Evolution of Autism

From 1942 to Present Day

Classic Autism was first recognized in 1942 by Dr. Leo Kanner at Johns Hopkins Hospital. ASD has been recognized as a medical disorder only in modern times, but there are many historical accounts indicating that autism existed long before the 20th century.

The possible causes of autism are still far from understood. At one time, autism was mistakenly thought to be caused by “cold” parenting; later it was wrongly classified as childhood psychosis or a type of childhood schizophrenia.

Parenting styles do not cause children to have ASDs. Today, research around the world focuses on possible causes, such as genetics, differences in biological brain function, pre- and post-natal brain development, environmental factors, viral infections and immune responses and deficiencies. Many possible causes are being investigated.

When speaking of ASDs, most people are referring to their historical (prior to DSM-5) names:

  • Autistic Disorder (also called “autism” or “classic autism” or “AD”)
  • PDD-NOS (Pervasive Developmental Disorder – Not Otherwise Specified)
  • Asperger’s Syndrome (also called “AS”, “Asperger’s” or “Asperger’s Disorder”)

Pervasive Developmental Disorder – Not Otherwise Specified (PDD-NOS)

A diagnosis of PDD-NOS was made when the strict criteria for Autism and Asperger’s Syndrome were not met.  The person would still have had problems with social relationships, impaired communication and repetitive behaviours.  Usually people with PDD-NOS also had some language delays.

How is Asperger Syndrome (AS) Different from Classic Autism?

AS was first identified by Dr. Hans Asperger in Austria in 1944, but his work did not find its way into the American Psychiatric Association’s Diagnostic Statistical Manual until 1994. After years of misdiagnosis or lack of diagnosis, there has recently been more recognition of AS and also a very noticeable increase in the number of people diagnosed with AS in North America.

  • AS is often considered to be a type of “high-functioning” autism. There is some clinical controversy about whether AS is a milder form of Autism Disorder or a distinct disorder.
  • The term “high-functioning” can be misleading in that it doesn’t necessarily translate to lower needs.
  • AS tends to be recognized and diagnosed later in life, usually after 3 years of age, when a child is already in school. AS can also be diagnosed much later in teens and adults.
  • Unspoken rules of reciprocal social interaction and communication which most of us take for granted, such as body language, social distance, facial expressions and abstract speech or humour, may be very hard for an individual with AS to understand.
  • Many people with AS want to develop friendships but lack the social skills to begin and/or maintain a friendship. Inability to reciprocate, to listen to another person’s thoughts or understand their feelings can make it hard to make and/or keep friends.
  • People with AS may interpret things very literally and be quite rigid in terms of following rules and habits. Strict adherence to patterns of behaviour or rituals is common and activities and interests may be limited. Sudden changes in routine, setting or expectations can cause great anxiety. Sometimes large crowds or dealing with strangers can be upsetting as well.
  • Development of learning and cognition is not usually delayed in AS and can be above average in terms of cognitive ability. Speech may be stilted but people with AS do not have language delays and may read very well or have very large vocabularies for their age. Still, they will struggle with the social uses of language and non-verbal communication. Individual needs assessment is key because functional evaluation may be more relevant than cognitive evaluation.
  • Some people with AS have amazing rote memories. Coupled with an obsessive interest and/or unusual creativity, this can lead to great expertise and achievement if there is enough encouragement and opportunity to develop particular skills. History is full of examples of high achieving thinkers, mathematicians and musicians who are believed to have had Asperger Syndrome.

Where we are today

In May 2013 the American Psychiatric Association (APA) completed the fifth edition of the Diagnostic and Statistical Manual of Mental Disorders (DSM-5). The DSM is the standard reference for diagnosing mental illness and disabilities in North America, and was last fully revised in 1994. The latest version introduces a new diagnostic category called Autism Spectrum Disorder that replaces the previous diagnoses of Autistic Disorder, Asperger’s Disorder, and PDD-NOS (Pervasive Developmental Disorder Not Otherwise Specified).

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