LAUSR

Developmental disorders are characterised by an onset during infancy or early childhood of impairment or delay in the development of functions that are strongly related to biological maturation of the central nervous system. They typically follow a steady course without remissions and relapses (except in autism spectrum disorders, where a phase of regression in communication skills may be evident). Areas of impaired functioning include the physical, speech or language, social, adaptive and cognitive domains. More recently, in The Diagnostic and Statistical Manual of Mental Disorders, 5th edition and International Classification of Diseases, 11th edition (ICD-11) the neurodevelopmental category has been broadened to include Intellectual Disability. The estimated prevalence of developmental disorders ranges from 14 to 17%, with the prevalence of Global Developmental Delay (delays in 2 or more developmental domains) estimated to be between 1 and 3% of children aged less than five years. It is likely that variations in diagnostic criteria, changes to criteria over time, and the strong likelihood of co-occurring developmental conditions have all contributed to variations in prevalence estimates for these disorders. Current estimates suggest that approximately 42 000 of the estimated 300 000 children born each year in Australia will experience developmental disorders. Reducing the impact of developmental disorders at a population-level poses a major challenge for child health services in Australia. Three broad approaches can be used to achieve this goal. Firstly, universal interventions can be provided to all children, irrespective of their risk status or the presence of health problems at the time a universal intervention is delivered (e.g. all children in a geographical region). Secondly, targeted interventions comprised of selective and/or indicated interventions can be utilised. Selective interventions focus on children who have an increased risk of developmental problems as a result of exposure to known risk factors. Indicated interventions focus on children who have early symptoms of developmental problems. Finally, clinical interventions can be provided to children who have been assessed and identified as having developmental problems that require direct face-to-face help from health professionals. Currently, health and education services primarily use targeted and clinical interventions to help children with developmental disorders. This is based on evidence that systems of coordinated care that promote children’s age-appropriate development during their early years can be effective in helping the developmental progress of infants and toddlers. If such programmes could be widely and successfully implemented prior to school commencement, they have the potential to provide important benefits by reducing the health, financial and social costs of supporting individuals with developmental disorders during their adult years. The advantage of targeted and clinical approaches is that they do not solely rely on parental judgement about children’s developmental progress or active help-seeking by parents. They are, however, challenged by the difficulty of accurately identifying children with developmental disorders, given the variability in age when children achieve functional skills in relevant domains. Furthermore, substantial resources are required to screen large numbers of children to identify those with existing problems or high risk for future problems. As a result, while the small percentage of children with severe developmental disability are typically identified at a young age (often outside of normal screening programmes), the majority of those with less severe problems are not identified until school entry by which time the impact of their disorders is much greater.