there is concern on the part of the doctor or parents. This is especially true whenever a child fails to meet any of
the following language milestones:
• Babbling by 12 months
• Gesturing (pointing, waving bye-bye) by 12 months
• Single words by 16 months
• Two-word spontaneous phrases by 24 months (not echolalia)
• Loss of any language or social skills at any age
Children not achieving developmental milestones may be referred for an evaluation and a screening for autism.
There are a number of tests and observational checklists available to evaluate children with autism. A certified
professional experienced in the diagnosis and treatment of autism is usually required for the definite diagnosis.
Because there is no biological test for autism, the diagnosis will often be based on very specific criteria from the
Diagnostic and Statistical Manual IV.
An evaluation of autism will often include a complete physical and nervous system (neurologic) examination. It may
also include a specific screening tool, such as:
• Autism Diagnostic Interview - Revised (ADI-R)
• Pre-Linguistic Autism Diagnostic Observation Schedule (PL-ADOS)
• Childhood Autism rating Scale (CARS)
In the diagnosis of children with identified or suspected autism they will often have genetic testing (looking for
chromosome abnormalities) and perhaps metabolic testing. Autism consists of a broad spectrum of symptoms.
Therefore, a single, brief evaluation cannot predict a child's true abilities. Usually a team of different specialists will
evaluate the child for autism.
They may evaluate:
• Language / Communication
• Motor skills
• Success at school
• Cognitive abilities
Sometimes parents are hesitant to have their child diagnosed because of concerns about labeling the child autistic.
However, failure to get an autism diagnosis may delay getting the treatment and services the child needs.
Childhood Autism Rating Scale (CARS)
The childhood autism rating scale (CARS) is a test a behavior rating scale designed to help make a distinction
between children with autism from those with other developmental delays.
CARS is a diagnostic assessment method that rates children with autism on a scale from one to four for various
criteria, ranging from normal to severe, and provides a combined score ranging from no autism to mild autism,
moderate autism, or severe autism.
The autism rating scale is used to observe and individually rate the following fifteen factors.
• Relationships with people
• Emotional response
• Body use
• Object use
• Adjustment to change
• Visual response
• Listening response
• Taste-smell-touch response and use
• Fear and nervousness
• Verbal communication
• Non-verbal communication
• Activity level
• Level and consistency of intellectual response
• Overall impression
When diagnosing autism spectrum disorders it is very important that professionals using the CARS have experience
in assessing children with autism and undergo adequate training in administering and interpreting the CARS.
Diagnosis with the Autism Behavior Checklist
The Autism Behavior Checklist (ABC) is a list of questions about a child's behaviors and is designed to be
completed independently by a parent or a teacher familiar with the child. The ABC test is a general measure of
autism. It is not as reliable as the autism rating scale the content of the test items appears more appropriate for
children over three years old the ABC to be of limited usefulness in identifying young children with autism,
especially when compared with other autism assessment instruments.
Checklist for Autism in Toddlers
The Checklist for Autism in Toddlers (CHAT) is a screening tool designed to identify autistic features to provide
treatment as early as eighteen months. The most effective treatment currently available for autism is the early
intervention program, beginning as soon as possible after a child's diagnosis. Unfortunately, intervention rarely
begins before the age of three years because few children with autism are diagnosed before they reach preschool
CHAT offers physicians a means of diagnosing autism in infancy so that educational programs can be started
months or even years before most symptoms become obvious. CHAT should not be used as a diagnostic
instrument, but it can alert the primary physician that the child needs a referral for an evaluation.
The Autism Diagnostic Interview Revised
The Autism Diagnostic Interview-Revised (ADI-R) is a semi-structured, investigator-based interview for parents
and caregivers of children with a possible autism diagnosis. The interview is based on all the domains of autism as
specified in the DSM-IV criteria. The assessment is focused on children in the 3-5 year range and can be used with
children as young as age two.
The ADI-R is considered by some professionals in the autism field as a measure of high diagnostic accuracy. It
takes several hours to administer and score. The diagnostic interview is conducted at the child’s home or in a
clinic. The assessment begins with a home visit by a therapist who interviews the child's caregivers. A home visit
provides a chance to meet the child and to get a sense of the parents' concerns. This interview may also be
scheduled as a clinic evaluation.
Prelinguistic Autism Diagnostic Observation Schedule
The prelinguistic autism diagnostic observation schedule is an observation scale for diagnosing young children
(under the age of six years) who are not yet using phrase speech and who are suspected of having autism. It is a
semi-structured assessment of play, interaction, and social communication. The scale is administered to the child
with the help of a caregiver. This instrument provides an opportunity to observe specific aspects of the child's
social behavior, such as joint attention, imitation, and sharing of affect with the examiner and parent.
Although educators, parents, and other health care professionals identify signs and symptoms characteristic of
autism, a clinician experienced in the diagnosis and treatment of autism is necessary for accurate and appropriate
diagnosis. Pediatricians, as well as neurologists, speech-language pathologists (SLPs), occupational therapists,
physical therapists, and developmental specialists, among others, may help diagnose autism.