You can actually diagnose Autism early. One way is to use behavioral markers that appear around 18 months with the absence of eye contact and connection to the primary caregiver. A lack of social games, a disconnection, absence of the typically seen social smile, arms held out to picked up and so on. The earlier Autism is diagnosed the sooner that intervention can be started. The sooner the intervention the better the outcome and prognosis for the future.
Early indicators are the limited interest in connection with others, limited interest in basic social interactions, lack of responsiveness to typical games of hide and seek, absence of a social smile, lack of imitation (verbal and non-verbal) and of course, lack of development of language and social communication in general. Recent statistics indicate that the disorder is present in one out of every 150 children by the time they turn eight years of age.