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ADHD and autism together: what you need to know
ADHD and autism are distinct neurodevelopmental conditions, but they can occur in the same person.
Some experiences may appear similar from the outside, while the processes behind them and the support needed may differ.
A screening test cannot diagnose ADHD or autism. A comprehensive assessment considers developmental history, everyday functioning and other possible explanations.
ADHD and autism occur together relatively often. A 2021 review combined the findings of 63 studies. It found that approximately four in ten autistic participants also met the diagnostic criteria for ADHD. Autism-related features may also be more common among people with ADHD, but having these features is not the same as receiving an autism diagnosis. There is no single figure that applies to everyone. Studies have included people of different ages and backgrounds, and the settings and methods used have also varied.
What do AuDHD prevalence estimates mean?
A screening score is not the same as a confirmed diagnosis.
An estimate from one study may not apply equally to every group of people.
ADHD does not automatically mean that autism is present, nor does autism alone mean that ADHD is present.
ADHD and autism are not the same, although some of their features may appear similar. An autistic person may enjoy new experiences, and a person with ADHD may rely heavily on routines.
The following table shows possible patterns rather than diagnostic rules.
How ADHD and autism may differ
When both are present
The purpose of support is to make everyday life more manageable, not to hide signs of ADHD or autism. People with AuDHD may need predictability and flexibility at the same time. Advance notice can be important, while choice and variety may also help. A rigid schedule can provide a sense of safety yet remain difficult to follow over time. Too much variety may feel interesting at first but can also become overwhelming. The most helpful approach will differ from person to person.
What can a screener tell you?
A brief ADHD screener may indicate whether an ADHD assessment could be worth considering. It does not provide a diagnosis, rule out ADHD or show whether someone is autistic. If autism-related features are also present, a separate autism assessment may be helpful. An ADHD assessment alone does not provide an autism diagnosis.
Can I be assessed for ADHD and autism at the same time?
Can one condition mask the other?
Is ADHD a form of autism?
What should I do if both ADHD and autism seem relevant to me?
Our free five-minute ADHD screener may provide a useful indication and some preliminary information. A screener is not a diagnosis and cannot replace consultation with a suitably qualified health professional.
Ready to learn more about ADHD assessment?
Connect with a suitably qualified health professional who can help you explore what may be contributing to your experiences and whether a full ADHD assessment could be helpful.
Types of ADHD: how can they look different?
Not sure how the different ADHD presentations may appear in everyday life? Learn more about types of ADHD, how they vary between people, and when further assessment may be worth considering.
Types of ADHD →
Explore the essentials
This page is part of our wider ADHD series. Each of the following articles explores one part of the topic in more detail.
Understanding the essentials
ADHD presentations
Assessment
This page provides general information only.
It cannot determine whether you have ADHD and it does not replace a full assessment by a suitably qualified health professional with training and experience in ADHD.
Australian ADHD Professionals Association, 2022. Australian evidence-based clinical practice guideline for attention deficit hyperactivity disorder (ADHD). https://adhdguideline.aadpa.com.au/
New Zealand Ministry of Health, 2025. New Zealand clinical principles framework for attention deficit hyperactivity disorder. https://www.health.govt.nz/publications/new-zealand-clinical-principles-framework-for-attention-deficit-hyperactivity-disorder
National Institute for Health and Care Excellence, 2018 (updated 2019, reviewed 2025). Attention deficit hyperactivity disorder: Diagnosis and management (NICE Guideline NG87). https://www.nice.org.uk/guidance/ng87
Centers for Disease Control and Prevention, 2026. ADHD in adults. https://www.cdc.gov/adhd/about/adhd-in-adults.html
CADDRA – Canadian ADHD Resource Alliance, 2020. Canadian ADHD practice guidelines (4.1 ed.). https://www.caddra.ca/canadian-adhd-practice-guidelines
Rong, Y., Yang, C.-J., Jin, Y., & Wang, Y., 2021. Prevalence of attention-deficit/hyperactivity disorder in individuals with autism spectrum disorder: A meta-analysis. Research in Autism Spectrum Disorders, 83, Article 101759. https://doi.org/10.1016/j.rasd.2021.101759