The autism spectrum disorders are more common in the paediatric population than other better known disorders such as diabetes, spinal bifida, or Down syndrome. The earlier the disorder is diagnosed, the sooner the child can be helped through treatment interventions. Paediatricians, family physicians, daycare providers, teachers, and parents may initially dismiss signs of ASD, optimistically thinking the child is just a little slow and will “catch up.”
All children with ASD demonstrate deficits in 1) social interaction, 2) verbal and non-verbal communication, and 3) repetitive behaviours or interests. In addition, they will often have unusual responses to sensory experiences, such as certain sounds or the way objects look. Each of these symptoms runs the gamut from mild to severe. They will present in each child differently. For instance, a child may have little trouble learning to read but exhibit extremely poor social interaction. Each child will display communication, social, and behavioural patterns that are individual but fit into the overall diagnosis of ASD.
Children with ASD do not follow the typical patterns of child development. In some children, hints of future problems may be apparent from birth. In most cases, the problems in communication and social skills become more noticeable as the child lags further behind other children of the same age. Some children start off well enough. Often in the times between 12 and 36 months old, the differences in the way they react to people and other unusual behaviours become apparent. Some parents report the change as being sudden, and that their children start to reject people, act strangely, and lose language and social skills they had previously acquired. In other cases, there is a plateau, or leveling, of progress so that the difference between the child with autism and other children the same age becomes more noticeable.