MIND Institute research shows that onset of ASD deficits occur earlier than previously thought
A new study by the researcher group at UC Davis's MIND Institute reports that the onset of deficits in social communication and cognition occur between 6 and 18 months and represent a regression rather than a sudden loss of skills. This study did not rely on parent reports or home video, but rather carefully monitored the social behavior of infants from 6 to 18 months. The study suggests that parent reports of a sudden onset of deficits between 2 and 3 years is more than likely not the case, but rather represents a bias on the part of parent reporting of their children's behavior.
The study doen not blame parents, but instead suggests that parents simply tend to recall events by telescoping -- taking a distant event and bringing it into the present.
Google the study and let me know what you think.