Autism or ADHD? How to differentiate between the two

Children with autism spectrum disorder (ASD) or attention deficit hyperactivity disorder (ADHD) often show overlapping symptoms. One common characteristic of someone with ADHD that can also happen with ASD is having trouble staying focused on a task. It can be challenging to get them to finish their homework or their chores. Another common trait of both ASD and ADHD is difficulty with social skills and communication challenges. They might find it difficult to make or maintain friendships and might have a hard time expressing themselves to others. It can be hard for them to maintain a daily schedule or complete self-care tasks like brushing their teeth or bathing daily.

READ MORE: How to Maintain Good Oral Health for Kids with Autism

These are just some of the ways that ADHD and autism can look alike. However, it’s important to know that ADHD and autism are two separate and distinct conditions. The traits of both ASD and ADHD can sometimes look similar, but they are two very different diagnoses.

Autism spectrum disorder specifically impacts a person’s social and communication skills, and includes the presence of specific restricted, repetitive or stereotyped behaviors. Attention deficit hyperactivity disorder, or ADHD, on the other hand, is more related to a person’s ability to attend or pay attention to specific things as well as their ability to regulate their behaviors particularly as it relates to being hyperactive or impulsive.

Comparing ASD & ADHD

To clarify the core of what both ADHD and ASD are as clinical disorders, we’ll briefly review the DSM-5 criteria for each diagnosis. The DSM-5 (Diagnostic and Statistical Manual for Mental Disorders, 5th edition) is a manual that includes all the mental disorders that are currently recognized by mental and behavioral health professionals. It helps provide consistency in assessing and treating the disorders.

Although there is a bit more complexity to diagnosing than simply reading a list of criteria, the criteria listed in the DSM-5 provide a foundation for understanding mental and behavioral health disorders.

Diagnostic Criteria for Autism Spectrum Disorder (ASD)

To meet diagnostic criteria for ASD according to DSM-5, a child must have persistent deficits in each of three areas of social communication and interaction (see A.1. through A.3. below) plus at least two of four types of restricted, repetitive behaviors (see B.1. through B.4. below).

[A] Persistent deficits in social communication and social interaction across multiple contexts, as manifested by the following, currently or by history (examples are illustrative, not exhaustive; see text):

  1. Deficits in social-emotional reciprocity, ranging, for example, from abnormal social approach and failure of normal back-and-forth conversation; to reduced sharing of interests, emotions, or affect; to failure to initiate or respond to social interactions.
  2. Deficits in nonverbal communicative behaviors used for social interaction, ranging, for example, from poorly integrated verbal and nonverbal communication; to abnormalities in eye contact and body language or deficits in understanding and use of gestures; to a total lack of facial expressions and nonverbal communication.
  3. Deficits in developing, maintaining, and understanding relationships, ranging, for example, from difficulties adjusting behavior to suit various social contexts; to difficulties in sharing imaginative play or in making friends; to the absence of interest in peers.

[B] Restricted, repetitive patterns of behavior, interests, or activities, as manifested by at least two of the following, currently or by history (examples are illustrative, not exhaustive; see text):

  1. Stereotyped or repetitive motor movements, use of objects, or speech (e.g., simple motor stereotypes, lining up toys or flipping objects, echolalia, idiosyncratic phrases).
  2. Insistence on sameness, inflexible adherence to routines, or ritualized patterns of verbal or nonverbal behavior (e.g., extreme distress at small changes, difficulties with transitions, rigid thinking patterns, greeting rituals, need to take the same route or eat the same food every day).
  3. Highly restricted, fixated interests that are abnormal in intensity or focus (e.g., strong attachment to or preoccupation with unusual objects, excessively circumscribed or perseverative interests).
  4. Hyper- or hyporeactivity to sensory input or unusual interest in sensory aspects of the environment (e.g. apparent indifference to pain/temperature, adverse response to specific sounds or textures, excessive smelling or touching of objects, visual fascination with lights or movement).

If you are seeking autism evaluations and diagnostic assistance in the Houston, San Antonio, Austin, or Denver region, please reach out to us by submitting a brief form. Schedule your evaluation today!

READ MORE: Concerned about Autism? Identifying Common Signs and Symptoms

DSM-5 Criteria for Attention Deficit Hyperactivity Disorder (ADHD)

People with ADHD show a persistent pattern of inattention and/or hyperactivity-impulsivity that interferes with functioning or development. The following criteria must be met to meet the criteria for ADHD

1. Inattention: Six or more symptoms of inattention [from the list below] for children up to age 16 years, or five or more for adolescents aged 17 years and older and adults; symptoms of inattention have been present for at least 6 months, and they are inappropriate for developmental level:

  • Often fails to give close attention to details or makes careless mistakes in schoolwork, at work, or with other activities.
  • Often has trouble holding attention on tasks or play activities.
  • Often does not seem to listen when spoken to directly.
  • Often does not follow through on instructions and fails to finish schoolwork, chores, or duties in the workplace (e.g., loses focus, side-tracked).
  • Often has trouble organizing tasks and activities.
  • Often avoids, dislikes, or is reluctant to do tasks that require mental effort over a long period of time (such as schoolwork or homework).
  • Often loses things necessary for tasks and activities (e.g., school materials, pencils, books, tools, wallets, keys, paperwork, eyeglasses, mobile telephones).
  • Is often easily distracted.
  • Is often forgetful in daily activities.

​​​​​2. Hyperactivity and Impulsivity: Six or more symptoms of hyperactivity-impulsivity [from the list below] for children up to age 16 years, or five or more for adolescents aged 17 years and older and adults; symptoms of hyperactivity-impulsivity have been present for at least 6 months to an extent that is disruptive and inappropriate for the person’s developmental level:

  • Often fidgets with or taps hands or feet, or squirms in seat.
  • Often leaves seat in situations when remaining seated is expected.
  • Often runs about or climbs in situations where it is not appropriate (adolescents or adults may be limited to feeling restless).
  • Often unable to play or take part in leisure activities quietly.
  • Is often “on the go” acting as if “driven by a motor”.
  • Often talks excessively.
  • Often blurts out an answer before a question has been completed.
  • Often has trouble waiting their turn.
  • Often interrupts or intrudes on others (e.g., butts into conversations or games)

Based on the types of symptoms, three kinds (presentations) of ADHD can occur:

  • Combined Presentation: if enough symptoms of both criteria inattention and hyperactivity-impulsivity were present for the past 6 months
  • Predominantly Inattentive Presentation: if enough symptoms of inattention, but not hyperactivity-impulsivity, were present for the past six months
  • Predominantly Hyperactive-Impulsive Presentation: if enough symptoms of hyperactivity-impulsivity, but not inattention, were present for the past six months.

Autism and ADHD

Based on the criteria for an autism spectrum disorder or ADHD diagnosis, some of the symptoms of each disorder can show up in similar ways. For instance, having difficulty focusing for someone with ADHD can look like a person not paying attention to what someone else is saying. This same behavior can appear in someone with autism as it relates to difficulty with back-and-forth conversation and other social skills.

In 2014, researchers found that between 30 to 50 percent of people with ASD also have symptoms of ADHD. They are unsure why this is although there may be a gene that links both ASD and ADHD symptoms making it more common in people with this gene. However, it is also likely that both autism and ADHD can show up in certain behaviors and, therefore, contribute to the appearance that someone has either one or both conditions.

Getting Support

It is ideal to have trained professionals evaluate you or your loved one for autism spectrum disorder or attention deficit hyperactivity disorder or both so that you receive treatment according to what you are truly experiencing.

If you are looking for autism evaluations and diagnostic support in Houston, San Antonio, Austin, or Denver area, contact us by submitting a short form to schedule an evaluation today.

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  1. American Psychiatric Association. Diagnostic and statistical manual of mental disorders. 5th ed. Arlington, VA: American Psychiatric Association; 2013.
  2. Leitner Y. (2014). The co-occurrence of autism and attention deficit hyperactivity disorder in children – what do we know?. Frontiers in human neuroscience8, 268.
  3. Lionel, A. C., Crosbie, J., Barbosa, N., & Goodale, T. et. al. (2011, August 10). Rare Copy Number Variation Discovery and Cross-Disorder Comparisons Identify Risk Genes for ADHD. Science Translational Medicine. Retrieved April 23, 2022, from
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