The Autistic Spectrum
Autism is more recently described along a spectrum. The spectrum is classified by behaviors and characteristics that may be normally distributed in the public, but some individuals inherit more or less autistic traits. Asperger’s Syndrome and PDD-NOS will be described here.
Asperger’s Syndrome: This condition was originally described by Hans Asperger in Vienna in 1944. Although Asperger was not aware of Leo Kanner’s work on autism, he did use the word autism (“autistic psychopathy”) to describe the social deficits he observed in a group of boys. His original description, in German, received little attention in the English-language literature until recent years. In people with Asperger’s Syndrome, deficits in social interaction and unusual responses to the environment, similar to those in autism, are observed. Unlike in autism, however, cognitive and communicative development are within the normal or near-normal range in the first years of life, and verbal skills are usually an area of relative strength. Idiosyncratic interests are common and may take the form of an unusual and/or highly circumscribed interest (e.g., in train schedules, snakes, the weather, deep-fry cookers, or telegraph pole insulators)
(http://www.med.yale.edu/chldstdy/autism/aspergers.html)
Pervasive Developmental Disorder, Not Otherwise Specified (PDD-NOS): is a ’subthreshold’ condition in which some – but not all – features of autism or another explicitly identified Pervasive Developmental Disorder are identified. PDD-NOS is often incorrectly referred to as simply “PDD.” The term PDD refers to the class of conditions to which autism belongs. PDD is NOT itself a diagnosis, while PDD-NOS IS a diagnosis. The term Pervasive Developmental Disorder – Not Otherwise Specified (PDD-NOS; also referred to as “atypical personality development,” “atypical PDD,” or “atypical autism”) is included in DSM-IV to encompass cases where there is marked impairment of social interaction, communication, and/or stereotyped behavior patterns or interest, but when full features for autism or another explicitly defined PDD are not met.
It should be emphasized that this ‘’subthreshold” category is thus defined implicitly, that is, no specific guidelines for diagnosis are provided. While deficits in peer relations and unusual sensitivities are typically noted, social skills are less impaired than in classical autism. The lack of definition(s) for this relatively heterogeneous group of children presents problems for research on this condition. The limited available evidence suggest that children with PDD-NOS probably come to professional attention rather later than is the case with autistic children, and that intellectual deficits are less common.
(http://www.med.yale.edu/chldstdy/autism/pddnos.html)
