About autism 
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Close Menu 1.0 Introduction
Open Menu 2.0 History
Open Menu 3.0 The Triad of Impairments
Open Menu 4.0 Possible causes
Open Menu 5.0 Diagnosis
    5.1 How is Autism Diagnosed?
    5.2 International Classification of Diseases (ICD-10)
    5.3 The process of assessment
    5.4 The age of diagnosis
    5.5 The consequences of diagnosis
Open Menu 6.0 Rainman - Fact or Fiction?
Open Menu 7.0 Related Conditions

5.0 Diagnosis

5.1 How is Autism Diagnosed?

There are no medical tests for diagnosing autism or for identifying the sub-groups within the spectrum. An accurate diagnosis must be based on observations of the child's communication, behavior and developmental levels. However, because many of the behaviors associated with autism are shared by other disorders, a doctor may complete various medical tests to rule out other possible causes. The age at which symptoms are identified is important in the diagnosis. The World Health Organization's system for classifying medical disorders (IDC-10) requires that all three of the triad of impairments are present at 36 months of age. The American Psychiatric Association's system (the latest, 1994, version is called DSM-IV) also requires that the age of onset should be recorded

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5.2 International Classification of Diseases


At least 8 of the 16 specified items must be fulfilled.

a. Qualitative impairments in reciprocal social interaction, as manifested by at least three of the following five:

  1. failure adequately to use eye-to-eye gaze, facial expression, body posture and gesture to regulate social interaction.
  2. failure to develop peer relationships.
  3. rarely seeking and using other people for comfort and affection at times of stress or distress and/or offering comfort and affection to others when they are showing distress or unhappiness.
  4. lack of shared enjoyment in terms of vicarious pleasure in other peoples' happiness and/or spontaneous seeking to share their own enjoyment through joint involvement with others.
  5. lack of socio-emotional reciprocity.

b. Qualitative impairments in communication:

  1. lack of social usage of whatever language skills are present.
  2. impairment in make-believe and social imitative play.
  3. poor synchrony and lack of reciprocity in conversational interchange.
  4. poor flexibility in language expression and a relative lack of creativity and fantasy in thought processes.
  5. lack of emotional response to other peoples' verbal and non-verbal overtures.
  6. impaired use of variations in cadence or emphasis to reflect communicative modulation.
  7. lack of accompanying gesture to provide emphasis or aid meaning in spoken communication.

c. Restricted, repetitive and stereotyped patterns of behavior, interests and activities, as manifested by at least two of the following six:

  1. encompassing preoccupation with stereotyped and restricted patterns of interest.
  2. specific attachments to unusual objects.
  3. apparently compulsive adherence to specific, non-functional routines or rituals.
  4. stereotyped and repetitive motor mannerisms.
  5. preoccupations with part-objects or non-functional elements of play material.
  6. distress over changes in small, non-functional details of the environment.

d. Developmental abnormalities must have been present in the first three years for the diagnosis to be made.

The most recent DSM-IV diagnostic criteria (1994) until now are:


Important: This is provided for information purposes only. An accurate diagnosis is the important first step in addressing any needs; such a diagnosis can only be performed by a qualified professional who's familiar with the individual's history.

A. A total of six (or more) items from (1), (2), and (3), with at least two from (1), and one each from (2) and (3).

1. Qualitative impairment in social interaction, as manifested by at least two of the following:

  1. marked impairment in the use of multiple nonverbal behaviours such as eye-to-eye gaze, facial expression, body postures, and gestures, to regulate social interaction.
  2. failure to develop peer relationships appropriate to developmental level.
  3. a lack of spontaneous seeking to share enjoyment, interests or achievements with other people e.g.: by a lack of showing, bringing or pointing out objects of interest.
  4. lack of social or emotional reciprocity.

2. Qualitative impairments in communication as manifested by at least one of the following:

  1. delay in, or total lack of, the development of spoken language not accompanied by an attempt to compensate through alternative modes of communication such as gesture or mime.
  2. in individuals with adequate speech, marked impairment in the ability to initiate or sustain a conversation with others.
  3. lack of varied, spontaneous, make-believe play or social imitative play appropriate to developmental level.

3. Restricted, repetitive and stereotyped patterns of behavior, interests and activities, as manifested by at least one of the following:

  1. encompassing preoccupation with one or more stereotyped and restricted patterns of interest that is abnormal either in intensity or focus.
  2. apparently inflexible adherence to specific nonfunctional routines or rituals.
  3. stereotyped and repetitive motor mannerisms e.g.: hand or finger flapping or twisting, or complex whole-body movements.
  4. persistent preoccupation with parts of objects.

B. Delays or abnormal functioning in at least one of the following areas, with onset prior to age 3 years:

  1. social interaction.
  2. language as used in social communication.
  3. symbolic or imaginative play.

C. The disturbance is not better accounted for by Rett's Disorder or Childhood Disintegrative Disorder.

Diagnosis is difficult for a practitioner with limited training or exposure to autism, since the characteristics of the disorder vary so much. Locating a medical specialist or a diagnostician who has experience with autism is most important. Ideally a child should be evaluated by a multidisciplinary team which may include a neurologist, psychologist, developmental pediatrician, speech/language therapist, learning consultant or other professionals knowledgeable about autism.

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5.3 The process of assessment

The basic principles of assessment involve the following two procedures:

  • An assessment in a clinic which will involve various specialist investigations into intelligence, language, medical and neurological examinations; and
  • More often than not a second assessment will take place by observing the person with autism at home, school or nursery, during play and other situations where social interaction and communication would be seen.

This procedure is likely to take some time as careful assessment will help to identify whether the individual has another similar condition such as Rett's syndrome (in which girls show neurological problems such as hand-wringing and other odd hand movements) or Landau-Kleffner syndrome (a condition characterised by a period of normal language development followed by a fluctuating loss of speech and accompanied by epilepsy).

Not only is it important to distinguish autism from other conditions but also an accurate diagnosis can provide the basis for building an appropriate and effective educational and treatment program.

There are still some grey areas in diagnosing autism, so that terms such as 'atypical autism' (where perhaps some of the classic features did not appear until after the age of 3) and 'autistic features' (where some, but not all, of the features are present) may be used.

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5.4 The age of diagnosis

Many people at the more able end of the autistic spectrum can go through their lives without a diagnosis. Most people would argue that an early diagnosis is most beneficial and allows for appropriate action to be taken.

It may not always be possible to diagnose a person with autism before the age of two, the child may have associated learning difficulties and, as speech and language development is naturally variable, using this as a diagnostic tool may not work.

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5.5 The consequences of diagnosis

Any parent faced with such a diagnosis regarding their child will be confused and feel apprehensive. This is why hundreds of self-help groups exist all over the World.

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