Diagnosing autism spectrum disorder (ASD) can be difficult because there is no medical test, like a blood test, to diagnose the disorder. Doctors look at the child’s developmental history and behavior to make a diagnosis.
ASD can sometimes be detected at 18 months or younger. By age 2, a diagnosis by an experienced professional can be considered very reliable . However, many children do not receive a final diagnosis until much older. Some people are not diagnosed until they are adolescents or adults. This delay means that children with ASD might not get the early help they need.
Early signs of ASD can include, but are not limited to
- Avoiding eye contact,
- Having little interest in other children or caretakers,
- Limited display of language (for example, having fewer words than peers or difficulty with use of words for communication), or
- Getting upset by minor changes in routine.
CDC’s “Learn the Signs. Act Early.” program provides free resources to help families monitor developmental milestones and recognize signs of developmental concerns, including ASD.
As children with ASD become adolescents and young adults, they might have difficulties developing and maintaining friendships, communicating with peers and adults, or understanding what behaviors are expected in school or on the job. They may also come to the attention of healthcare providers because they have co-occurring conditions such as attention-deficit/hyperactivity disorder, obsessive compulsive disorder, anxiety or depression, or conduct disorder.
Monitoring, screening, evaluating, and diagnosing children with ASD as early as possible is important to make sure children receive the services and supports they need to reach their full potential . There are several steps in this process.
Comprehensive Developmental Evaluation
A brief test using a screening tool does not provide a diagnosis, but it indicates if a child is on the right development track or if a specialist should take a closer look. If the screening tool identifies an area of concern, a formal developmental evaluation may be needed. This formal evaluation is a more in-depth look at a child’s development, usually done by a trained specialist, such as a developmental pediatrician, child psychologist, speech-language pathologist, occupational therapist, or other specialist. The specialist may observe the child, give the child a structured test, ask the parents or caregivers questions, or ask them to fill out questionnaires. The results of this formal evaluation determines whether a child needs special treatments or early intervention services or both.