Autism and ADHD: Neurological Cousins3 min read

October is ADHD Awareness Month!

In the six months or so leading up to the assessment in which I was diagnosed as autistic, I had first “self-diagnosed” with ADHD.  A friend suggested it to me, and the more I read, the more I related, and the more everything in my life that hadn’t made sense for 28 years fell into place.

It took probably a year and a half post-assessment before I really started looking into the autism side of my diagnosis.  In my written report, my (very excellent) psychologist had suggested that doing so may help me to understand myself better.  She was spot on!

Having immersed myself in ADHD literature before switching over to reading about autistic people, I like to believe that I have a pretty good grasp of what characterizes each condition, but like with many neurological disorders, there is a lot of overlap.

“Attention deficit” is not entirely accurate…

Like autism, ADHD is characterized mainly by what diagnosticians have observed, rather than what the person actually experiences.  Challenges with focusing, hyperactivity, and impulsivity are the most noticeable traits, but for many ADHDers, these aren’t actually their primary challenges, and many say that ADHD is a misnomer.

ADHDers have what has been called an “interest-based nervous system.” We might have difficulty concentrating on something difficult or uninteresting, but we can also hyperfocus on the things that we’re really into.  The real experience of ADHD is not a deficit of attention, but an inability to regulate it.

Hyperactive on the outside; restless on the inside.

Hyperactivity in ADHD often changes as we grow into adults, and we are instead more likely to have restless thoughts.  Along with that comes impulsivity, the other “defining” trait of ADHD.

Between the restless thoughts and difficulty concentrating, it’s easy to just do without thinking.  ADHDers say things we would prefer to take back immediately; we’re prone to buying things without thinking it through first; and we are very much at risk of forming addictions.

Executive functioning is at the core

However, like autism, the criteria in the DSM for ADHD consist mainly of what psychologists have observed, rather than what the person actually experiences.  Challenges with focusing, hyperactivity, and impulsivity may be the most noticeable traits, but the core traits underlying these have to do with our executive functioning system of the brain.

ADHD expert Dr Thomas E Brown divides the executive functions that are impaired in ADHD into the following “clusters:”

  1. Activation: Organizing, prioritizing, and activating to work.
  2. Focus: Focusing, sustaining, and shifting attention to tasks.
  3. Effort: Regulating alertness, sustaining effort, and processing speed.
  4. Emotion: Managing frustration and modulating emotions.
  5. Memory: Utilizing working memory and accessing recall.
  6. Action: Monitoring and self-regulating action.

Challenges with these areas will probably be familiar to autistic readers, even those who aren’t also diagnosed with ADHD.  As neurodivergent cousins, we experience quite a bit of overlap in traits.

For example…

We both hyperfocus on what interests us.  ADHDers may experience more difficulty concentrating on what doesn’t interest them.  Autistics may dive a little deeper into our special interests, and these interests may last a much longer time.

We both have sensory sensitivities.  ADHDers are easily distracted by extraneous stimuli that others are able to filter out.  Autistic people may or may not be as easily distracted as ADHDers, but depending on whether they are hyposensitive or hypersensitive to a particular sense, they are able to hear or see things that others miss.

We both have challenges with emotional regulation and low frustration tolerance.  The underlying reasons may be different.  ADHDers dealing with restlessness may have less patience for something aggravating.  Autistic people may lash out when experiencing sensory overload.

And we both stim!  ADHDers jiggle their legs, twiddle their thumbs, doodle while taking notes, twirl their hair, and are constantly on the move to relieve the tension of hyperactivity.  Autistic people stim for a wider variety of reasons, and autistic stimming seems to be a little bit less like “typical” fidgeting (e.g., hand flapping).

There is much more overlap, but when you’re diagnosed with both, it can be hard to separate the two.  In fact, I once read that ADHD could be considered part of the autism spectrum given how often they co-exist.  Perhaps one day we’ll see ADHD as an autistic “profile.”

Until then, it’s all neurodivergence to me!

Ren Everett

Autist in Ontario, Canada.
My full-time job right now is to concentrate on improving my mental and physical health by taking it slow, improving my understanding of myself, and learning more about what I can offer that is valuable to the community at large.
Ren Everett

1 Comment

  1. Thanks Ren:

    I imagine this post will get a lot of people thinking.

    Especially with all the similarities.

    And how important it is to put people’s experiences at the heart of everything.

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