If you think you or a loved one is autistic, you might be wondering how autism is diagnosed, what screening tools are available, and how to access these tests.

Autism is officially called autism spectrum disorder (ASD). People typically receive their diagnosis in childhood.

Autistic people may have difficulty with communication and social situations. Living in a world that’s not well adapted for autistic people can make things difficult.

Autism looks very different person to person. No two people have the same autistic behaviors or support needs, if any are needed at all.

Some autistic people may mask their autistic behaviors, making it more challenging for them to receive a diagnosis.

Some people also have concurrent conditions, like attention deficit hyperactivity disorder (ADHD). That can make it more difficult for doctors to diagnose autism too.

To receive an accurate diagnosis, you’ll need to have a comprehensive evaluation from a team of specialists. These specialists might include:

  • psychologists
  • developmental pediatricians
  • neurologists

The American Academy of Pediatrics (AAP) recommends that all children get screened for developmental delays during their routine well-child visits at 9, 18, and 30 months old.

To track your child’s overall development, you can view these lists of milestones from 2 months to 5 years old from the Centers for Disease Control and Prevention (CDC). You can also download the CDC’s milestone checklist.

The AAP also recommends specifically screening for autism at the 18- and 24-month visits. Autism signs are often present by 18 months old. Getting your child support and services earlier can help them build their skills and help them thrive.

While the AAP and CDC don’t endorse any specific screening tool, your child’s pediatrician might use these tests:

  • Ages and Stages Questionnaires SE-2 (ASQ-SE2) is a questionnaire that parents complete that looks at communication, gross motor skills, fine motor skills, and problem-solving.
  • Communication and Symbolic Behavior Scales (CSBS) is a one-page checklist for parents to complete when their child is between 6 and 24 months old.
  • Parents’ Evaluation of Developmental Status (PEDS) is a 10-question form for parents to answer.
  • Modified Checklist for Autism in Toddlers (M-CHAT) is a widely used 20-question test for parents to fill out that determines a child’s chances of being autistic.

You can learn more and download some of these screening tools at the CDC’s website.

If you’re concerned about your child’s development at any time, talk with your pediatrician. They can screen your child at any appointment.

When a screening tool suggests developmental delays or signs of autism, your child’s pediatrician may refer you to a specialist. This can include a child psychologist or developmental pediatrician.

Because there’s no one official test to diagnose autism, specialists use a range of screening tools, such as the below autism-specific tests.

Some tests involve practitioners observing your child’s behavior. Other tests ask parents to provide a detailed history of their child’s behaviors:

  • Autism Diagnostic Observation Schedule (ADOS-2) is a test with different modules, depending on the child’s age, for clinicians to observe social skills, communication, play, and repetitive behavior.
  • Autism Diagnostic Interview-Revised (ADI-R) is a parent interview that asks about current and past autism-related behaviors.
  • Childhood Autism Rating Scale Second Edition (CARS-2) is a 15-question test that helps clinicians distinguish between autism and other conditions.

Specialists might also test and evaluate your child’s:

  • hearing and vision
  • language
  • motor skills
  • cognition

Again, it takes a thorough evaluation with an array of screening tools, parental insight, and clinician observations to accurately diagnose autism.

Because some health conditions may be associated with autism, various medical tests might be necessary. These tools include:

  • genetic testing, including the chromosomal microarray (CMA) that looks for extra or missing segments of DNA to diagnose chromosomal conditions, and a test for fragile X syndrome
  • lead screening to test for lead exposure
  • other tests, such as an electroencephalogram (EEG) to diagnose seizure disorders or tests for metabolic disorders

According to guidelines from the AAP, it’s also critical to test for co-occurring conditions, which are common with autism.

Autistic kids may have other challenges related to physical, cognitive, and mental health conditions, such as:

In young kids, healthcare professionals typically look for these early social, behavioral, and communication signs of autism:

  • not looking at objects caregivers point to
  • not smiling when caregivers expect them to
  • not responding to their name
  • preferring solo play
  • avoiding physical contact
  • not giving or sharing objects
  • not having appropriate facial expressions
  • not pointing at things they want or waving to others
  • lack of response to parents’ facial expressions
  • having trouble identifying others’ feelings
  • not making eye contact or making very little eye contact
  • not using single words by 16 months or two-word phrases by age 2
  • not cooing or babbling by 12 months old
  • talking or babbling in the same tone and pitch
  • repeating what others say without really understanding the meaning
  • having a good memory for numbers, letters, songs, or other specific topics
  • losing language or social skills they previously had
  • struggling with minor changes or transitions and preferring routines and rituals
  • engaging in repetitive behaviors, such as rocking, flapping their hands, twirling their fingers, or repeating the same phrases or sounds
  • fixating on certain activities
  • not engaging in pretend play
  • having intense sensitivity to certain sounds, scents, textures, and light, or seeking additional sensory input (e.g., bumping into things)
  • difficulty making friends

Remember, autism looks very different person to person. Autistic kids can have different combinations of these signs or show only a few signs.

If your child receives an autism diagnosis, you might feel overwhelmed and have many questions racing through your mind: Will my child be OK? How will we cope? What does this mean for their future? Where do I even start?

Talk with your pediatrician about services that are available to help autistic kids develop and sharpen their communication, social, motor, and academic skills.

The key is to get educated, find support as early as possible, and have compassion not just for your child but also for yourself.

You also might:

  • Find out whether your child is eligible for early intervention services by calling your state’s early intervention program.
  • Learn about the effective treatment options and services for autistic kids.
  • With the help of a healthcare team, zero in on the specific services and supports your child needs, if any. What foundational skills do they need to sharpen? What are their strengths?
  • Learn what triggers both difficult and positive behaviors for your child. What stresses them out? What do they find soothing and enjoyable?
  • Remember that you and your child aren’t alone. Connect with other parents of autistic kids and check out autism organizations. For example, Autism Parenting Magazine provides a list of support groups.