Autism spectrum disorders

1 Mar 2011

The earlier that children with an Autism Spectrum Disorder (ASD) receive referral, diagnosis and intervention, the better the long-term results are for those children and their families (Barbaro & Dissanyake, 2009; Wiggins et al., 2006; Mandell et al., 2005). Primary health care professionals, such as child and family health nurses and GPs, can listen to parent concerns and be alert to the signs of developmental delay in infancy and early childhood to facilitate early referral and diagnosis. Indeed, Barbaro & Dissanayake state that primary health care professionals, given their extensive knowledge and training on developmental milestones, are the best placed – and most expert – to observe young children’s development and to identify early signs of ASDs (2010, p. 377).


ASD is the term used to refer to three types of developmental disorder: Autism, Asperger’s Syndrome and Pervasive Developmental Disorder – Not Otherwise Specified (PDD-NOS).

A diagnosis of one of the three indicates a developmental deficit of varying severity in the areas of:

  • communication
  • social skills and/or
  • behaviour

No two children with an ASD are the same, as they each have varying degrees of developmental deficit in the above three areas. This is why the term ‘spectrum’ is used when describing the disorder. In this article we will use the term ASD when referring to the all three of the disorders. Diagnoses of ASD have increased markedly since the 1990s. Prior to this, children were generally diagnosed with Global Developmental Delay or intellectual disability. Williams et al. (2008) found that:

  • The current rate of prevalence in Australia is estimated at 1 in 160.
  • Rates of diagnosis vary by state and territory due to differences in the way a diagnosis can be reached.
  • Australian data show that about four boys are diagnosed with ASD for every one girl. The cause of ASD is not known, but is thought to be a combination of genetic and environmental factors. It is not caused by anything the family does or does not do.

Despite the recognition that signs of ASD can appear in infancy, one study from America found that the average age of diagnosis is around three or four years old (Mandell et al., 2005). In specialist centres, diagnoses can be made for some children as early as 24 months, and rarely earlier. Significant research is being done to try and reduce the average age of diagnosis as this may lead to an earlier intervention. In turn, earlier intervention could help improve developmental outcomes for children and their families and lessen the long-term impact of an ASD for an individual child (Barbaro & Dissanyake, 2009).

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