Nosology and diagnosis of Asperger's syndrome

The autism spectrum disorders (ASD) have generated great interest among clinicians and researchers. Once considered rare, recent epidemiological data now suggests rates of up to 1 in 150 people. One of the most frequent of the ASD, Asperger's syndrome (AS), has been known as a disorder for as long as autism, which is easily the most visible of this group of conditions. Growing attention to and popularity of studying AS have made the nosology and diagnosis of the disorder a topic of growing concern in recent years. The purpose of this paper is to present an up-to-date analysis of the syndrome and the likelihood that it is actually a disorder distinct from high-functioning autism (HFA). This argument about how to diagnose people, either AS or HFA, hinges largely on the debate about whether distinct symptom patterns exist between AS and HFA and if AS can be reliably differentiated from HFA. A discussion of this topic, trends in research, and where the data appears to be leading diagnosticians is also presented, as well as research areas requiring further attention.