Autism is a neurological, developmental disorder that causes problems with social interaction, communication, inflexible behaviour and obsessive interests. It was first identified by Kanner in 1943.

Autistics and cousins (ACs) typically dislike change, which can lead to rigid routines and repetitive, stereotyped behaviours, and the obsessive interests can get to a point where they interfere with quality of life. However, ACs are individuals like everyone else, and within the diagnostic criteria, there is a huge range.

Many researchers have the view that autism is a continuum, the Autistic Spectrum ranging from the low-functioning, "classically autistic" (so-called "Kanner's Autism", from the first doctor to identify the disorder), who may be profoundly disabled, to the high functioning Asperger's person, who may be able to function in society independantly, even holding down a job, marrying or have a family. Many ACs apparently "move up" the spectrum as they grow up.

The range of intellectual abilities of ACs is also vast, although their true intelligence may be masked by autistic behaviours. Most are thought to be intellectually challenged, but many have an average or well above average intelligence. People who are at this end of the spectrum, with good verbal abilities, are often referred to as "high-functioning autistic" (HFA).

Contents:

1. Autistic Disorder
2. Asperger Syndrome
3. Childhood Disintegrative Disorder
4. Rett Syndrome
5. Pervasive Developmental Disorder Not Otherwise Specified

See also:

• Issues: Common Topics of Discussionand Debate on a.s.a for a discussion of causes, cures, and theories about autism.
• Resources: General Autism Links
• Internet Mental Health for all the diagnostic criteria linked to from this page (and a lot more).

1. Autistic Disorder

Diagnostic criteria: DSM-IV, ICD-10

The official term for "classic" or "Kanner's" autism is Autistic Disorder. When most people say "autism", this is what they mean.

2. Asperger Syndrome

Diagnostic criteria: DSM-IV, ICD-10

Asperger's Syndrome (AS), first identified by Hans Asperger in 1944, is typically described as "mild" autism, but people with AS may dispute that particular definition, since it seems rather dismissive of their difficulties. Children with AS do not have the language delays typical of other's on the Spectrum, but many researchers believe that AS is a form of HFA, or even that AS and HFA are the same thing. On the a.s.a. newsgroup, we generally refer to AS and HFA as different in terms of degree, and language development.

3. Childhood Disintegrative Disorder

Childhood Disintegrative Disorder (CDD) is a Pervasive Developmental Disorder (PDD) which looks almost exactly like autism. The differences are that in CDD there is a period of normal development for at least 2-3 years before the onset of autistic symptoms. People with CDD are usually on the "low functioning" end of the autistic spectrum and have a poor prognosis for improvement.

4. Rett Syndrome

Rett Syndrome is a complex genetic condition which is found almost exclusively in girls. In some ways the early stages of Rett's can look like autism, but the progression of the condition is different. Girls with Rett Syndrome have normal early development followed by degeneration in motor and communication skills. After a few years, the condition stabilizes and some skills may be regained.

5. Pervasive Developmental Disorder Not Otherwise Specified

"Pervasive developmental disorder not otherwise specified" (PDD-NOS) is a term used more and more commonly, particularly in the USA, to describe individuals who have autistic symptoms, but do not meet the full criteria for autism or AS. Some people say that PDD-NOS is just autism by another name. In UK, they prefer the diagnosis "ASD" to cover such individuals.

By its very nature, PDD-NOS doesn't have any specific diagnostic criteria. The DSM-IV description is as follows:

299.80 Pervasive Developmental Disorder Not Otherwise Specified (Including Atypical Autism)

This category should be used when there is a severe and pervasive impairment in the development of reciprocal social interaction or verbal and nonverbal communication skills, or when stereotyped behavior, interests, and activities are present, but the criteria are not met for a specific Pervasive Developmental Disorder, Schizophrenia, Schizotypal Personality Disorder, or Avoidant Personality Disorder.

For example, this category includes atypical autism -- presentations that do not meet the criteria for Autistic Disorder because of late age of onset, atypical symptomatology, or subthreshold symptomatology, or all of these."

Originally compiled by Anna Hayward on behalf of the alt.support.autism newsgroup, November 2000. Original site design and HTML by Kalen Molton. Please address any general queries to Mike Stanton. Broken links and problems of a technical nature should be addressed to John Muggleton by entering details in the comments box of the form here. Any opinions expressed in this article are personal and should not be construed as medical advice. We are not representatives of any of the companies discussed, nor do we receive any form of commission.

The latest version of this faq is at www.mugsy.org/asa_faq