Has the rate of autism truly increased in the last 50 years or so or is it just that the classification of autism has gotten broader and as such the prevalence seems larger?
“Got Questions?” is a new weekly feature on our blog to address the desire for scientific understanding in our community. We received over 3000 responses when we asked what science questions were on your mind. We answered a few here and the Autism Speaks Science staff will address the other themes we received in this weekly post.
In the last two decades reported autism prevalence has increased by more than 600% and a number of studies have sought to investigate the cause(s) of this dramatic increase in autism prevalence over time. Recent findings suggest that at least a portion of the increase in prevalence can be attributed to changes in diagnostic practices, earlier age of diagnosis, and increased awareness of autism over time. However, converging evidence also suggests that while these factors account for a portion of the increase, they cannot alone explain the dramatic rise in autism prevalence. Thus genetic and/or other environmental factors likely play a role and are the subject of numerous research projects currently supported by Autism Speaks.