There are no medical tests for diagnosing autism. An accurate diagnosis must be based on observation of the individual's communication, behavior, and developmental levels. However, because many of the behaviors associated with autism are shared by other disorders, various medical tests may be ordered to rule out or identify other possible causes of the symptoms being exhibited. At first glance, some persons with autism may appear to have mental retardation, a behavior disorder, problems with hearing, or even odd and eccentric behavior. To complicate matters further, these conditions can co-occur with autism. However, it is important to distinguish autism from other conditions, since an accurate diagnosis and early identification can provide the basis for building an appropriate and effective educational and treatment program.

A brief observation in a single setting cannot present a true picture of an individual's abilities and behaviors. Parental (and other caregivers' and/or teachers) input and developmental history are very important components of making an accurate diagnosis.

Why Early Identification is Critical

Research indicates that early diagnosis is associated with dramatically better outcomes for individuals with autism. The earlier a child is diagnosed, the earlier the child can begin benefiting from one of the many specialized intervention approaches treatment and education.

The American Academy of Pediatrics recommends that all children be screened for autism by their family pediatrician twice by the age of 2, at 18 months and again at 24 months. The AAP also recommends that treatment be started when an autism diagnosis is suspected rather than waiting for a formal diagnosis. Go to to see the complete list of recommendations. The advantages of early intervention cannot be overemphasized. Children who receive intensive therapy can make tremendous strides in their overall functioning and go on to lead productive lives. Click here for more information on early intervention.

Screening and Screening Instruments

While there is no one behavioral or communications test that can detect autism, several screening instruments have been developed that are now being used in diagnosing autism:

  1. CARS rating system (Childhood Autism Rating Scale), developed by Eric Schopler in the early 1970s, is based on observed behavior. Using a 15-point scale, professionals evaluate a child's relationship to people, body use, adaptation to change, listening response, and verbal communication.
  2. The Checklist for Autism in Toddlers (CHAT) is used to screen for autism at 18 months of age. It was developed by Simon Baron-Cohen in the early 1990s to see if autism could be detected in children as young as 18 months. The screening tool uses a short questionnaire with two sections: one prepared by the parents; the other by the child's family doctor or pediatrician.
  3. The Autism Screening Questionnaire is a 40-item screening scale that has been used with children age four and older to help evaluate communication skills and social functioning.
  4. The Screening Test for Autism in Two-Year Olds is being developed by Wendy Stone at Vanderbilt and uses direct observations to study behavioral features in children under two. She has identified three skill areas that seem to indicate autism: play, motor imitation, and joint attention.

Who Makes a Diagnosis/ Diagnostic Tools

Whether you or your child's pediatrician is the first to suspect autism, your child will need to be referred to someone who specializes in diagnosing autism spectrum disorders. This may be a developmental pediatrician, a psychiatrist or psychologist, and other professionals that are better able to observe and test your child in specific areas.

This multidisciplinary assessment team may include some or all of the following professionals (they may also be involved in treatment programs):

  • Developmental pediatrician - Treats health problems of children with developmental delays or handicaps.
  • Child psychiatrist - A medical doctor who may be involved in the initial diagnosis. He/she can also prescribe medication and provide help in behavior, emotional adjustment and social relationships.
  • Clinical psychologist - Specializes in understanding the nature and impact of developmental disabilities, including autism spectrum disorders. May perform psychological and assessment tests, as well as help with behavior modification and social skills training.
  • Occupational therapist - Focuses on practical, self-help skills that will aid in daily living, such as dressing and eating. May also work on sensory integration, coordination of movement, and fine motor skills.
  • Physical therapist - Helps to improve the use of bones, muscles, joints, and nerves to develop muscle strength, coordination and motor skills.
  • Speech/language therapist - Involved in the improvement of communication skills, including speech and language.
  • Social worker - May provide counseling services or act as case manager helping to arrange services and treatments.

Working With Professionals

It is important that parents and professionals work together for the child's benefit. While professionals will use their experience and training to make recommendations about your child's treatment options, you have unique knowledge about his/her needs and abilities that should be taken into account for a more individualized course of action.

Once a treatment program is in place, communication between parents and professionals is essential in monitoring the child's progress. Here are some guidelines for working with professionals:

  • Be informed. Learn as much as you can about your child's disability so you can be an active participant in determining care. If you don't understand terms used by professionals, ask for clarification.
  • Be prepared. Be prepared for meetings with doctors, therapists, and school personnel. Write down your questions and concerns, and then note the answers.
  • Be organized. Many parents find it useful to keep a notebook detailing their child's diagnosis and treatment, as well as meetings with professionals.
  • Communicate. It's important to ensure open communication - both good and bad. If you don't agree with a professional's recommendation, speak up and say specifically why you don't.

Getting Past the Diagnosis


Often, the time immediately after the diagnosis is a difficult one for families, filled with confusion, anger and despair. These are normal feelings. But there is life after a diagnosis of autism. Life can be rewarding for a child with autism and all the people who have the privilege of knowing the child. While it isn't always easy, you can learn to help your child find the world an interesting and loving place.

Understanding Autism for Dummies (Wiley Publishing, Inc., 2006) by Dr. Stephen M. Shore and Linda G. Rastelli, MA, outlines the following 10 steps families should take after a diagnosis.

1. Learn and read as much as possible. Although the glut of available information may seem overwhelming, the more you read and discover, the easier it will be to understand new information. However, always consider the source of any information you find. And do not focus exclusively on one intervention or therapy; no one treatment works for everyone. You need to find the right combination for your child.

2. Network with other families. Families in similar situations often provide the most important support system of all. Get active in the autism community by attending support group meetings and conferences to meet other parents who are going through the same struggles and are happy to share their experiences. Visit ASA’s online database, Autism Source, for listings of parent support groups and other organizations.

3, Test, Test, Test. Test your child early to get a baseline picture of where he or she is. A clear picture of your child’s biological condition provides a roadmap for treatment and therapies to follow. If you can’t afford all of the tests you need up front, prioritize them with your medical providers’ help.

4. Investigate sources of financial aid. Autism can quickly exhaust your resources, but, fortunately, funding and assistance do exist. Financial aid is generally available at the county level for children under the age of 3 (you’ll need to apply for the Medicaid waiver). Also, keep good financial records, and avoid using the words “autism” or “PDD-NOS” with insurance companies, especially HMOs, as many exclude autism in their policies. If there is a biological abnormality that’s being treated, have the doctor code it as such. 

5. Consider major lifestyle changes. As autism treatment can seriously affect your financial resources, you may have to make major changes (such as changing your job or downsizing your home) or short-term sacrifices to allow for the funds you need to treat your child. Also, if you have a spouse or significant other, you need to establish a division of labor and responsibilities regarding the care of your child. Autism treatment takes sacrifice, but the hard work pays off. Many parents will tell you that the emotional rewards are much more lasting than any hobby or house can bring.

6. Set up an educational/behavioral program in your home. If you can afford it, a structured one-on-one program focusing on education and behavior works for many children with autism. Make sure the program is reputable and that it shares your expectations and goals. You and your tutor/consultant should both sign a contract stating who is responsible for what.

7. Begin therapies. You may be referred to other specialists for therapy, including speech, occupational and physical therapy. These therapies will help your child gain communication, social and physical skills. Insurance providers, including Medicaid, often cover the cost.

8. Address diet and nutrition. Since dietary sensitivities affect many people with autism, consider trying special diets (such as wheat-free/dairy-free) for your child. Based on medical testing and your doctor’s recommendations, you should also start your child on vitamin/mineral supplements geared to his/her needs. Be sure to consult with a nutritionist and pediatrician with expertise in autism.

9. Don’t give up. Attitude is everything! Try to be a morale booster for your family and your team of professionals. Educate doctors who are unfamiliar with autism and provide up-to-date information for those who can help. Be patient as many treatments and interventions take time to produce results. Most importantly, remember to laugh and have fun together as a family.

10. Get out and relax. Make time for yourself. You must take care of yourself to be of any good to your child. Encourage your spouse/significant other to take time to recharge as well.

Last updated: 31 January 2008