Adult ADHD and Autism

You may have noticed a surge in people around you sharing that they think they may have ADHD or Autism, or have received a diagnosis of one or both neurotypes. It’s not that suddenly more people are neurodivergent than before, but because more people are learning about how their brains work, alongside increased research in these areas.

I did mention the term neurodivergent, which means that someone’s brain works ‘differently’ than other folks who may consider themselves to be ‘neurotypical’. Many folks use the term neurodivergent synonymously with their experiences with ADHD and/or Autism. Many folks make sense of their neurodivergent experiences as a neurotype or a disability.

Many traits of ADHD and Autism overlap with each other, and other traits that are distinct to one of the neurotypes. It is common to experience both ADHD and Autism, which is what some call ‘AuDHD’. Here are some of the similarities and differences in adult ADHD and Autism:

ADHD

-              Inattention

-              Hyperactivity (physical and/or mental)

-              Social struggles may come from distraction or impulsivity

-              Difficulties following through with uninteresting tasks

-              Forgetfulness and misplacing items

-              Difficulty being ‘consistent’ with routines

-              Often craves new experiences

Autism

-              Social communication challenges such as maintaining conversations, interpreting non-verbal communication, implied messages and sarcasm,  and maintaining eye contact

-              Restricted and repetitive behaviours, including the need for strong routine, deep interests in certain topics, repetitive movements (sometimes called “stimming”)

-              Can feel resistant to change in routine

-              Transitions can be challenges

-              Unexpected changes can cause significant distress

-              Autistic meltdowns that stem from overwhelm

-              Common dual diagnoses include certain autoimmune conditions and chronic fatigue

Traits of Both ADHD and Autism:

-              Executive function challenges such as planning, organizing, starting, and finishing tasks

-              Impulsive behaviours

-              Sensory sensitivities such as clothing textures and types of lighting

-              Emotion regulation challenges, such as difficulty managing stress, and difficulty knowing what’s going on in one’s body (also called ‘alexithymia’)

-              Hyper-fixation on interests, or ‘special interests’

-              Sleep issues

- Social challenges

The chart above is a simplified way of explaining these neurotypes. It’s important to note that every neurodivergent person has their unique ‘flavour’ of neurotype, where some people may experience some traits that others don’t, and the intensity of impact ranges between people.

Another layer of complexity to neurodivergence is that women and girls, and folks who have been socialized as girls, have gone unrecognized and undiagnosed for many reasons, including that they’ve been underrepresented in research, their traits often appear more internal, and higher social masking.

When we haven’t known or recognized that we resemble neurodivergent traits, we can negatively internalize messages about ourselves and lack clarity about how you move through the world. While learning about your neurodivergence can be liberating and validating, it can also come with anger and grief for all the time you weren’t aware of this part of you.

Here at Down to Earth, we support folks in understanding themselves more deeply, including learning how their brains work, what their needs are, and how to advocate for what they need to thrive in a world that is not designed for neurodivergent brains. Reach out today to find a therapist who can help you live a fuller life.

References

Curtis, L. (2025, May 30). ADHD vs. autism: Understanding differences, similarities, and overlap. Verywell Health. https://www.verywellhealth.com/adhd-vs-autism-11718340

Mcgarrie, J. (2025, November 24). ADHD vs autism: Understanding the differences and similarities. The ADHD Centre. https://www.adhdcentre.co.uk/adhd-vs-autism-understanding-the-differences-and-similarities/

Vroman, J. (n.d.). The female neurodivergent experience. Psychology Today. https://www.psychologytoday.com/us/blog/divergent-minds/202502/the-female-neurodivergent-experience?msockid=337055a4b02d65fa112140c7b1876495