How are Neurodevelopmental Disorders Diagnosed?

There are no medical tests or blood tests to diagnose neurodevelopmental disorders (NDDs). NDDs are diagnosed by healthcare providers observing a child’s behavior and development, and asking parents/guardians about what they see at home or school. Sometimes there are special written or verbal tests that can help decide if a child has a NDD.

Intellectual disability (ID)

Intelligence testing is part of the diagnosis of ID, but other things are considered as well. A person is diagnosed with ID based on a combination of:

  • Tests of intelligence (IQ tests)
  • Measure of how well a person can manage the activities required for daily life based on their age

Typically, people with ID have an IQ of less than 70 based on scores from specialized written or verbal tests. Activities required for daily life can include things like getting dressed, using the bathroom, and feeding oneself. They also include being able to communicate and socialize with others.  The assessment of how well a person can manage the activities required for daily life is based on information from both a healthcare provider and someone who knows the person and their abilities well.

Autism Spectrum Disorders (ASD)

Developmental screening is part of the diagnosis of an ASD. A healthcare provider asks questions to parents/guardians of the child and also plays with the child to see how the child moves, learns, behaves, and speaks. If there are any delays noticed, an appointment with a specialist may be needed.

The specialist can use a combination of tests (called “tools”) to figure out if a child has an ASD. There are several different tools that can be used. The tools are filled out by the specialist based on what they see when they meet/play with the child, and based on how the parents/guardians describe the child’s skills.