Understanding Autism: How to Test for Autism in Children

Autism Spectrum Disorder (ASD) is a neurodevelopmental condition affecting around 1 in 36 kids. Often simply referred to as Autism, ASD is defined by differences in social communication or interaction, repetitive behaviors, and restricted interests. Spanning far beyond stereotypes, the way ASD symptoms present can vary extensively. Knowing this is a very important part of understanding Autism and how to test for it accurately.

Getting an early diagnosis is highly encouraged when possible. Like with ADHD, early detection can be beneficial because it can help kids understand themselves, help other people in their lives understand them, open the door to valuable services and support options, and may even protect their mental health. So, what should you know?

This article will go over examples of how signs and symptoms of Autism might manifest in kids, the diagnostic criteria for ASD, and the steps required to obtain an Autism diagnosis for a child first. Then, we'll go over possible challenges and important considerations that can help parents and providers avoid overlooking Autism in different populations, as well as a more in-depth overview of why a diagnosis matters.

Signs and Symptoms of Autism in Children

Autistic children may have a wide variety of symptoms, skills, and abilities. This is what the "spectrum" part of Autism Spectrum Disorder refers to. Here are some well-known and lesser-known signs and symptoms of Autism in children. 

Social communication challenges

There are three areas of social communication challenges children with Autism Spectrum Disorder experience, but all of them can manifest in dramatically different ways. These include challenges with or differences in:

• Social-emotional reciprocity. For example, limited social initiation, unusual ways of initiating social contact, not responding when their name is called, not sharing objects, one-sided conversation, or tangential speech.
• Non-verbal communication behavior. For example, not understanding other people's facial expressions, gestures, or body language, poor eye contact, limited or exaggerated facial expressions, or abnormal speech.
• Developing, maintaining, and understanding interpersonal relationships. For example, not knowing to adjust behavior for differing social situations or contexts, trouble understanding other people's perspectives, lack of interest in peers, lack of cooperative play beyond age two, having an interest in friendship and other kids but lacking skills necessary for social interactions and friendships, not wanting to play with other children of their own age or developmental level, or being "in their own world."

To varying degrees, autistic children may unintentionally use inappropriate behaviors in social settings. Some may learn, quite early on, to mask social and communication-related symptoms.

Repetitive behaviors

Repetitive behaviors could be apparent, or they could be difficult to notice. Examples include but aren't limited to:

• Repetitive hand movements (e.g., flicking fingers, flapping hands, clapping, twirling hair around fingers).
• Repetitive body movements (e.g., stepping from one foot to the other, swaying, rocking, pacing).
• Having an intense or obsessive interest in a specific topic (this is called a special interest). This can pair with restricted interests, which means that the child will not have as wide a range of interests as other kids.
• Repeating words, sentences, or phrases (echolalia).
• Repetitive sounds (e.g., humming, grunting). 
• Turning light switches off and on.
• Opening and closing doors.

Many of these, like repetitive hand or body movements, are suspected to be ways of stimming (self-stimulatory behavior), though not all. Some kids show other symptoms, like abnormal or unusually formal speech.

Sensory sensitivities

Children with ASD may experience various atypical reactions to sensory input. Common examples of sensory issues and sensitivities include but aren't limited to:

• Indifference to pain or hot and cold temperatures that would usually lead to a reaction
• Adverse reactions to haircuts, being touched, having their teeth brushed, or having nails cut
• Adverse reactions to certain textures (e.g., food textures, clothing materials, clothing tags)
• Adverse reactions to certain sounds, which may not bother others
• Fascination with lights or movement (e.g., moving water) or other types of sensory input

Autism Spectrum Disorder can come with over or under-reactivity to sensory input or a combination of both. Like with repetitive behaviors and social-communication symptoms, this is not a complete list of all of the ways sensory sensitivities could manifest.

Developmental delays

In early childhood, providers should check for developmental delays. The American Academy of Pediatrics recommends that kids are screened for Autism at well child visits at 18 months old and 20 months old and this is often accomplished through a developmental screener completed by the child’s caregiver. Differences in social communication skills like not cooing or babbling, not responding to their name, speech delay, or not smiling back at parents are some very early symptoms parents and providers might notice. Slight delays in potty training can also be common. Not all autistic children experience delayed developmental milestones, but some do. 

Diagnostic Criteria for Autism Spectrum Disorder

Looking at the examples of Autism symptoms above can help parents understand what might qualify their child for an Autism diagnosis. The diagnostic criteria for Autism can be easy for the untrained eye to misinterpret, especially at first glance. Screening tools help parents and providers detect possible symptoms they may otherwise miss in some cases. As time goes on, we expect that screening tools will start to include more diverse symptom presentations so that professionals and parents can pick up on them more easily. 

DSM-5 criteria

Autism Spectrum Disorder is diagnosed using the most recently updated criteria in the Diagnostic and Statistical Manual of Mental Disorders (DSM). As of 2024, the most recent version of the DSM is the DSM-5-TR, updated in 2022. Right now, the diagnostic criteria for Autism states that individuals must experience the following: 

• Challenges in all three areas of social communication and interaction (social-emotional reciprocity, non-verbal communication behavior, and developing, maintaining, and understanding interpersonal relationships).
• At least 2-4 types of restricted, repetitive behaviors, such as insistence on sameness, inflexible routines, ritualized patterns of behavior or speech, highly restricted and fixed interests, and over or under-reactivity to sensory input.

These symptoms must not be better explained by another condition, though Autism can co-occur with other conditions. They must be present in the child's early developmental period (though they may not manifest fully or interfere with a child's life as much until they age and the demands of life increase), and they must impede important areas of functioning, like social situations, school, or other parts of life. 

Screening tools and assessments

Multiple screening tools and assessments can help detect ASD. The Autism Diagnostic Observation Schedule, Second Edition (ADOS-2) test is largely considered the golden standard for diagnosing Autism in children and adults at this time. Depending on a person's age and communication level, the ADOS-2 involves a semi-structured play session or interview. The Autism Diagnostic Interview, Revised (ADI-R) is also a common standardized test. 

Other tools used to help detect Autism include but aren't limited to:

• Behavior rating scales, like the Childhood Autism Rating Scale (CARS) and the Gilliam Autism Rating Scale (GARS).
• Screening tools, like the Screening Tool for Autism in Toddlers and Young Children (STAT), Modified Checklist for Autism in Toddlers, (M-CHAT), and the Ages and Stages Questionnaire (ASQ).

Speech and language tests, direct observation, genetic testing, parent interviews, mental health testing, hearing and vision screenings, and other tools may also be used as a part of your child's comprehensive Autism assessment. The exact combination of tests your child undergoes for a potential Autism diagnosis might depend on various factors, such as symptom presentation.

Importance of a comprehensive evaluation

An Autism assessment must be thorough to ensure that a child gets an accurate diagnosis. For example, a provider may need to rule out other concerns, which is usually the reason for hearing or vision screenings. Similarly, a formal assessment could help detect possible signs of co-occurring conditions and should look for all possible symptom presentations. 

Steps to Testing for Autism in Children

What happens once a parent notices possible signs of Autism in their child? Every family might have a slightly different trajectory, but it is most often the case that kids and parents move through the following four steps.

Initial screening by pediatrician

Pediatricians can provide an informal screening for ASD symptoms to determine whether or not they will refer the child to a specialist for a formal assessment. They may use a screening questionnaire such as the STAT or M-CHAT. Screenings are shorter and less thorough than an official Autism assessment. Parents can sometimes help by using an at-home questionnaire provided by a qualified health provider and taking the results back to a healthcare provider for further discussion.

Referral to a specialist

Once a pediatrician determines the need for an Autism assessment, they can refer children for a diagnostic evaluation. Commonly, this means getting a referral to a child psychologist, psychiatrist, neurologist, or developmental pediatrician.

Comprehensive assessment by a multidisciplinary team

A multidisciplinary team is a team of multiple providers. Most kids will see multiple providers throughout their diagnostic process. Each provider on your child's diagnostic team may have specialized areas of knowledge. In turn, they can work together to provide a comprehensive, holistic (whole-person) view of your child's symptoms. 

Development of an individualized treatment plan

Once your child has a diagnosis of Autism Spectrum Disorder, they may gain access to certain services. Parents will make the ultimate choice regarding what services a child participates in. There are a number of different treatments and forms of support that can help kids with Autism and related disorders. For example, occupational therapy, social skills training, applied behavior analysis, social interaction therapy, or special education services. Your child's treatment plan may depend on their specific symptoms, challenges, and strengths.

Challenges and Considerations in Testing for Autism

The American Psychiatric Association accurately calls Autism a complex condition. Because of variability in symptoms and presentation, differences in cultural norms, and other factors, it can be more difficult for some families to get their child an appropriate diagnosis. Some providers have a greater understanding of how to diagnose Autism in varying populations than others.

Variability in symptoms and presentation

One of the main complexities in diagnosing or detecting Autism is the wide variety of ways symptom categories can present. Taking social communication and interaction symptoms as an example, one autistic child could be very talkative, but another might be non-verbal. Here are three examples of challenges that may hinder proper diagnosis of ASD:

• Children with lower support needs may be less likely to get detected.
• Girls and women may present differently (e.g., may be high-masking or compensate for symptoms), leading to under-diagnosis in the population.
• Children who are more talkative or who are on the hyper-expressive end (e.g., extreme emotional reactions and facial expressions) may need testing from providers who deeply understand the diverse ways Autism symptoms can present.

Talking with a healthcare provider beforehand can help you determine whether they have experience providing Autism assessments and diagnoses in children with presentations similar to your child.

Cultural and linguistic considerations

All cultures have different norms. Symptoms of Autism, like differences in social or communication skills, can sometimes be interpreted differently depending on the norms within your culture. For example, in some cultures, direct eye contact can be considered disrespectful in specific scenarios. Speech and linguistics can also vary in families. Culturally sensitive interventions, including language and translation services, when applicable, are important in pediatric primary care settings and all other healthcare settings for this reason.

Importance of early intervention

Early intervention matters for more than one reason. First, an Autism diagnosis can open the door to important forms of support like therapy, special education services, and disability benefits. All of these things can be essential for kids and families. However, it's also worthwhile to consider how going without a diagnosis can impact mental health.

With more people getting an accurate diagnosis later in life, researchers have been able to obtain information regarding the potential impacts of growing up autistic without a diagnosis. Some research has found that adolescents with undiagnosed neurodevelopmental disorders, including both Autism and ADHD, have increased rates of anxiety, depression, and other mental health symptoms.

It's also true that co-occurring disorders are common for people with Autism. When neurodevelopmental and related disorders are properly diagnosed, kids can establish strong coping skills and gain an understanding of themselves. Early intervention often means that kids can get individualized care for their unique set of symptoms.

Conclusion

Understanding Autism is important because it can help parents detect possible signs of Autism in their children. Similarly, providers must understand the diverse ways Autism can present so that they can diagnose autistic children appropriately. Other barriers to diagnosis can include but aren't limited to cultural and language differences in families. Culturally sensitive services are integral for this reason. 

Common tests and tools used during a diagnostic evaluation for ASD include but aren't limited to the Autism Diagnostic Observation Schedule (ADOS), Autism Diagnostic Interview, Revised (ADI-R), and various screenings or questionnaires. 

Getting an appropriate diagnosis from a qualified medical or mental health professional in early childhood means that kids can access important services. For example, education accommodations for school age kids and appropriate therapies for a child's needs or age group. 

Here are some additional resources for families seeking additional support and information about Autism:

Learn more about early diagnosis and intervention services on the CDC website.

Get support through groups like Parent-to-Parent or the Joon ADHD Parent Support Group on Facebook.