6 Ways ADHD Hides Autism

There are many reasons why an autistic or ADHD person might go missed for years.

If you’re an adult who’s only recently started making sense of your own neurodivergence, then you’ve lived through multiple cultural and diagnostic shifts, changes to the diagnostic criteria, and a growing emphasis on lived experience.

There’s been more recognition of what autism and ADHD look like in adults, and much deeper awareness of nuanced presentations and masking.

One of the other things that can complicate or delay a diagnosis, especially an autism diagnosis, is when both ADHD and autism are present.

That’s what we’re looking at today: how the overlap between autism and ADHD can lead to misdiagnosis, late diagnosis, and a lot of self-doubt.

Along the way, we’ll unpack what diagnostic overshadowing is, the research we do have about a delay in diagnosis, and we’ll walk through six ways that ADHD can overshadow autism.

I am Dr. Megan Anna Neff. I’m an autistic ADHD clinical psychologist, founder of Neurodivergent Insights, and the author of Self-Care for Autistic People and the Autistic Burnout Workbook.

I’m currently deep in the research and writing phase of my next book, AuDHD Unlocked, and this video series gives you a window into some of what I’m finding and thinking along the way.

Now, the statistics range quite a bit depending on which study you look at, but estimates suggest that roughly 30 to 80% of autistic people also meet criteria for ADHD, and about 20 to 50% of people with ADHD are also autistic.

Unfortunately, diagnostic systems are built on an either-or categorical framework, and so when overlap happens, that can create some unique problems.

It sets the stage for what’s called diagnostic overshadowing. That’s when one diagnosis hides another condition that is also present.

What that means for our lives is that many of us don’t slot neatly into autism or ADHD alone. We’re often living at that complex intersection where traits blend, blur, and sometimes hide each other.

Now, the diagnostic tools that we have available to us are often built around neat lists of checkboxes or more of that categorical thinking. So if you’re autistic and ADHD, you might not fit cleanly into the autism boxes, and you also might not fit cleanly into the ADHD boxes either.

So you can end up falling through the cracks between these two categories.

Now, across multiple studies, a clear pattern has been shown that when ADHD is first identified for someone who’s both autistic and ADHD, it results in a delay in identification of the autism.

So, for example, one large European study found that children who had an ADHD diagnosis before the autism diagnosis, on average it took 1.8 years longer for the autism to be identified.

When researchers broke this down by gender, boys with prior ADHD received an autism diagnosis about 1.5 years later, while girls waited closer to 2.6 years, and then clinical reports and case studies and lived experience also echo this pattern.

Many describe children and teens who first carried an ADHD diagnosis, and only after years of unmet needs and struggle and often mental health challenges did autism finally make it into the conversation.

And then these numbers also sit on top of other disparities that we know about. For example, we know that Black and brown children tend to receive both autism and ADHD diagnoses later and after more clinical encounters than white children.

So it’s reasonable to assume that when ADHD is picked up first in these communities, the delay in recognition of the autism likely stretches even further for them.

So then when it comes to autism recognition, there are at least four overlapping delays that AuDHDers may experience.

First of all, a delay tied to ADHD being recognized first, and then the diagnostic overshadowing that happens.

There can also be a delay tied to gendered expectations, and then a lot of the tools that we have available to us were built and designed around the experiences of boys.

There’s a delay that is tied to racial inequality and unequal access to assessment and care.

And then across the gender spectrum, masking adds another layer where a lot of autistic and ADHD traits tend to fly just under the threshold or under the radar of what clinicians are looking for.

So for many ADHD adults, this helps explain why our diagnostic story feels so fragmented. Perhaps you received a childhood ADHD diagnosis, and then maybe anxiety or depression was added in adolescence, and only much later does autism enter the conversation.

And then of course, for others, both ADHD and autism were completely missed in childhood and only entered the conversation in adulthood.

This is what we often refer to as the lost generation of autistic adults or the lost generation of ADHD adults.

Now, if we look at the diagnostic overshadowing when ADHD is overshadowing the autism, then here are six ways that ADHD can hide the autism. From the outside, ADHD can be pretty loud and colorful, and that can quickly drown out the autism. So while this certainly isn’t an exhaustive list, here are six ways that this can happen.

First, social behavior can look ADHD enough that autism is never even considered. For example, a child might be struggling socially. Maybe they interrupt their peers or talk over others or blurt out responses in class. This is often seen as part of a broader pattern of ADHD.

So maybe the person is struggling socially or they’re struggling to connect with their peers, but it’s interpreted and read as impulsive. On top of the ADHD, they might also be missing social cues or context cues and struggling to interpret other people’s emotions or signals. But all of that gets framed as part of ADHD inattention or ADHD impulsivity.

And then once ADHD seems to fit, clinicians, parents, and teachers might stop asking those deeper questions. Some of those more subtle social communication differences are again flying under the radar, or all the social struggles that that person is having are getting attributed to ADHD alone.

Now, a second thing that can happen is where movement and sensory seeking often get framed as hyperactivity or restlessness. So fidgeting and pacing or just being in constant motion can easily be understood as hyperactivity. When that happens, the underlying sensory drivers, so perhaps stimming or needing movement to regulate or seeking certain repetitive sensations, go unnoticed.

A child might be spinning or climbing or seeking deep proprioceptive pressure, and that all might get interpreted as the person being overactive rather than as someone who is seeking proprioceptive input or maybe they have some unmet vestibular sensory needs, which is why they’re spinning. So all of this, which we see in autism, can be hidden under the framework of hyperactivity in ADHD.

A third one is when executive functioning struggles are attributed solely to ADHD. Difficulties with planning, transitioning, or shifting our attention all rely on executive functioning, and these are classic experiences in the ADHD picture, but they can also be connected to autism, though often for different reasons.

For example, autistic people tend to be bottom‑up processors, meaning that we absorb a lot of details, and so we can easily get cognitively whelmed and overloaded, which makes a lot of those decisions or shifting of attention more difficult, but for slightly different reasons. Additionally, when we are sensory overloaded, that’s also going to impact our executive functioning.

So again, that aspect of executive functioning struggle or decision fatigue or difficulty with planning might get chalked up to ADHD executive functioning, when actually there are autistic drivers in the mix. If ADHD is already on the chart, then those struggles are going to get explained through executive functioning, and the ways that bottom‑up processing or our sensory processing are contributing to that are going to remain unseen.

Fourth, the need for security, predictability, and routine can get interpreted through an ADHD emotional lens. For autistic people, it’s really common to have a lot of distress around sudden change or unpredictability, things we weren’t expecting. However, these responses can get interpreted as emotional reactivity or “poor frustration tolerance.”

These are things that we often see coming along with the picture for ADHD, and so these reactions to routine disruptions or distress might get interpreted as simply ADHD emotion‑regulation difficulties. Again, when ADHD is the first label, shutdowns a person might be having during transitions, or distress they might be showing in response to routine disruption or schedule changes, can all get misread as behavioral issues rather than an autistic response to uncertainty or unexpected change or routine disruption.

Similarly, sensory distress could also be interpreted through that same emotional lens. For example, a child might have a meltdown when a parent tries to brush their hair or brush their teeth or help them get dressed, and they might be having a sensory response. However, if that child is known to be ADHD, the parent might interpret that as difficult behavior in the context of ADHD.

A fifth way that ADHD can hide the autism is when special interests get missed and folded into ADHD interest patterns. Deep, focused interests are a huge part of the autistic experience. However, in ADHD it’s also common to have hyperfocus and have passions, and so special interests can get chalked up to hyperfocus.

Then less attention might get paid to how narrow or immersive or regulating those interests are. A clinician might write “gets very absorbed in preferred activities, ADHD hyperfocus,” but if they never ask how those interests function socially, emotionally, or sensory‑wise—which are key to understanding their role in the autistic experience—then that’s another part of the person’s experience that can easily get missed and attributed to the ADHD.

And finally, masking can hide what’s underneath. Many AuDHDers become pretty skilled at using their ADHD traits—things like humor or playfulness or quick speech or storytelling—to kind of perform sociability, and that can smooth over some of the autistic social anxiety or confusion that we often see in the autistic experience.

On paper, this can look like the person’s really friendly and talkative, and it looks like talkative ADHD, but the autistic person beneath it is often carefully scripting or rehearsing or collapsing afterward. In each of these scenarios, the ADHD explanation isn’t completely wrong, but it isn’t complete, and when it becomes the whole story, that’s when the autism is overshadowed.

When this happens, that’s what we call diagnostic overshadowing, where the autistic traits get attributed to the ADHD. In AuDHD, it is more common for the ADHD to overshadow the autism. However, it can go both ways.

So overshadowing between autism and ADHD can show up in several different ways. Autistic sensory overload can be labeled ADHD overwhelm or emotion dysregulation, and the sensory and predictability needs underneath are never named.

Going the other way, when the autism is known but the ADHD is not, forgetfulness and time‑perception struggles could get framed as autistic rigidity or autistic shutdowns or autistic cognitive overload, and then the ADHD‑related executive‑functioning differences go unseen.

On top of all of that, global experiences like shutdowns or meltdowns or burnout are often explained through one lens alone—“that’s just the autism” or “that’s just the ADHD”—rather than seeing them as a cumulative effect of both interacting together. When this kind of diagnostic overshadowing happens, support can miss the mark, especially when the underlying neurology and the support needs that flow from that are never fully seen and supported.

Diagnostic overshadowing is one of the main reasons that so many of us wait so many years before we have a full story to actually understand ourselves in all of our complexity. It can delay identification, and it also tends to delay the ability to set up the appropriate accommodations that we need that could make life feel a lot more possible and doable.

It can deepen shame as many of us repeatedly internalize some form of the message, “I should be able to do this,” when the truth is, the support that we perhaps have received or built around us was never fully designed with all of our neurology in mind.

In the next video, we’ll look at how autism can overshadow or hide the ADHD. While that is a less common experience, that was actually my experience, and so I’m excited to talk about that in the next video.

We’ll talk about how understanding our combined neurology can bring more clarity to our AuDHD stories. Until then, be gentle with yourself, stay curious, and thanks so much for being here.

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