The pair of papers by Swinkels and Dietz and colleagues report the first findings from an ambitious population screening study conducted in the Netherlands. This study pushes forward our knowledge in the clinically important area of early identification. I confess a personal interest in the topic and will make a few comments comparing and contrasting the findings of the present study with those from the UK group who conducted the CHAT (CHecklist for Autism in Toddlers) studies in the 1990s, of which I am a part (Baird et al.,
2000; Baron-Cohen, Allen, & Gillberg,
1992; Baron-Cohen et al.,
1996). The first notable contribution made by these papers is that they demonstrate that it is possible to prospectively identify children with autism spectrum disorders as young as 14 months of age. One finding that appears to be in common with the CHAT studies is that the sensitivity of the ESAT (Early Screening of Autistic Traits) is likely to be found to be fairly low, meaning that many cases are missed by the screen. One finding that is discrepant is the content of the most discriminating items at this age. In contrast to the social communication items measured by the CHAT at 18 months of age, the four-item ESAT at 14 months has items about varied play and sensitivity to noise. This may tell us something about the emergence of early symptoms in autism over the course of the second year of life. The other notable finding is the relatively high opt out from the study. As Dietz et al. discuss, this might reflect a reluctance at this early age for parents to consider that their child has a significant developmental problem. There will be limits to progress in early screening and identification and these papers help us understand where these limits might lie. …
