Autistic Spectrum

The autism spectrum, also called autism spectrum disorders (ASD) or autism spectrum conditions (ASC), with the word autistic sometimes replacing autism, is a spectrum of psychological conditions characterized by widespread abnormalities of social interactions and communication, as well as severely restricted interests and highly repetitive behavior.

The three forms of ASD are:

1. Autism
2. Asperger syndrome
3. Pervasive Developmental Disorder Not Otherwise Specified (PDD-NOS), sometimes called atypical autism.

Autism forms the core of the autism spectrum disorders. Asperger syndrome is closest to autism in signs and likely causes; unlike autism, people with Asperger syndrome have no significant delay in language development. PDD-NOS is diagnosed when the criteria are not met for a more specific disorder. Some sources also include Rett syndrome and childhood disintegrative disorder, which share several signs with autism but may have unrelated causes; other sources combine ASD with these two conditions into the pervasive developmental disorders. According to the National Autistic Society of the United Kingdom, Pathological demand avoidance syndrome belongs and is increasingly being recognized as belonging to the autistic spectrum.

The terminology of autism can be bewildering. Autism, Asperger syndrome, and PDD-NOS are sometimes called the autistic disorders instead of ASD, whereas autism itself is often called autistic disorder, childhood autism, or infantile autism. Although the older term pervasive developmental disorder and the newer term autism spectrum disorder largely or entirely overlap, the former was intended to describe a specific set of diagnostic labels, whereas the latter refers to a postulated spectrum disorder linking various conditions. ASD, in turn, is a subset of the broader autism phenotype (BAP), which describes individuals who may not have ASD but do have autistic-like traits, such as avoiding eye contact.

The defining characteristics of autism spectrum disorders are qualitative impairments of social communication and interaction, along with restricted and repetitive activities and interests. Individual symptoms occur in the general population and appear not to associate highly, without a sharp line separating pathological severity from common traits. Other aspects of ASD, such as atypical eating, are also common but are not essential for diagnosis; they can affect the individual or the family.

An estimated 0.5% to 10% of individuals with ASD show unusual abilities, ranging from splinter skills such as the memorization of trivia to the extraordinarily rare talents of prodigious autistic savants.

Making and maintaining friendships often proves to be difficult for children with autism. For them, the quality of friendships, not the number of friends, predicts how lonely they are, despite the common belief that they prefer to be alone. Being on the autism spectrum does not keep children from understanding race and gender stereotypes in a society; like normal children they learn stereotypes by observing their parents’ actions.