No blood test or brain scan can diagnose autism spectrum disorder (ASD). Instead, professionals use questionnaires and observations to pinpoint ASD warning signs. When enough signs appear, an autism diagnosis is apropriate.

Parents play a key role in a child’s ASD diagnosis. Their observations help doctors understand a child’s behavior.

Adults may not have family members or caretakers available for interviews. Instead, they complete self-tests to help their doctors form a complete picture.

Doctors need time to assess ASD symptoms. Often, multiple appointments are required. But the hard work to get an accurate diagnosis is worthwhile.

A diagnosis gives both children and adults access to appropriate treatment. Skills learned in autism therapy could make navigating the world easier.

Diagnosing Autism in Children

Most children diagnosed with ASD are older than 4 years, says Autism Speaks. Missed opportunities are evident. The earlier children access effective treatment, the more likely it is that they’ll do well in standard environments like classrooms.

Plenty of screening instruments exist, says the American Speech-Language-Hearing Association, including tools made for children.

  • Up to 1 year: These questionnaires are used to screen at-risk children.
  • 6 to 18 months: These tools assess behavioral challenges and vulnerabilities.
  • 9 to 24 months: These tests highlight communication development delays.

Typically, parents or caregivers use these screening tests. They answer questions about how the child reacts or performs throughout the day. They highlight episodes of increasing distress. Parents may also use these tools to track a child’s progress (or lack of it) over time.

Doctors and therapists may use the same screening tests as they work with children. Professionals may also use more sophisticated surveys to compare a child’s progress to that of other children the same age.

Additional medical conditions, including hearing loss or vision problems, can complicate an ASD diagnosis. A doctor may refer a child to another professional to rule out other issues that impede diagnostic accuracy.

At the end of a screening process, a child’s doctor has a wealth of data. As the American Academy of Pediatrics explains, all of those factors come together in an autism diagnosis. Your child’s doctor looks over all these things:

  • Your questionnaires
  • Exam notes
  • Medical testing results
  • Your child’s medical history

Only then can the doctor decide about an ASD diagnosis. If one piece is missing, the doctor may wait to get it before pressing forward.

You may see signs of autism in your child. Online questionnaires may confirm your suspicion that something is amiss.

Your hunches and at-home assessments are important, but you can’t make an ASD diagnosis. Only a doctor can do that, such as a child psychologist, developmental pediatrician, pediatric neurologist, or child psychiatrist. The diagnosis comes only after that professional does a lot of digging.

Diagnosing Adults Is Challenging

Early testing should catch most people with ASD. When done properly, people with autism know about it when they’re young. They use therapy to help them learn how to succeed with autism.

But some adults have never gotten the help they need. They may have grown up wondering if they have the condition and what to do about it.

Diagnosing an adult isn’t easy, says Autism Speaks. Challenges include:

  • Missing viewpoints. Parents may be absent or distant in adulthood, and they can’t fill out questionnaires or speak to a person’s habits and routines. Teachers or supervisors may be adequate substitutes in some cases, but not all.
  • Hidden habits. Adults with ASD are adept at concealing issues. They’ve spent their lives correcting or covering these problems. It can be tough to see the underlying issues.
  • Poor checklists. Most diagnostic tools were made for children, not adults. Researchers are working on this issue.

A doctor’s visit often starts the ASD conversation. Adults explain their thought patterns, challenges, and behavior. Doctors make observations. Then, doctors order tests to rule out other conditions, such as hearing loss or Tourette’s syndrome.

To meet diagnostic requirements for ASD, adults must have:

  • Persistent social deficits, including few social interactions.
  • Repeated, restricted behavior patterns, interests, or activities.
  • Problems that started in childhood and persist into adulthood.
  • Issues that limit and impair daily functioning.

Autism emerges in childhood, and by adulthood, you may understand how to navigate the world around you without help or therapy. But many adults with ASD need help, and without it, they may not get the treatment they need.

The National Autistic Society explains that adults may benefit from diagnosis due to:

  • Context. You may finally understand why certain situations or issues bother you.
  • Appropriate care. People with ASD can be misdiagnosed with schizophrenia or another mental health condition. A proper label means suitable therapy.
  • Entitlements. Your teachers and bosses must adjust to your diagnosis and help you succeed. You may also get the services and benefits you deserve.

Some adults aren’t comfortable with an autism diagnosis. They would rather not know they have the condition. That’s understandable. But if you’re not sure, a talk with a doctor could be what you need to live your best life.

What to Do With a Diagnosis

There is no cure for ASD, experts say. You can’t take a pill to make your symptoms go away.

The goal of treatment isn’t curing the condition. Instead, teams use treatment to help you succeed in the world around you, so you’re not held back by the difficulties ASD can cause.

Researchers say autism treatment is used to “prevent worse outcomes.” This sounds technical or even scary, but it’s quite simple. Therapy could help you or your child to:

  • Focus. Staying on task can mean the difference between staying in school and holding down a job or failing at these tasks.
  • Advocate. Enhanced communication skills help you or your child explain that you have autism, and you need accommodations from family, friends, teachers, and employers.
  • Live independently. Therapies like applied behavior analysis (ABA) can focus on very small tasks, such as heading to the bathroom on time or remembering to eat meals.
  • Connect. With enhanced communication skills, it’s possible to understand others and let them understand you.

Adults with autism may want to celebrate diversity. They don’t want to be cured or forced into a standard model labeled “normal.” They want to be accepted as they are.

Therapy and acceptance aren’t always mutually exclusive. A therapist can help you or your child to overcome challenges without erasing your individuality.

If you or your child is diagnosed with autism, find a treatment team. That should be your top goal.

Look for providers that develop individualized plans to meet you where you are and help you go where you want to go. Just as there is no cure for autism, there is no “one way” to treat it. The best teams will personalize your care, so you get the help you need when you need it.

If you struggle with the diagnosis, ask for help about that too. It might be hard to think about helping a child with ASD, for example. You may worry about the child’s future.

Treatment teams help families work through those emotions. You can then focus on the future and the goals you’ve set.