Diagnosing Autism

The clinician who conducts the test will ask you for all of your child’s medical records. This includes:

  • any diagnostic and developmental assessments made through community resources
  • screening results
  • genetic testing
  • history of seizures, head trauma, etc.
  • information about your child’s intervention history (i.e., early intervention, occupational therapy, speech therapy, physical therapy)
  • questions and concerns for the doctor

How to Request and Prepare for a Diagnostic Evaluation

If you’ve noticed some early signs of autism in your child, don’t wait. Speak to your child’s pediatrician as soon as possible. Your doctor will likely recommend a diagnostic test.

Your child’s testing should be done by someone who has experience working clinically with children with ASD. They should be trained and certified to conduct any measurements. Finally, if the person doing your child’s assessment is not a Ph.D or M.D., they should be supervised by someone who is.

If you have any questions or concerns about who is conducting your child’s assessment, or if you feel that the assessment is not representative of how your child normally behaves, be sure to ask your physician questions and notify them of any concerns.

Understanding the Tests Used to Diagnose Autism

There are several possible diagnostic assessments your doctor might utilize in addition to the MCHAT.  All are designed to include a clinician’s assessment of your child’s behavior as well as record your own concerns and observations about your child.  Some of the more popular screening tools are:

  1. Autism Diagnostic Interview (ADI) – a 45-minute comprehensive parent interview that asks about possible ASD symptoms in your child (adapted from Lord et al., 1994)
  2. Autism Diagnostic Observation Schedule (ADOS) – a 45-minute observational measure that looks for ASD symptoms (Lord et al., 1999, 2000)
  3. Bayley or the Mullen Scales of Early Learning (MSEL, Mullen) – 60-minute standardized assessments evaluating cognitive, language, motor and other developmental areas. (Mullen, 1997),
  4. Vineland Adaptive Behavior Scales (VABS) – a 45-minute parent interview that provides a measure of adaptive functioning (ability to be independent and solve problems based on the child’s age), assessing communication, daily living, socialization, motor, and problem behaviors (Sparrow et al., 2005)

These tests are intended to provide a clinician with enough information to give a best estimate diagnosis based on DSM-5 criteria for autism.

These evaluations should be covered by your insurance carrier.  Most states mandate that screening and evaluations be paid for by insurance, however, exceptions to these rules exist.  The clinic where your child is being seen will help you identify challenges to getting these evaluations paid for.

Other evaluations and tests

Scientists are discovering new biological features of ASD in infancy even before behaviors emerge in toddlerhood  These include change in the shape of the brain and structures in the brain, biological measures of attention to different parts of a social scene, as well as brain activity. 

Your clinician may recommend an MRI (magnetic resonance image) to check for any abnormalities in the brain.  This is a non-invasive test that takes a picture of the brain.

They may also recommend that your child have an EEG (electroencephalogram).  This is another non-invasive procedure where a cap is put on your child’s head and brainwaves are measured.  This test can also detect seizures in children.

Finally, your doctor may suggest a genetic test to identify potential rare variants that would be causing autism or developmental delays in children.  If a rare genetic disorder is found, there are specialized Patient Advocacy Groups and focused interventions (including gene therapies) that may be available.