Autism Checklist for First Diagnostic Evaluation

Autism spectrum disorder (ASD) is a developmental disorder characterized by ongoing problems with social communication, social interaction, and restricted, repetitive behaviors, interests, and activities.1,2 While an experienced clinician can reliably identify ASD in children as young as age 2 years, many children do not receive the diagnosis until they are much older, which delays effective treatment.3 Parents may be able to spot signs and symptoms of ASD very early in their child’s life, which can lead to earlier evaluation and treatment. This article describes what you should do to prepare for the initial evaluation if you suspect your child may have ASD, or if you think you might have ASD.

Prevalence of Autism Spectrum Disorder

In the United States, approximately 1 in every 36 children aged 8 years is estimated to have ASD.4 Boys are approximately 4 times as likely to be diagnosed with ASD than girls.4 Because ASD is a lifelong condition, an estimated 2.2% of U.S. adults (approximately 5.4 million people aged 18 years and older) are living with ASD.5

Early Signs of Autism Spectrum Disorder

Autism spectrum disorder can be diagnosed at any age.6 Symptoms of ASD are generally identified when a child is aged 12 to 24 months, though they may appear earlier than 12 months if severe, or later than 24 months if subtle.1 Parents or caregivers may be able to notice early signs of ASD before their child is 1 year old.2 

Typical early symptoms of ASD include1:

  • A delay in language development; 
  • A lack of social interest or unusual social interactions (such as pulling someone by the hand without trying to look at them);
  • Abnormal patterns of play (such as carrying toys around but not actually playing with them);  and 
  • Atypical communication (such as knowing the alphabet but not responding to their own name). 

The 2 types of symptoms of ASD are difficulties with social communication/interactions and restricted, repetitive behavior, interests, or activities.1 

Specific social communication/interactions problems include avoiding eye contact, having difficulty using nonverbal gestures, using stilted or scripted speech, interpreting abstract ideas literally, having trouble recognizing one’s own emotions as well as the emotions of other people, and having difficulty making or keeping friends.2 

A child who shows restricted interests is extremely focused on a specific subject to the exclusion of other subjects and expects others to be just as interested in that subject.2 A child with ASD has inflexible behavior and extreme difficulty dealing with change, particularly changes in routine or participating in new experiences.2 Repetitive behaviors might include movements such as hand flapping, rocking, or spinning, being hypersensitive to stimuli such as loud noises, and arranging toys or other items in a very particular pattern.1,2  

Studies have shown that, with rare exceptions, a child with ASD will experience deterioration in their social and communication behaviors over the first 2 years of life. During the second year of life (aged 12 to 24 months) repetitive behaviors and abnormal play typically become more obvious. A small number of patients with ASD experience these behavioral declines in adolescence. Some people with ASD may not seek an evaluation for ASD until they are an adult, possibly prompted by an ASD diagnosis in a child in their family.1,2 

While parents can informally assess their child for signs and symptoms of ASD, they also can use tools designed for that purpose. While these tools generally are intended to be used by clinicians, they rely at least in part on input from parents, so parents may find it helpful to explore them before their child is evaluated by a specialist.

The Modified Checklist for Autism in Toddlers (M-CHAT-R; available at is a screening tool intended to be used by primary care providers, specialists, or other professionals to determine a child’s risk for ASD.7 It consists of 2 parts: the M-CHAT-R and the M-CHAT-R Follow-up (M-CHAT-R/F). 

The M-CHAT-R consists of 20 yes/no questions about how a child usually behaves. Scoring of the M-CHAT-R is interpreted as follows7:

  • Total score 0 to 2: Low risk. Repeat screen after second birthday for children under 24 months of age. 
  • Total score 3 to 7: Medium risk. A clinician should administer the M-CHAT-R/F to obtain further details about at-risk responses. If the score is still 2 or higher, the child has screened positive.
  • Total score 8 to 20: High risk. The child should receive immediate diagnostic assessment and early intervention evaluation from a clinician.

If a child screens positive on the M-CHAT-R, a clinician should administer the M-CHAT-R/F, which consists of 20 pass/fail questions and detailed instructions for how to interpret the results.7 Because the goal of the M-CHAT-R is to detect as many cases of ASD as possible, it has a high rate of false positives, which means that not every child whose M-CHAT-R results suggest they are at risk for ASD will be diagnosed with the disorder.7 However, children who screen positive on the M-CHAT-R are at risk for other developmental disorders and should be evaluated by an experienced clinician.7

In addition to M-CHAT, several other tools that include input from parents can be used to screen children for development delays that might suggest a diagnosis of ASD3: 

  • Ages and Stages Questionnaires ( is a general developmental screening tool to be completed by a parent or caregiver. It features 19 age-specific questionnaires that address communication, gross motor, fine motor, problem-solving, and individual adaptive skills. 
  • Parents’ Evaluation of Developmental Status ( is a general developmental screening tool. It is a parent-interview form used to screen for developmental or behavioral problems that warrant further evaluation.
  • Communication and Symbolic Behavior Scales ( is a standardized tool to screen for communication and symbolic abilities in children up to age 24 months.
  • Screening Tool for Autism in Toddlers and Young Children ( is an interactive screening tool for children with suspected developmental delays. It features 12 activities that evaluate play, communication, and imitation skills.

Screening tools such as these are used to help identify a child who might have a neurodevelopmental delay such as ASD, but they do not provide conclusive evidence of a delay and they do not establish a diagnosis.3 Parents who thinks their child might have ASD should express their concerns to their child’s pediatrician. The American Academy of Pediatrics recommends that pediatricians conduct general developmental screening of all children at 9, 18, and 30 months of age, and screening specifically for symptoms of ASD at 18 and 24 months.8 If necessary, the pediatrician will refer parents to a specialist who will conduct a thorough evaluation using the appropriate diagnostic criteria.

Autism Spectrum Disorder Diagnostic Criteria

In order to receive a diagnosis of ASD, a child needs to meet the criteria established by the American Psychiatric Association and published in the Diagnostic and Statistical Manual of Mental Disorders, Fifth Edition, Text Revision.1 Those criteria can be summarized as follows1:

A. Persistent deficits in social communication and social interaction as manifested by all of the following:

  1. Deficiencies in social-emotional reciprocity (such as an inability to engage in normal back-and-forth conversation);
  2. Deficiencies in nonverbal gestures used in social interaction (such as problems with eye contact, body language, or understanding or using gestures); and
  3. Deficiencies in developing, maintaining, and understanding relationships (such as a lack of interest in peers).

B. Restricted, repetitive patterns of behavior, interests, or activities, as manifested by at least 2 of the following:

  1. Repetitive motor movements, use of objects, or speech (such as body rocking, arm or hand flapping, lining up toys, repeating words just spoken by another person);
  2. Insistence on sameness, inflexible adherence to routine, or ritualized patterns of behavior (such as difficulty with transitions, rigid thinking patterns, need to eat the same food each day);
  3. Highly restricted, fixated interests that are abnormal in intensity or focus (such as a strong attachment to peculiar objects); and
  4. Hypersensitivity or hyporeactivity to sensory input or abnormal interest in sensory aspects of the environment (such as indifference to pain or temperature, adverse response to specific sounds or textures).

To meet these criteria, a child must not only have the required number of symptoms but the symptoms must have been apparent early in the child’s developmental period and must cause significant impairment in functioning.1 These symptoms must not be better explained by an intellectual disability or global developmental delay.1

Autism Spectrum Disorder Checklist for Parents

To best help a child who they suspect might have ASD, parents can be better informed about the condition and diagnosis. Some checklist items for parents to address include:

  • Keep track of your child’s developmental milestones through the Centers for Disease Control and Prevention (CDC) milestone tracker app (, which outlines incremental milestones for children from age 2 months to 5 years.9
  • Research the initial signs/symptoms and diagnostic criteria of ASD.1
  • Follow the recommendations outlined by the CDC’s “Learn the Signs. Act Early” program (
  • Use a developmental screening tool, such as the M-CHAT-R or Ages and Stages Questionnaire, to prepare for your child’s initial diagnostic evaluation with their pediatrician.3
  • Seek out an evaluation from a specialist such as a psychiatrist or psychologist.2

Autism Spectrum Disorder Checklist for Patients

An adolescent or adult who suspects they may have ASD can follow a similar checklist:

  • Research the symptoms and diagnostic criteria of ASD.
  • Express your concerns to your primary care provider.
  • Seek out a specialized evaluation from a specialist.

Related Articles