Autism is difficult to diagnosis. When the diagnosis is made, it can be difficult for parents to accept. Denial is the first response, and it may last for so long that treatment may be delayed.

Parents are usually the first to suspect that something is wrong. A previously normal child will suddenly act oddly. Language development may stop or regress. Social reactions may become inappropriate or disappear. Bizarre behavior may appear, such as emotional breakdowns or obsessive repetition. Such symptoms should be mentioned at routine doctor visits to determine if a specialist needs to be consulted.

Professionals who specialize in autism—child psychiatrists, child psychologists, developmental pediatricians, and pediatric neurologists—will observe the child's behavior, social contacts, and communication skills. They will assess mental and social skills and develop a detailed history of the child's behavior. Some doctors ask parents to bring in videotapes of the child at home. Photo albums and other records may help identify time sequences.

If autism is suspected, other tests may include:

Psychological Tests

A variety of age-appropriate questionnaires and skill tests compare a child's abilities and responses to standards established by testing thousands of children who do not have autism. Some test motor skills, like stacking blocks. Some test visual and coordination skills. Some compare daily activities with others of the same age.

IQ Tests

These are comparative evaluations of individuals at the same age with respect to age-appropriate intellectual skills, like pattern recognition and problem solving. An IQ is the ratio of the child's calendar age to his intellectual age—the average performance of others at a given age. For example, if a 5-year-old child performs like a 10-year old, his IQ would be 200.

Blood and Urine Tests

Thousands of tests evaluate physical health. Some are done routinely, like a blood count and urinalysis. Others types of blood and urine tests are done only rarely for unusual conditions. Your doctor will select tests that are appropriate.

DNA and Chromosome Testing

Genetic disorders are detected by looking at genes. Certain genetic disorders are associated with autism, like tuberous sclerosis and fragile X syndrome .


This test records the brain's activity by measuring electrical currents through the brain. Abnormalities may indicate a seizure disorder , which is commonly associated with autism.

MRI Scan

MRI scans use magnetic waves to make images of the inside of the body. In this case, it is often done to look for abnormal brain growth that may be related to the cause of your child’s autism.

Revision Information