My major concern with the proposed DSM-5 definition and diagnostic criteria for ASD is the decision to consolidate the subtypes of DSM-IV PDDs within the overarching category of ASD. This change reflects the thought that the symptoms of these subtypes represent a continuum from mild to severe, rather than being distinct disorders. In that case, I believe the term “autism continuum disorder” would be more appropriate than “autism spectrum disorder.” On the other hand, in supporting the proposed DSM-5 ASD criteria, one of the key members of the work group, Dr. Francesca Happé (5), stated, “To date there is not a robust, replicated body of evidence to support the diagnostic distinction.” However, the literature review provided by Dr. Happé showed that about equal numbers of studies (about five studies each) reported “no difference” and a “significant difference” between autistic disorder and Asperger’s disorder according to the different variables examined. My own recent review of literature (6) showed that about three times as many studies showed a significant difference as showed no difference between the two disorders. Thus, the opponents of DSM-5 ASD can also claim that to date there is not a robust, replicated body of evidence to support the concept of an “autism continuum” (i.e., DSM-5 ASD).