The trouble with autism: Delays in early identification and diagnosis

A significant proportion of the troubled children that come to the attention of psychologists are those struggling with the social, behavioural and cognitive difficulties associated with an Autism Spectrum Disorder. Autism Spectrum Disorders (ASDs) are a complex body of neurodevelopmental disorders which affect approximately one per cent of children. They are characterised by difficulties in the core areas of social communication and language, accompanied by restricted and repetitive behaviours and interests. These and other associated difficulties, like anxiety and sleep disorders, can make everyday life challenging for affected children and their families.

Benefits of early identification and diagnosis

One of the first challenges faced by children with an ASD and their families is not necessarily the disability itself, but that these complex disorders are not identified in a timely manner, leading to delays in diagnosis and ensuing distress in the family. Most importantly, however, late identification of ASD leads to unnecessary delays in early intervention, preventing the realisation of positive developmental outcomes. Early and accurate diagnosis saves countless families the financial and emotional cost of traversing numerous services, usually for many years, in the hope of identifying their child’s disorder. It also enables families to access appropriate interventions for their child to begin addressing his/her specific early developmental and educational needs. The earlier this is possible, the more likely the child will be able to make the necessary developmental gains. Indeed, early identification, diagnosis and intervention provides the greatest opportunity for better long-term outcomes, including greater independence, decreased burden on families and the community as a whole, and better quality of life for individuals and their families.

Age of onset of ASD

In Australia, as elsewhere, the mean age of diagnosis for those with an ASD is approximately four years of age. Indeed, many affected individuals are not identified until school age and beyond. This latter outcome is especially common amongst children referred to as having high-functioning autism or Asperger’s disorder, who typically are cognitively able and develop language at an age appropriate time. Nonetheless, even amongst these so called ‘high-functioning’ individuals, telling signs are available from early in development, usually prior to the onset of language.

We now understand that the onset of autism symptoms is variable during the first two years of life, with signs evident in some children from birth, while others may appear to be developing typically but then fail to progress, and yet others who may lose some of the skills already developed. This apparent slowing and/or regression in development is usually seen in the second year of life between 15 to 24 months of age. The variable pattern of onset means that one-off screening for signs of ASD at a given age is not a suitable approach to identification, and has typically resulted in poor sensitivity (Barbaro & Dissanayake, 2009). Rather, a developmental surveillance approach is advocated during the second year of life on the basis of promising results from the Social Attention and Communication Study (SACS; Barbaro & Dissanayake, 2010).

Developmental surveillance

The developmental surveillance approach was adopted in the SACS, which was designed to prospectively identify infants who have an ASD through the universal Victorian Maternal and Child Health (MCH) service via their routine assessments during the first two years of life. The early phenotype of autism is marked by an absence of key behaviours important in children’s social communicative development. Two hundred and forty one MCH nurses were trained to monitor infants’ development on these key items (the absence of which is indicative of an ASD; see boxed information) during their routine check-ups at 8, 12, 18 and 24 months. Over 20,000 children seen by the MCH nurses were monitored for social attention and communication behaviours such as pointing, waving, imitation, eye contact, response to name and social smiles. Importantly, the behaviours monitored at each age differed, taking into account the development of these key skills (Barbaro & Dissanayake,
in press).

The training of nurses was undertaken at each of 17 Local Government Areas during a 2.5 hour session where nurses were trained on the early autism phenotype and the coupling of the first signs that are indicative of ASD development at each age. This training was well received with evaluations at the time of training, six months after and at the conclusion of the study showing excellent results (Barbaro, Dissanayake & Ridgway, 2011). The success of the SACS in prospectively identifying infants with an ASD via their MCH checkups promotes the utility of the training undertaken by the MCH nurses.

From 12 months onwards, infants who showed an absence of the key behaviours were referred by their MCH nurse to the team at La Trobe University for a thorough developmental assessment, and then followed up at 6-monthly intervals until 24 months of age, at which time they received a standardised assessment for autism. Eighty-one per cent of the children referred by the nurses met criteria for an ASD, with only one typically developing child being incorrectly referred. The remaining children had either a developmental and/or language delay. A follow-up study of all referred children at preschool age indicated high diagnostic stability (86%; Barbaro & Dissanayake, 2012).

Early Diagnostic Clinic for ASD

The success of the SACS in prospectively identifying infants and toddlers via routine developmental surveillance within a universal service, and the accuracy of early clinical diagnoses of ASDs at 24 months, led to the establishment of Australia’s first Early Diagnostic Clinic (EDC) for Autism Spectrum Disorders, which focuses on children under the age of three years. Funded by the RE Ross Trust, the EDC was established in July 2011, and is an initiative of the Olga Tennison Autism Research Centre at La Trobe University. Also at La Trobe, the Victorian Autism Specific Early Leaning and Care Centre: The Margot Prior Wing of the La Trobe Community Children’s Centre was established in partnership with the Federal Government and the Royal Children’s Hospital in 2010. Recent data from the first cohort of 20 children with an ASD aged two to five years indicate that while all children made significant developmental gains over the course of one year of intervention, those who were younger when they began intervention made the best progress over this time (Vivanti, Dissanayake & the Victoria ASELCC Team, 2012). These data speak to the importance of accessing intervention early in development.

Conclusion

In the absence of known biological causes of ASDs and available cures, the best approach to treatment is to minimise the effects of these disorders on the developing child. This is only possible if we can firstly identify and diagnose ASDs early in development and, secondly, intervene as soon as there are warning signs so that the interventions may target the developmental antecedents of ASDs. Evidence-based interventions that are contextually relevant and that target risk and protective factors can serve to prevent the full blown manifestation of ASDs from developing, at least in some cases.

The importance of education about the early characteristics of ASD and the value of early identification, diagnosis and intervention cannot be underestimated. Sadly, constraints on funding and the concomitant availability of suitable services for those affected by ASDs means that many of the achievable gains are not being realised. However, in understanding and promoting knowledge on the early phenotype of ASDs, and by regularly monitoring all children for early signs of ASDs, we can begin to promote early identification and diagnosis. Indeed, the newly published Autism Diagnostic and Observation Schedule 2, a gold standard diagnostic assessment tool for ASD, has a new Toddler Module which allows for the diagnostic assessment of children with ASD as young as 12 months.

The author can be contacted at [email protected].