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DIAGNOSIS & DEFINITIONS

Diagnosis

There is no specific diagnostic test for Autism Spectrum Disorder. The best way to get a diagnosis is via a multi disciplinary assessment. For children, this involves having your child tested by a number of professionals, who will provide you with the information you need to make decisions about program and treatment approaches. For adults, either a psychologist or psychiatrist experienced with Autism Spectrum Disorders can make a diagnosis.

The age of diagnosis these days ranges from approximately 18 months through to adulthood, depending on circumstances. A diagnosis of Autism Spectrum Disorder will only be made if the 'autistic like' pattern of behaviour is apparent before the age of three years. Sometimes a provisional diagnosis is made if the child is very young, and a reassessment at a later date is recommended.

Definitions

The way people think about autism has changed in recent years. It is best described as a group of disorders with a similar pattern of behaviour in three key areas - communication, social interaction and imaginative thought.

The currently favoured term is Autism Spectrum Disorder, with the word 'spectrum' used because no two people with an Autism Spectrum Disorder are exactly alike.

What is an Autism Spectrum Disorder?

As the term suggests, there is no one diagnosis or label. Rather there are several labels that place people at different points on the spectrum. At one end of the spectrum diagnostic labels such as "Asperger Syndrome", "High Functioning Autism" and "PDD-NOS" are used. At the other end of the spectrum you will find labels such as "Autism", "Classic Autism" and "Kanner Autism".

More information

What are the common everyday diagnostic terms or labels?

What are the international classification guides?

There are two international classification guides used to determine the diagnostic criteria for Autism Spectrum Disorders.

DSM IV - Diagnostic and Statistical Manual of Mental Disorders Fourth Edition, 1994, published by the American Psychiatric Association

and/orthe

ICD 10 - International Statistical Classification of Diseases and Related Health Problems Tenth Edition, 1992, published by the World Health Organisation.

Terms Explained

The term Autism Spectrum Disorder is used because there is great variation from person to person depending on the severity and combination of each area of impairment. Autism Spectrum Disorder may also coexist with other conditions or disorders, including intellectual disability, speech and language disorders, anxiety and depression (especially in adolescents and adults), epilepsy, attention disorders, Tourette Syndrome and Down Syndrome. (See also "Why is Autism Spectrum Disorder so hard to understand?")

Autism

In Autism the impairments in the social and communication areas are severe and sustained and clearly present before the age of three years. The child is often anxious, has poor attention and motivation, responds unusually to many different stimuli and is observed as being 'different' from other children. Speech is delayed, or largely absent. A strong reliance on routine is apparent, and the child can have a range of ritualistic behaviours such as toe walking, hand flapping and finger gazing. The child/adult with autism may also be intellectually disabled. Sometimes, clinicians will refer to Classic Autism or Kanner Autism. This is because they believe the child or adult fits the early descriptions of Autism published by Dr Leo Kanner in the 1940's.

High Functioning Autism

High Functioning Autism is a loosely used term (not defined in the diagnostic criteria) to describe a child or adult who meets the criteria for a diagnosis of Autism, but is not as severely affected as the more classically autistic person.

Asperger Syndrome

In Asperger Syndrome there are severe and sustained social impairments, but impairments are not as severe in the language and communication area. Speech usually develops within the normal age range, but the ability to communicate effectively (known as language pragmatics) is impaired. The impairments seem more subtle in the very young child, and become more apparent as the child reaches pre school and school age. The Asperger person is usually in the normal intelligence range.

PDD-NOS

Pervasive Developmental Disorder - Not Otherwise Specified (PDD-NOS) is the diagnosis given for children who present with some of the characteristics of either Autism or Asperger Syndrome, but not severe enough for a diagnosis of either of these conditions. In the ICD 10 and previous editions of the DSM this diagnosis was referred to as Atypical Autism.

Most important of all

Irrespective of the diagnosis or where they fit on the spectrum, each child or adult diagnosed with an Autism Spectrum Disorder is developmentally delayed, has significant difficulties participating in day-to-day life and requires sensitive understanding and specialist support and intervention.