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Understanding Autism Part 2: Evaluation and Diagnosis


This is the second in a three-part series on autism.

Autism Spectrum Disorders (ASDs) are conditions that can affect children’s social skills, language, communication and behaviour. For children with special needs, including ASDs, the earlier they are diagnosed and the earlier intensive treatment is started, the better the outcomes for their development. Studies have shown that children diagnosed with ASD by 3 years of age who receive at least two years of intensive early intervention education and therapy in the preschool years have significantly better outcomes. Diagnosis and intervention by 1 to 2 years of age may lead to even better outcomes.

How do experts diagnose ASD?

ASD is a complex and varied condition. The diagnosis is based on many factors: parents’ and other caregivers’ or teachers’ reports of the child’s behaviour, and comprehensive professional evaluations of the child by a doctor, psychologist or a team of developmental specialists.

Parent-caregiver-teacher observations

You know your child best and have the opportunity to observe him over time, in many different situations. Be alert for the early signs of autism. Some key signs are that your child:
  • Does not babble or make meaningful gestures, such as waving bye-bye or clapping, by 1 year of age

  • Does not respond to his name

  • Does not speak one word by 16 months and does not combine two words by 2 years

  • Loses language or social skills

  • Does not point to things or follow when you point, for example:

    • If you call your child’s name, say, “Look” and point to something or someone across the room, does your child look? At 10 to 12 months of age, typical babies usually respond to their names and look toward the object then look back at you and mimic your facial expression. Children with ASD may not respond to their names and only look where you’re pointing.


    • Does your child point to out-of-reach objects to show you what he wants? At 12 to 14 months of age, most children point to objects they want. Children with ASD rarely point but instead may lead you by the hand to the object.


    • Does your child point to or bring interesting things to show you? By 14 to16 months, most children take pleasure in showing things to their parents. Children with ASD rarely do.


It can also be helpful to review baby albums, family photos and videotapes to remember your child’s behaviours at different ages. If you observe any of the above signs, or any other signs of concern, be sure to talk with your child’s doctor and request a complete developmental screening as soon as possible.

Developmental screening by the doctor

In a complete developmental screening, the doctor will ask you about your child’s skills and behaviours, observe your child’s behaviour, talk with him and examine his language, social skills and motor skills. In addition, the doctor can complete a specific screening checklist for autism. If the developmental and autism screening tests indicate a concern, your child needs to be referred to a developmental specialist (a developmental pediatrician, child psychiatrist or psychologist, or a team of specialists) for a comprehensive diagnostic evaluation. The diagnosis of autism cannot be made until this is completed.

Comprehensive diagnostic evaluation

The purpose of the comprehensive evaluation is to determine whether your child has ASD and which specific condition, and whether your child has any other medical or developmental condition that can involve similar symptoms. The comprehensive evaluation can be done by a developmental specialist or a team, including a developmental pediatrician, child neurologist, child psychiatrist, psychologist, speech therapist, physical or occupational therapist, early childhood educator and social worker. In the United States all children are entitled to a free comprehensive developmental evaluation through the regional centre for developmental disabilities services and/or the public school district. The evaluation can also be done by private developmental specialists through hospitals or clinics. It typically includes:
  • Detailed history from the parents

  • Complete physical exam of the child

  • Observation of your child’s behaviour, play and interactions

  • Developmental assessment of all your child’s skills

  • Standardized autism-specific assessment

  • Hearing test by a pediatric audiologist

  • Language evaluation by a speech therapist

  • Sensory-motor evaluation by a physical or occupational therapist

  • Blood test for lead

  • Neurologic evaluation by a pediatric neurologist. Sometimes other tests may be ordered such as an EEG, CT, MRI and blood tests.

  • Genetic evaluation by a geneticist. This is especially important if your child has unusual physical features, overall developmental delays or if there is a family history of genetic conditions or mental retardation of unknown cause.
After the evaluation has been completed, the team will meet with you to explain the results, including your child’s diagnosis, developmental strengths and weaknesses, treatment recommendations and possible outcomes for your child’s development.

You may have a variety of reactions to the diagnosis of ASD: shock, disbelief, sadness, fear, anger or even relief. This can make it difficult to hear all the information and ask the questions you may have. At the initial meeting, try to get as clear an explanation as possible, some information in writing and contact information for the professionals you can call to follow-up with more questions. It can also be helpful to ask for contacts for a parent support group or other parents of children with the same condition who are willing to provide guidance and support.

Remember, autism is treatable. Intensive treatment and education can help your child develop and progress and also provide you guidance and support to help your child.

For more information, see the first in this series of articles, “Understanding Autism: Recognizing the Possible Symptoms” and part three, “Treatment Options.” Also, visit www.autism-society.org and www.cureautismnow.org.