As late as in the early 1990s autism was believed to be a ‘rare’ condition, affecting about 4 children in every 10,000. The recognition that AD, PDD-NOS and AspD may all belong to a spectrum of similar disorders resulted in the more inclusive category of ASDs, which accounts for part of the increase in prevalence, 1 in 150 children, reported in 2000. Since then there has been a further increase, to approximately 1 in 100 children (or 1%), which is consistent with our latest research. Other countries have also reported similar figures, although in the US the Center for Disease Control estimated recently that the prevalence is even higher, 1 in 88 children. Some of the increase since the 1990s is due to the way children are identified and diagnosed with more sensitive assessments, but there also seems to be a ‘real’ increase in the number of children affected by the disorder. The causes of this ‘real’ increase are not known. ASDs are approximately four times more common amongst boys than amongst girls.

Causes of Autism Spectrum Disorders

The underlying physiological causes of ASDs are currently not known. There is, however, little doubt as to their genetic basis which cause changes in the pattern of brain development and function. Previous research has shown that ASDs are not caused by inadequate parenting, vaccinations or other medical interventions. Being a genetic condition means that ASDs tend, sometimes, to run in families and there is an increased chance (about 20%) of having another child with an ASD if there is already a child with an ASD in the family. ASDs are often associated with other conditions, including Fragile-X Syndrome, ADHD and/or developmental delay/intellectual disability.

Treatment of Autism Spectrum Disorders

The only treatments for an ASD that have been shown to be consistently effective are early intensive behavioural interventions (EIBI). However, the prerequisite for EIBI is early diagnosis, which is difficult as there are no obvious physical or biological signs of these disorders and no simple screening tests, such as a blood test. Therefore a diagnosis can only be based on the child’s developmental history and observation of behavioural symptoms. We, at OTARC, are very keen to facilitate early diagnosis so that both child and family are able to access support as early as possible. We have undertaken a considerable amount of research in this area and have shown that early childhood professionals, such as Maternal and Child Health Nurses and Paediatricians, can be trained to reliably detect early behavioural signs of ASDs in children aged between 12 and 18 months (Barbaro and Dissanayake, 2010). Current diagnostic tools allow a trained professional to reliably diagnose an ASD as early as 18 months of age, and work is continuing to develop tools for an even earlier diagnosis. The Early Diagnostic Clinic for ASDs provides a diagnostic service for children up to the age of 36 months.

Early intervention seeks to address the child’s behavioural, social and communication difficulties with various programs, the most effective of which include some form of Applied Behaviour Analysis. The Early Start Denver Model (Rogers and Dawson, 2010) is one of these programs. Apart from building on some of the ABA principles, it is a developmental, behavioural and relationship-based intervention program, designed for use within naturalistic interactions with everyday activities. It is the method of intervention used at the Victorian Autism Specific Early Learning and Care Centre: The Margot Prior Wing at La Trobe University associated with OTARC.

Apart from early intervention, people with an ASD and their families usually need lifelong support, especially those with the more severe form of ASD, Autistic Disorder. This support often covers educational (children with an ASD learn differently to typical children), social communication (interaction with others remains a challenge), speech and language pathology, and psychiatric support (people with an ASD often suffer anxiety).

Commonly used acronyms

AD: Autistic Disorder
ADHD/ADD: Attention Deficit Hyperactivity Disorder/Attention Deficit Disorder
ASD: Autism Spectrum Disorder
ASELCC: Autism Specific Early Learning and Care Centre
AspD: Asperger’s Disorder
DD: Developmental Delay
DQ: Developmental Quotient
DSM-IV / DSM-IV-TR / DSM-V: Diagnostic and Statistical Manual of Mental Disorders-4th edition / 4th edition – Text Revision / 5th edition
ESDM: Early Start Denver Model
HFA: High-functioning autism
ID: Intellectual Disability
IQ: Intelligence Quotient
LD: Language Delay
OTARC: Olga Tennison Autism Research Centre
PDD-NOS: Pervasive Developmental Disorder – Not Otherwise Specified
TD: Typical development/typically developing

More information

For more information about autism spectrum disorders and resources for individuals and families affected by autism spectrum disorders, visit:

References

Barbaro, J., & Dissanayake, C. (2010). Prospective identification of Autism Spectrum Disorders in infancy and toddlerhood using developmental surveillance: The Social Attention and Communication Study. Journal of Developmental and Behavioral Paediatrics, 31, 376 –385.

Rogers, S.J. & Dawson, G. (2010). Early Start Denver Model for Young Children with Autism: Promoting Language, Learning, and Engagement. New York: The Guilford Press.