How Early Can Autism be Diagnosed?

The American Academy of Pediatrics recommends that all children be screened for autism at their 18- and 24-month well-child visits. If there are any concerns about a child's development, they may be referred for further evaluation.

steven zauderer
Steven Zauderer
December 13, 2023
min read

Early Detection of Autism

Autism spectrum disorder (ASD) is a developmental condition that can be diagnosed in early childhood. Early detection of autism is crucial for several reasons, including the ability to access necessary interventions and support. Understanding how early autism can be diagnosed is essential for parents and caregivers in recognizing the signs and seeking appropriate evaluation.

The Importance of Early Diagnosis

Early diagnosis of autism is of paramount importance as it allows for timely intervention and support. By identifying autism at an early stage, parents and caregivers can gain a better understanding of their child's unique needs and provide appropriate interventions. Early intervention services, such as behavioral therapies and educational support, can be initiated to enhance the child's development and improve long-term outcomes.

Additionally, early diagnosis enables parents to connect with support networks and resources tailored to the specific challenges associated with autism. It empowers parents to advocate for their child's needs and collaborate effectively with healthcare professionals, therapists, and educators.

How Early Can Autism Be Diagnosed?

Autism can be diagnosed as early as 18 months, although the average age of diagnosis tends to be around 4 years old. However, it is important to note that signs of autism can often be observed in infancy. While it may be challenging to make a definitive diagnosis in very young children, certain early red flags can indicate the need for further evaluation.

It is essential for parents to be aware of the early signs of autism in infants and newborns. These signs may include a lack of responsiveness to their name, limited eye contact, delayed or absent babbling, and a lack of interest in social interactions.

If parents or caregivers notice any concerning behaviors or developmental delays, it is recommended to consult with healthcare professionals who specialize in autism diagnosis. These professionals may include pediatricians, developmental pediatricians, or child psychologists. They can conduct a comprehensive evaluation utilizing various assessment tools and tests to determine if a child meets the criteria for an autism diagnosis.

Early detection and diagnosis of autism open doors to early intervention services, parental empowerment, and improved long-term outcomes for individuals on the autism spectrum. By recognizing the importance of early diagnosis and understanding the signs of autism in young children, parents can take proactive steps to ensure their child receives the support and resources they need.

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Understanding Autism Diagnosis Criteria

To accurately diagnose autism, professionals rely on established diagnostic criteria. These criteria provide a standardized framework for identifying and assessing the core features of autism spectrum disorder (ASD). In this section, we will explore the Diagnostic and Statistical Manual of Mental Disorders (DSM-5), the primary diagnostic tool used, as well as the core areas of impairment and additional diagnostic tools.

Diagnostic and Statistical Manual of Mental Disorders (DSM-5)

The Diagnostic and Statistical Manual of Mental Disorders (DSM-5) is the primary resource used by healthcare professionals to diagnose autism. Published by the American Psychiatric Association, the DSM-5 provides a comprehensive set of criteria and guidelines for diagnosing various mental health conditions, including ASD.

The DSM-5 outlines two main criteria that must be met for an autism diagnosis:

  1. Persistent deficits in social communication and social interaction: This criterion focuses on difficulties in social-emotional reciprocity, nonverbal communication skills, and developing and maintaining relationships.
  2. Restricted, repetitive patterns of behavior, interests, or activities: This criterion highlights the presence of repetitive behaviors, restricted interests, and sensory sensitivities.

To receive a diagnosis of autism, an individual must exhibit symptoms from both of these categories, and these symptoms must be present from early childhood, even if they may not become fully apparent until later.

Core Areas of Impairment

To further understand autism diagnosis criteria, it is important to explore the core areas of impairment that are assessed. These areas include:

  1. Social Communication and Interaction: This involves challenges in social-emotional reciprocity, such as difficulties with back-and-forth conversation, sharing emotions, and understanding nonverbal cues like facial expressions and body language.
  2. Restricted and Repetitive Behaviors: This encompasses repetitive movements, insistence on sameness, highly specific interests, and a resistance to change.

Additional Diagnostic Tools

In addition to the DSM-5 criteria, healthcare professionals may use additional diagnostic tools to gather comprehensive information and assess an individual's development and functioning. These tools can include:

  • Developmental and Behavioral Questionnaires: These questionnaires are completed by parents, caregivers, or teachers and provide valuable insights into an individual's behavior, communication, and development. Examples include the Autism Diagnostic Interview-Revised (ADI-R) and the Social Communication Questionnaire (SCQ).
  • Direct Observations: Professionals may directly observe the individual's behavior and interactions in various settings to gather more information and assess the presence of autism symptoms.
  • Clinical Assessments: These assessments may involve cognitive testing, language assessments, and adaptive functioning evaluations to further understand an individual's strengths and challenges.

By using the DSM-5 diagnostic criteria and additional tools, healthcare professionals can provide a comprehensive evaluation and diagnosis of autism. It is important for parents and caregivers to be aware of these criteria and to seek professional guidance if they have concerns about their child's development.

Red Flags for Autism

Recognizing the early signs of autism is crucial for early intervention and support. While each individual with autism is unique, there are common red flags that parents and caregivers can look out for. These red flags primarily fall into three key areas: social communication and interaction, restricted and repetitive behaviors, and sensory sensitivities.

Social Communication and Interaction

Children with autism often exhibit challenges in social communication and interaction. Some red flags to be aware of include:

  • Limited Eye Contact: Difficulty establishing and maintaining eye contact during interactions.
  • Delayed or Absent Language: Late onset of speech or limited use of words or phrases to communicate.
  • Lack of Social Engagement: Avoidance of social interactions, such as not responding to their name or showing little interest in playing or interacting with others.
  • Difficulty with Nonverbal Communication: Challenges in understanding and using gestures, facial expressions, and body language to convey and interpret meaning.

If you notice these red flags, it may be important to consult with a healthcare professional or specialist who can provide a comprehensive evaluation.

Restricted and Repetitive Behaviors

Individuals with autism often engage in repetitive behaviors and have a restricted range of interests. Some red flags in this area include:

  • Repetitive Movements: Repetitive movements such as hand-flapping, rocking, or spinning objects.
  • Obsessive Interests: Intense preoccupation with specific topics or objects, often beyond what is developmentally appropriate.
  • Rigid Routine and Resistance to Change: Strong resistance to changes in routine or difficulty adapting to new situations.
  • Stereotyped Behaviors: Unusual behaviors, such as lining up toys or arranging objects in a precise manner.

These behaviors may vary in intensity and manifestation among individuals with autism. If you observe such red flags, it is advisable to seek a comprehensive evaluation from professionals who specialize in autism diagnosis.

Sensory Sensitivities

Many individuals with autism have heightened sensitivities to sensory input. Some red flags related to sensory sensitivities include:

  • Over- or Under-Sensitivity to Sound: Reacting strongly to certain sounds or exhibiting a lack of response to others.
  • Hyper- or Hypo-Sensitivity to Touch: Reacting strongly to certain textures or exhibiting a lack of response to touch.
  • Unusual Reactions to Lights or Visual Stimuli: Reacting strongly to bright lights or specific visual stimuli.
  • Unusual Smell or Taste Preferences: Displaying aversions or intense preferences for certain smells or tastes.

These sensory sensitivities can significantly impact an individual's daily life and interactions. If you suspect sensory sensitivities in your child, it is advisable to consult with professionals who can provide guidance and support.

By being aware of these red flags for autism, parents and caregivers can take proactive steps towards early detection and intervention, ultimately leading to improved outcomes for individuals with autism.

The Diagnostic Process

When it comes to diagnosing autism, a comprehensive and systematic approach is crucial. The diagnostic process typically involves several steps, including screening and referral, a comprehensive evaluation, and collaboration with professionals.

Screening and Referral

The first step in the diagnostic process is often a screening. Screening tools are designed to identify individuals who may be at risk for autism and require further evaluation. These tools are typically administered in various settings, such as pediatrician's offices, schools, or early intervention programs. The results of the screening can help determine if a referral for a comprehensive evaluation is necessary.

It's important to note that a positive screening result does not provide a definitive diagnosis of autism. Rather, it indicates the need for further assessment to determine if the individual meets the criteria for an autism diagnosis.

Comprehensive Evaluation

A comprehensive evaluation is a thorough assessment conducted by a team of professionals with expertise in diagnosing autism. This evaluation involves gathering information from multiple sources, including parents, caregivers, and teachers, to obtain a comprehensive view of the individual's behavior and development.

The evaluation process typically includes a combination of standardized tests, interviews, and direct observations. These assessments focus on the core areas of impairment outlined in the Diagnostic and Statistical Manual of Mental Disorders (DSM-5), which is the primary diagnostic tool used by clinicians. The DSM-5 provides specific criteria that must be met in order to receive an autism diagnosis.

In addition to the DSM-5 criteria, professionals may also use other diagnostic tools, such as the Autism Diagnostic Observation Schedule (ADOS) or the Childhood Autism Rating Scale (CARS), to gather more detailed information about the individual's behavior and social communication skills. These tools help to ensure a comprehensive evaluation and accurate diagnosis.

Collaborating with Professionals

The diagnostic process involves collaboration between various professionals to ensure a comprehensive evaluation and accurate diagnosis. This collaboration may include pediatricians, psychologists, speech-language pathologists, occupational therapists, and other specialists who have expertise in diagnosing and treating autism.

Working together, these professionals share their findings and observations to develop a comprehensive understanding of the individual's strengths, challenges, and developmental needs. This collaborative approach helps to ensure that the diagnosis is accurate and that appropriate interventions and support services can be recommended.

It's important for parents to actively participate in the diagnostic process and provide valuable insights about their child's behavior and development. By sharing their observations and concerns, parents play a critical role in helping professionals make an accurate diagnosis and develop an appropriate treatment plan.

The diagnostic process for autism can be complex, but by following a systematic approach that includes screening, a comprehensive evaluation, and collaboration with professionals, individuals can receive an accurate diagnosis that paves the way for early intervention and support.

Benefits of Early Diagnosis

Early diagnosis of autism can bring a multitude of benefits for individuals and their families. By identifying autism at an early stage, appropriate interventions and support can be provided, leading to improved outcomes for those with autism. Let's explore some of the key benefits of early diagnosis.

Access to Early Intervention Services

One of the most significant advantages of early diagnosis is the access to early intervention services. These services are specifically designed to address the unique needs of individuals with autism and provide targeted support from an early age. Early intervention programs often incorporate various therapies, such as applied behavior analysis (ABA), speech therapy, occupational therapy, and social skills training.

Research has shown that early intervention can lead to significant improvements in communication skills, social interaction, and adaptive behaviors for individuals with autism. By starting intervention programs at a younger age, children have a greater chance of reaching their full potential and achieving developmental milestones. Early intervention services play a crucial role in helping individuals with autism thrive and succeed throughout their lives.

Parental Empowerment and Support

Early diagnosis of autism empowers parents with knowledge and understanding about their child's unique needs. It provides them with an explanation for their child's behaviors and challenges, helping to alleviate feelings of confusion or guilt. With a diagnosis in hand, parents can access resources, support groups, and educational materials specifically tailored for families of individuals with autism.

By connecting with other parents who are going through similar experiences, parents can gain valuable insights, advice, and emotional support. Parental empowerment and support are vital components of navigating the autism journey, allowing parents to make informed decisions, advocate for their child's needs, and foster a nurturing environment at home.

Improved Long-Term Outcomes

Early diagnosis and intervention significantly contribute to improved long-term outcomes for individuals with autism. The early identification of autism allows for early implementation of strategies to address challenges and promote development. It enables professionals to tailor interventions based on an individual's specific strengths and weaknesses.

Research has indicated that early intervention can lead to better cognitive, social, and communication skills in children with autism. It can positively impact school readiness, academic achievement, and overall quality of life. Early diagnosis and intervention set the stage for individuals with autism to reach their maximum potential and lead fulfilling lives.

By recognizing the importance of early diagnosis, parents and healthcare professionals can work together to identify and support individuals with autism as early as possible. Early access to intervention services, parental empowerment, and improved long-term outcomes are just a few of the many benefits that early diagnosis can bring to individuals and families affected by autism.


What age can autism be diagnosed?

Autism can be diagnosed as early as 18 months of age, although some children may not receive a diagnosis until they are older.

Can parents diagnose autism on their own?

No, only trained professionals can diagnose autism. However, parents and caregivers who have concerns about a child's development should seek evaluation from a healthcare professional.

What should I do if I suspect my child has autism?

If you suspect that your child has autism or if you have concerns about their development, talk to your pediatrician. They can refer you to specialists who can evaluate your child and provide appropriate treatment and support.

Are there any genetic tests for autism?

There is currently no single genetic test that can diagnose autism. However, research suggests that genetics may play a role in the development of autism. In some cases, genetic testing may be recommended as part of the diagnostic process.

Can girls have autism too?

Yes, girls can have autism. While it is more common in boys than girls, research suggests that many girls with autism are underdiagnosed or misdiagnosed due to differences in how they present symptoms compared to boys.

Is there a cure for autism?

There is currently no cure for autism, but early intervention and therapy can significantly improve outcomes for children with ASD. The goal of treatment is to help individuals with ASD develop the skills they need to communicate, socialize, and function independently.


In conclusion, autism can be diagnosed as early as 18 months of age through a comprehensive evaluation by a team of professionals. Early diagnosis and intervention are critical for children with autism and can significantly improve outcomes. If there are any concerns about a child's development, it is important to seek evaluation and early intervention as soon as possible.


steven zauderer

CEO of CrossRiverTherapy - a national ABA therapy company based in the USA.

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