What's the Difference Between ADHD vs. Autism?

Many disorders share similarities or traits and symptoms that overlap. This can be true for ADHD and Autism Spectrum Disorder. What’s the difference between ADHD vs. Autism, and is it possible to have both (also known as co-occurrence)? How is each developmental disorder treated?

In this article, we’ll address the answers to those questions and discuss what to do if you believe that you or someone in your care has ADHD or Autism.

What is ADHD?

ADHD is short for attention-deficit/hyperactivity disorder. It is a neurodevelopment disorder that is characterized by clinically significant symptoms of inattention, hyperactivity/impulsivity, or a combination of both.

With challenges such as forgetfulness, interrupting others without meaning to, trouble remaining still, and difficulty staying engaged in tasks that require sustained focus, ADHD can affect interpersonal relationships, work, school, and other areas of life.

What is Autism?

Like ADHD, Autism Spectrum Disorder (ASD) is a neurodevelopment disorder. However, this disorder differs in symptoms when compared to ADHD. Autism is characterized by differences in social communication/interaction and repetitive or restrictive patterns in behavior, interests, or activities.

Symptoms of ADHD and Autism

As you can see, although there are some similarities between ADHD and Autism, there are significant differences as well, and although some traits may look similar from the outside looking in, the cause of that sign, symptom, or trait could be different.

For example, a person with ADHD may face challenges with a task due to limited abilities to sustain their attention, whereas a person with ASD may hone in on specific topics of interest or subjects and face challenges with tasks outside of these areas.

Understanding the symptoms that the two conditions are characterized by and diagnosed based on can help. As for whether or not someone can have both, the answer is “yes.” While this was not always the case, we now have research to confirm that this is true, and an individual can receive a diagnosis of both ADHD and ASD.

ADHD Symptoms

ADHD symptoms fall into two different categories. The two categories of symptoms they can fall under are inattention and hyperactivity/impulsivity.

Inattention symptoms include:

• Frequent forgetfulness in daily activities.
• Frequently fails to provide close attention to detail or makes seemingly careless mistakes in school, at work, or within the context of other activities.
• Frequent challenges trouble holding attention to tasks or play activities.
• Frequently appearing as though one is not listening when they’re spoken to directly.
• Frequent failure to follow through on instructions and finish schoolwork, chores, or other responsibilities, such as those in the workplace.
• Frequent challenges with organizing tasks and activities.
• Frequently avoids, dislikes, or feels reluctant to engage in tasks that require sustained mental effort (such as schoolwork/homework).
• Frequently loses items that are necessary for tasks and activities (IE, school supplies, wallets, car or house keys, tools, paperwork, eyeglasses, cellphones).
• Is frequently easily distracted.

Hyperactivity/impulsivity symptoms include:

• Frequently fidgets, taps hands or feet, or squirms while seated.
• Frequently leaves one’s seat in situations when remaining seated is expected.  
• Frequently running or climbing in situations where it is not appropriate (in adolescents or adults, this could be limited to feeling restless).
• Is frequently unable to play or engage with leisure activities quietly.
• Is frequently “on the go” or acts as if they are “driven by a motor.”
• Frequently talks excessively.
• Frequently blurts out answers before a question has been completed.
• Frequent trouble waiting for one’s turn.
• Frequently interrupts or intrudes on other individuals (IE, inserts self into other people’s conversations/games).

If someone is under 17 years of age at the time of an ADHD diagnosis, they must meet at least six symptoms in one or more of the above areas. So, for example, someone might experience at least six symptoms of inattention and could receive a diagnosis of ADHD.

Autism Symptoms

Autism Spectrum Disorder symptoms include:

1. Ongoing challenges in language skills, social communication, and interaction across various contexts as defined by the following:

• Differences in social-emotional reciprocity (may include failure to start or respond to social interactions, an abnormal social approach, or reduced sharing of emotions and/or affect).
• Deficits in behaviors associated with nonverbal communication.
• Difficulty maintaining eye contact
• Trouble developing, maintaining, and understanding social relationships.

2. Repetitive and restrictive patterns of behaviors, interests, or activities as defined by the following:

• An insistence on sameness or inflexibility with regard to one’s routines.
• Atypically restricted, fixated interests.
• Hyper-reactivity or hypo-reactivity to sensory input, or an unusual interest in sensory aspects of one’s environment.
• Repetitive behaviors or body/motor movements, speech (echolalia), or use of objects.

If you believe that you or your child may be autistic, have ADHD, or another condition, make a healthcare appointment with a pediatrics professional (such as a pediatrician) who can offer guidance and help you take the next steps.  

Diagnosis

Only a qualified medical professional can diagnose ADHD and Autism. When an evaluation takes place, a professional will go over a client’s history and symptoms and will rule out any other potential causes of their symptoms.

A diagnosis will occur based on the criteria in the most recent version of the diagnostic and statistical manual of mental disorders (DSM). Currently, this is the DSM-5. While both disorders can be diagnosed at any point in time, symptoms will begin in childhood (for ADHD, before the age of 12). A proper diagnosis matters and is often the first step to receiving adequate treatment.

Causes

For both ADHD and Autism, there’s no one singular cause to ADHD and ASD. Anyone can have them. However, there are possible risk factors that can increase the likelihood.

Risk factors associated with a higher risk of ADHD include:

• Genetics (family history of ADHD)
• Environment (IE, air pollution).
• Low birth weight and/or being born prematurely.

Risk factors associated with a higher risk of Autism include:

• Genetics (family history of ASD).
• Environment (IE, air pollution).
• Low birth weight and/or being born prematurely.
• Parental age.

Is There a Connection?

Although not everyone with ADHD has an additional diagnosis of Autism Spectrum Disorder, there does appear to be somewhat of a connection. Some disorders are seen at a higher rate in individuals who live with ADHD, and Autism Spectrum Disorder is one of them.

Research indicates that around 50-70% of individuals with a diagnosis of Autism Spectrum Disorder also have ADHD. So, if that’s the case for you or someone else you know, you most certainly aren’t alone!

When an individual meets the criteria for both ADHD and Autism, their treatment plan may include support for both.

Treatment

Both ADHD and Autism do not have a cure. However, there are forms of treatment and methods of support that can be helpful for those who live with ADHD, Autism, or a combination of the two.

ADHD Treatments

It’s common for individuals who live with ADHD to engage in more than one treatment option. For example, someone may take medication and engage in therapy. ADHD treatments can include:

• Medication
• Behavior and/or mental health therapy
• Occupational therapy for ADHD
• Social skills training
• Educational and/or school-based support
• Games and apps
• Lifestyle interventions
• Parent training

Autism Treatments

There is no singular standard treatment for ASD, but there are many things that can improve a person’s functioning and quality of life. Treatment can vary substantially from person to person based on their unique symptoms and any co-occurring concerns that they might live with.

Here are some forms of treatment used for ASD:

• Joint attention therapy
• Occupational therapy
• Behavioral therapy and/or mental health therapy
• Executive functioning skills training
• Parent education or training
• Speech-language therapy and activities

Similar to ADHD, school-based and/or educational tools, treatments, and support options can also be beneficial. School and social situations can be challenging for individuals who live with ASD, as can emotional regulation, navigating relationships in adult life, and implementing at-home tools and regimens that can help with functioning.

Professional care from someone who specializes in working with ASD can be key. Events for people with disabilities, as well as independent living opportunities and other forms of support, can help people connect with others and live an independent, successful life that they are proud of.

Since Autism Spectrum Disorder can range in symptoms in severity, some people with ASD may need more or less help (or different kinds of help) than others will. For example, some might be non-verbal or partially non-verbal, whereas others will not be non-verbal or partially non-verbal.

Other common conditions that can appear in those with Autism, ADHD, or both can include but aren’t limited to anxiety disorders, substance use disorders, learning disabilities, depression, and eating disorders. This can inform a person’s treatment plan.

Summary

ADHD and Autism aren’t the same disorder. However, it is possible to have both (co-occurrence). There are various forms of support available for people who live with ADHD or Autism. The most suitable treatment plan for both disorders will depend on the unique needs of the individual.

This article is for informational purposes and is not a substitute for individual medical or mental health advice. Please consult with your or your child's prescribing doctor before changing, starting, or stopping a medication routine.