Clinical evidence that Asperger's disorder is a mild form of autism

Objective: The aim of this study is to obtain clinical evidence to test the hypothesis that Asperger's disorder (AD) is a mild form of autism (AU). Method: A 78-item Likert scale (the RAADS) was administered to 25 adults with AD and 19 with AU (ages, 18-65 years) to assess presence, type, and duration of symptoms. Results: The following results were found: (a) subjects with AD and AU have similar symptoms throughout adulthood (responses to 72 of 78 questions were not significantly different); (b) subjects with AD had a significantly fewer total number of symptoms; (c) subjects with AD reported nonsignificantly fewer symptoms in the DSM-V-TR domainsof social interaction and repetitive patterns of behavior; and (d) subjects with AD had significantly fewer symptoms in the cominunication domain. Conclusions: The data support the hypothesis that AD is a mild form of AU, and that they share a common etiology and developmental neuropathology. It appears warranted in future diagnostic manuals to incorporate AU and AD into I diagnostic category such as, Autism Spectrum Disorder, (with modifiers, severe, moderate, mild, atypical, and Asperger's type). (c) 2008 Elsevier Inc. All rights reserved.