Asperger’s syndrome and ADHD are two conditions that both involve brain development. They tend to develop early in life and may cause some similar behavior traits.

The medical community, as of 2013, no longer diagnose Asperger’s syndrome as a separate condition. Instead, they place it under the umbrella term of autism spectrum disorder (ASD). People have typically used the term Asperger’s syndrome to refer to mild forms of autism or “high-functioning” autism.

In an article in the Asperger/Autism Network, one doctor writes that, in her experience, some 60–70% of people with Asperger’s syndrome have characteristics doctors also associate with ADHD.

Despite some similarities, ASD and ADHD, the full name of which is attention deficit hyperactivity disorder, are very different conditions with different causes.

In this article, we discuss the differences between ASD and ADHD, their characteristics, and how doctors diagnose them.

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Despite the potential to cause some similar behavioral traits, ASD and ADHD are two distinct conditions.

In a nutshell, autistic people have difficulty understanding or responding to social norms and cues. A person may become overly interested in a topic or object. On the other hand, people with ADHD have underlying difficulties with attention, hyperactivity, and may have problems with impulsivity.

ASD and ADHD are both neurodevelopmental disorders, according to the American Psychiatric Association. However, ADHD is not a spectrum disorder like ASD.

ADHD is more common than ASD.

Doctors may have difficulty working out whether an autistic child has ADHD or ASD. However, many behavior traits differ between the two conditions.

Autistic people and those with ADHD may notice the following characteristics:

  • difficulty regulating attention
  • trouble following social rules and understanding social cues or norms
  • high impulsivity

Behavior traits that occur in ASD but not ADHD include:

  • having an intense interest in one topic or object
  • different speech or language traits from neurotypical people, such as speech without inflection or trouble controlling volume or pitch
  • trouble understanding humor, irony, or sarcasm
  • difficulties understanding the give-and-take of conversations or seeming to be engaged with conversations, although some people with ADHD may interrupt others who are talking
  • trouble showing empathy
  • trouble making eye contact and other nonverbal communication, such as facial expressions or body gestures
  • trouble understanding social rules
  • developmental delays in motor skills in some cases

Behavior traits that occur in ADHD but not ASD include:

  • trouble focusing or paying attention to details
  • being easily distracted and forgetful
  • trouble following instructions and finishing schoolwork, job duties, or chores
  • daydreaming often
  • taking physical risks or playing too rough
  • being impatient and having trouble sitting still during quiet activities
  • understanding but breaking rules or not listening to directions

How pronounced and numerous a person’s difficulties can help distinguish ASD from ADHD. For example, autistic children can find socializing more difficult than children with ADHD due to problems interpreting and responding to social cues and norms.

Autistic people can have ADHD. According to the CDC, some 14% of children with ADHD have also been diagnosed with Autism spectrum disorder.

Every autistic person is different. Some people have mild difficulties with communication and language, while others have more pronounced problems.

Individuals with ASD can have an obsessive interest in a specific object or topic, though not everyone experiences this. They may learn everything they can about an object or topic and have little interest in pursuing or discussing much else.

Autistic people may also have the following traits:

  • repetitive rituals or routines
  • different speech or language traits from neurotypical people
  • different social and emotional responses from neurotypical people
  • difficulty interacting with others
  • clumsy or uncoordinated motor movements, such as a walk that appears bouncy or tilted
  • problems interpreting and responding to non-verbal communication, such as facial gestures or expressions
  • increased anxiety or depression

Some people with ADHD experience ongoing patterns of inattention, impulsivity, or hyperactivity, or they may experience all of these behaviors that cause them problems with social or occupational functioning.

People with ADHD may experience:

  • daydreaming often
  • forgetfulness, losing things often
  • taking unnecessary risks or making careless mistakes
  • difficulties with resisting impulses or temptations
  • trouble following directions or rules
  • fidgeting or touching everything around them
  • trouble with quiet tasks or sitting still
  • impatience or having a hard time waiting, sharing, or taking turns

Currently, there are no specific scientific tools, such as blood tests, to diagnose ASD or ADHD. Researchers are working on ways to use brain-imaging tools to identify both conditions.

Healthcare professionals specializing in childhood neurodevelopmental conditions will usually diagnose ASD and ADHD. They include:

  • pediatricians
  • neurologists
  • nurse practitioners
  • developmental-behavior pediatricians
  • child psychiatrists
  • child psychologists
  • pediatric neuropsychologists
  • clinical child psychologists

To diagnose ASD and ADHD, one or more doctors will observe children and take a complete personal and medical history.

Doctors may do tests to look for difficulties with learning, sensory processing, or motor skills. These include verbal, visual, hearing, and physical tests. These tests can rule out or diagnose other conditions.

Historically, healthcare professionals identified Asperger’s syndrome later than other forms of ASD because children do not experience intellectual or language delays. Signs of this form of autism may not appear until a child enters more challenging social settings, such as school.

As with ASD, doctors usually diagnose ADHD when children enter complex learning environments, such as school. At other times, a diagnosis may not happen until adulthood.

Health experts may base a diagnosis on patterns of inattention, hyperactivity, and impulsivity that last longer than 6 months and occur more frequently than in other children.

Most experts agree that there is no cure for ASD. Many people with ASD do not see autism as something that doctors need to cure or that they need treating. People can, however, improve any health conditions they associate with ASD and take steps to reduce any daily difficulties of ASD.

In many cases, the sooner people receive a diagnosis of ASD or ADHD, the better their chances are of reducing problems with school, jobs, and interpersonal relationships.

Some people use the following therapies, with varying degrees of success, to manage ASD:

  • behavioral analysis
  • speech therapy
  • social skills training classes
  • physical therapy
  • occupational therapy
  • sensory integration therapy or a sensory diet
  • medications to help manage anxiety, depression, and other existing conditions, such as ADHD
  • adjusted school routines

Some people use the following therapies to manage ADHD:

  • behavioral therapy
  • CBT
  • educational and organizational coaches
  • ADHD medications
  • adjusted school routines

ASD and ADHD can cause similar behavior traits. However, they are different conditions with different causes. People may use behavior therapies to help manage any challenges or conditions that health professionals associate with both ASD and ADHD.