AuDHD is a grassroots term that arose from the neurodivergent community—largely through usage in social media—as a means to identify, learn about, and advocate for people who have both autism and ADHD.
There are surprisingly little data on the co-occurrence of autism and ADHD because these two conditions were not allowed to be diagnosed in the same individual until the publication of the DSM-5 in 2013. Prior to DSM-5, if an individual was diagnosed with autism, it was not possible for them to also be diagnosed with ADHD.
About 5 to 8 percent of children have ADHD and 2 to 4 percent have autism, according to recent literature reviewed by Canals et al. (2024). If autism and ADHD were independent of one another, it’s estimated that about 0.2 percent of children would have both conditions. But autism and ADHD occur together much more than one would expect based on chance.
In a review of 63 studies, about 40 percent of autistic people had an ADHD diagnosis (Rong et al., 2021). In a more recent study from Spain, 46 percent of school-aged children with autism had ADHD and about 10 percent of children with ADHD had autism (Canals et a., 2024). Even children with sub-threshold autistic traits had a high rate of ADHD diagnoses.
Thus, it appears that the two conditions—which until recently were not formally diagnosed in the same individual—co-occur frequently. I suspect this rate might be an underestimate due to the fact that challenges with executive functions and attention are core features of both conditions.
When an individual has autism and ADHD, the challenges of living in a culture that is not equipped to embrace neurodiversity can be magnified. Social interactions can be more challenging, daily living skills can be harder to master, emotions can be more difficult to regulate, and well-being can suffer (as reviewed in Canals et al., 2024).
In one study, adolescents with AuDHD had more challenges than autistic adolescents without ADHD on measures of executive functions, taking the perspective of another person, and emotional and behavioral regulation (Rosello et al., 2023). AuDHD also had more learning difficulties. The authors asserted that executive functions, impulsivity, and challenges with regulation are important to assess in autistic children and may be why AuDHD adolescents had relatively more difficulties than autistic adolescents.
In 2024, Emma Craddock wrote a commentary to elevate the voices of girls and women with AuDHD. She visualized the synergy that having autism and ADHD presents. “We might imagine autism as the colour red, ADHD as the colour blue, and AuDHD as purple—more than a sum of its parts; a thing in and of itself,” (Craddock, 2024, p. 2163).
Autism and ADHD are more than the sum of their parts. Efforts to raise awareness and advocate for more understanding for AuDHD are vital to maximizing well-being. Early identification of ADHD in autistic children and especially the assessment of executive functions can help identify the appropriate supports and ensure the best developmental outcomes.
