Dr. Amy Marschall, Psy.D

Hyperactivity, social difficulties, hyperfocus, and impulsivity. The overlapping symptoms between ADHD and Autism don’t stop there but they are often under-recognized in patients who could benefit from a specific diagnosis and treatment plan.

ADHD and Autism are not mutually exclusive

But until 2013, these two lifelong conditions were thought to never occur together. Which means that not only were patients presenting with ADHD not evaluated for autism (and vice versa), but the idea that they should be was not considered. Thankfully, we now know that they can co-occur and might even share some causation and roots.

ADHD and Autism frequently occur together

Research indicates that approximately 10% of people have ADHD, while about 3% are autistic. But the overlap between these conditions is significant—40-70% of autistic individuals also have ADHD, and nearly half of those with ADHD may be autistic. This co-occurrence is sometimes referred to as AuDHD.

Not everyone with ADHD is autistic, and not all autistic individuals have ADHD. Properly identifying each condition and identifying the overlap is crucial for providing the right support and treatment. While each person will experience a different balance of symptoms, some of the most common that appear in both ADHD and autism include:

• Social Difficulties: Both groups may struggle with social interactions due to their neurodivergent traits.
• Movement and Vocalization: This includes hyperactivity, fidgeting, or stimming behaviors like humming or whistling.
• Hyper-focus: Individuals might intensely focus on specific tasks or interests, sometimes to the exclusion of everything else.
• Academic Challenges: Both ADHD and autism can lead to struggles in a traditional academic setting.
• Self-Care Difficulties: Activities like maintaining hygiene can be more challenging for individuals with these neurodivergences.

The Connection Between ADHD and Autism

What Does AuDHD Look Like?

Just like ADHD and autism individually, each individual with AuDHD has unique symptoms. Still, though there is no single way to identify AuDHD, some indications include: include:

• Difficulty with Routine: Struggling to maintain a set schedule, even when routines are beneficial.
• Intolerance to Change: Difficulty adapting to changes unless they initiate them.
• Impulsivity: Engaging in impulsive behaviors, such as risk-taking or seeking activities that provide a dopamine rush.
• Shifting Interests: Intense focus on new hobbies or topics that may be quickly abandoned.
• Interruptive Behavior: Frequently interrupting others during conversations or blurting out thoughts.

Diagnosing AuDHD

Many healthcare providers are trained to identify ADHD and autism separately and therefore may lack the training to recognize where the two overlap. This can lead to misdiagnosis, particularly in individuals who don’t fit the typical profiles, such as women, people of color, or those from different socioeconomic backgrounds.

If you suspect you might have both ADHD and autism, it’s crucial to find a provider experienced in diagnosing these conditions together. A thorough evaluation may include:

• History Taking: Providers might ask about your developmental history and the specific traits you experience.
• Collateral Information: They may want to speak with someone who knows you well or knew you as a child, though this isn’t always necessary.
• Psychological Testing: You might complete questionnaires or other assessments to help clarify your neurodivergent traits.

Because the intersection of ADHD and autism is still underrecognized, many people with AuDHD aren’t diagnosed until later in life. However, seeking a diagnosis and support tailored to your unique needs is never too late.

Dr. Marschall is a licensed clinical psychologist who specializes in diagnosing ADHD and autism across the lifespan. She is an author, speaker, and advocate for neurodiversity-affirming care and improving access to accurate diagnoses and mental health support for the ADHD and autistic communities. She owns a private practice providing assessments and therapy. She was diagnosed with ADHD and autism as an adult.